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Library Tech Library Tech => 289/302 - non-stroker combos => Topic started by: NIKwithoutaC on May 31, 2011, 12:39:05 pm



Title: My stab at the big head/small engine build.
Post by: NIKwithoutaC on May 31, 2011, 12:39:05 pm
The engine is actually finished and in the car, and I've been driving it for a few days.  Thought I'd make sure it was actually going to work before I drew any attention to myself on this forum.  :D

The car is an '86 GT (see sig) with the stock 90K mile 302 bottom end, but I sent the block and crank to the machine shop for some cleanup work while I had it out, and then I put new rings, bearings, oil pump, etc in the car while I had it out.

Here is the list of top end parts:

TEA prepped Twisted Wedge 205s.  Double springs with Ti retainers.  Milled to 61cc (9.8ish CR).
TFS R intake w/90mm TB opening, TEA port matched to the heads.
Custom Comp cam.  215/224 @ .050", ~.570" I & E lift w/1.6 rocker, 112 LSA.
70mm throttle body (it's what I had, the car will get a 90 eventually).
4" intake pipe and 97mm Abaco MAF meter.

Other stuff:

Junk BBK equal length shorty headers
"Off road" 2.5 inch x-pipe, Flowmaster 2.5 inch cat-back
255lph fuel pump, 30lb injectors
3.73 gears
Asto Performance T5, Ram HDX clutch
E-fan and a bunch of other little stuff I'm forgetting

Anyway, the clutch is still in the break in period, so I have not thrashed on it too much, but I can say this:  I can lug the engine down to 1200 RPM or so, no bucking, perfect drivability.  The engine is pulling very hard at 5500 rpm, though I have not really taken it past that yet.  I imagine it will pull strong all the way until the computer tugs on the leash and cuts fuel at whatever the factory rev limiter is.  I'll eventually have drag strip and dyno results, though it is more of a street car and less of a drag car.

The full build thread is HERE. (http://www.stangnet.com/mustang-forums/833852-nikwoacs-commitment-issues-engine-build.html)  I know, I know, I'm a StangNet junky.  :P

Comments?  Questions?  Concerns?  ;D


Title: Re: My stab at the big head/small engine build.
Post by: David Claflin on May 31, 2011, 12:43:11 pm
Sounds similar to what I was going to do with my '88GT, only difference would be the exhaust and going to go with a vic jr intake and a 4 hole throttle body.
Do you know the rest of the specs on the cam? Who did that for you?


Title: Re: My stab at the big head/small engine build.
Post by: NIKwithoutaC on May 31, 2011, 02:41:09 pm
Yea, I have the cam card at home.  Duration at .006" is 265/276, actual lobe lift is .355/.354.  I installed/degreed the cam "straight up".

Mike at TEA helped me spec the cam.  I kind of had an idea* of what the cam should look like, and he helped me by finalizing the actual lobes used.  It's roughly based off a Comp XE 266, but with more lift.  I don't have the part numbers in front of me, but I believe the intake lobe is one of Comp's LS lobes, and the exhaust is one of their XFI lobes.

*Disclaimer:  I do not consider nor advertise myself to be a cam expert.  I just did a lot of research, played with CamQuest, and read about a lot of other people's cars and what cams worked for them.  The cam is probably not perfect for my application, but I'm happy with how the car runs so far.  ;D


Title: Re: My stab at the big head/small engine build.
Post by: Joel5.0 on May 31, 2011, 03:35:05 pm
XTREME ENERGY LSL Lobe #13014: 265 215 139 .355 .568
Xtreme XFI Lobe #3035: 276 224 147 .353 .565

On a 112 LSA "straight up" or ICL = LSA = 4.5 ATDC/39.5 ABDC Intake and 44 BBDC/0 BTDC exhaust.

 :wonder: .... for comparison purposes, check the example at http://sbftech.com/index.php/topic,2245.msg51814.html#msg51814


Title: Re: My stab at the big head/small engine build.
Post by: David Claflin on May 31, 2011, 03:40:24 pm
Should run pretty good I'd think, especially with a good tune in it.


Title: Re: My stab at the big head/small engine build.
Post by: NIKwithoutaC on May 31, 2011, 04:14:53 pm
XTREME ENERGY LSL Lobe #13014: 265 215 139 .355 .568
Xtreme XFI Lobe #3035: 276 224 147 .353 .565

On a 112 LSA "straight up" or ICL = LSA = 4.5 ATDC/39.5 ABDC Intake and 44 BBDC/0 BTDC exhaust.

 :wonder: .... for comparison purposes, check the example at http://sbftech.com/index.php/topic,2245.msg51814.html#msg51814

Haha, I think you're right on the money with those lobes, Joel.  I have the Comp catalog PDF on my computer, but I'm too lazy to look through it.  :P

I have actually, at some point, read those posts.  It was stuff like that that helped me pick my cam.  I had originally wanted to run 1.7 rockers and end up with .600" lift, but Mike suggested that I run 1.6s and save on spring life and to go easy on the rest of my valvetrain.  Besides, it's not like those 205s aren't moving enough wind already at .568".  ;D

Should run pretty good I'd think, especially with a good tune in it.

I'm happy with how it runs, and judging by how it's pulling at 4000rpm and beyond, I'm guessing it will hold it's own at the track.  I agree, there will probably be some tuning to get the most out of it, but right now I already blew the budget and the wife probably won't let me buy a tuner.   :D  I have an adjustable fuel pressure regulator sitting on the shelf, so in the mean time I'll just read plugs and get the A/F close.  Beyond that, I do have some bugs to work out, but right now I'm enjoying just driving the thing.


Title: Re: My stab at the big head/small engine build.
Post by: jtmustang on May 31, 2011, 04:28:04 pm
cool build... ;D

any pics of the car itself and inside ..etc..?


Title: Re: My stab at the big head/small engine build.
Post by: NIKwithoutaC on May 31, 2011, 05:01:02 pm
cool build... ;D

any pics of the car itself and inside ..etc..?

Thanks, man!

Yea, I've got a few shots of the car.  The body is straight and rust free, but the paint is definitely showing its age.  The interior is pretty clean, aside from a rip in the driver's seat from sliding into it with cargo shorts that had metal buttons on them, haha.

Other mods to the car include a full 5-lug swap with 2004 Cobra brakes and 17x8/17x9 Mach 1 wheels.  I've had this car since I was 17 and have done every last modification entirely myself, the car was stone stock when I bought it.  Well, I take that back, my wife helped me bleed the brakes after the 5 lug swap.  :P

Pics:

(http://i242.photobucket.com/albums/ff95/nikwoac/The%2086/IMG_0949.jpg)

(http://i242.photobucket.com/albums/ff95/nikwoac/The%2086/IMG_0947.jpg)

(http://i242.photobucket.com/albums/ff95/nikwoac/The%2086/IMG_0952.jpg)

(http://i242.photobucket.com/albums/ff95/nikwoac/Random/SL3.jpg)

Thought I had more of the interior, guess not.  :msorry:


Title: Re: My stab at the big head/small engine build.
Post by: Joel5.0 on May 31, 2011, 06:09:55 pm
Disconnect the O2's, clear computer memory, install FPR, lock timing at what it likes after some test runs between 30 - 35 and check what fuel pressure it works best with.....  :naughty:


Title: Re: My stab at the big head/small engine build.
Post by: David Claflin on May 31, 2011, 09:06:32 pm
Here's the link to the HC50 thread mentioned in reply from Jay, the link in there was dead.
http://hardcore50.com/vbulletin/showthread.php?p=309642
The cam in the one DB built is significantly larger then what you have, or what I intend to use in mine.


Title: Re: My stab at the big head/small engine build.
Post by: goober on June 01, 2011, 12:51:30 am
Here's the link to the HC50 thread mentioned in reply from Jay, the link in there was dead.
http://hardcore50.com/vbulletin/showthread.php?p=309642
The cam in the one DB built is significantly larger then what you have, or what I intend to use in mine.

Good link! That engine was making some steam!


Title: Re: My stab at the big head/small engine build.
Post by: NIKwithoutaC on June 01, 2011, 07:17:17 am
Disconnect the O2's, clear computer memory, install FPR, lock timing at what it likes after some test runs between 30 - 35 and check what fuel pressure it works best with.....  :naughty:

 :ahprepare:

Why lock timing?  Why not just play with my initial timing?

Here's the link to the HC50 thread mentioned in reply from Jay, the link in there was dead.
http://hardcore50.com/vbulletin/showthread.php?p=309642
The cam in the one DB built is significantly larger then what you have, or what I intend to use in mine.

Yea, that cam is waaaaaaaaay bigger than what I'd run, haha.  But that 302 is baking some power!


Title: Re: My stab at the big head/small engine build.
Post by: David Claflin on June 01, 2011, 07:46:52 am
Why lock timing?  Why not just play with my initial timing?
If you tune it yourself you can set initial timing apart from wide open throttle timing. If you advance timing 8 degrees to 18 initial, it is still only 34 total at WOT


Title: Re: My stab at the big head/small engine build.
Post by: Joel5.0 on June 01, 2011, 08:01:54 am
Just wanted to use Nik's engine removal/disassembly pictures to show you guys something. If you look at the pictures of the different SBF timing covers based on water pump rotation shown at http://sbftech.com/index.php/topic,2441.0.html ..... and compare the OEM timing cover of his '86 HO (a reverse rotation WP)..... you will see that the WP ports are aligned/oriented just like the regular rotation WP timing covers. IOW.... they are interchangeable w/out affecting water flow.

(http://sbftech.com/index.php?action=dlattach;topic=2441.0;attach=3068;image)

(http://i242.photobucket.com/albums/ff95/nikwoac/The%2086/DSCN0215.jpg)

Disconnect the O2's, clear computer memory, install FPR, lock timing at what it likes after some test runs between 30 - 35 and check what fuel pressure it works best with.....  :naughty:

 :ahprepare:

Why lock timing?  Why not just play with my initial timing?

You take the stock timing advance variable out of the picture and set for what the engine benefits from mechanically, until you have access to the QH that you plan to install. It's also an old school trick that does work at the track. Test it and see for yourself.


Title: Re: My stab at the big head/small engine build.
Post by: NIKwithoutaC on June 01, 2011, 09:18:19 am
If you tune it yourself you can set initial timing apart from wide open throttle timing. If you advance timing 8 degrees to 18 initial, it is still only 34 total at WOT

Iiiiiiiiiiiiiiiiiiiiinteresting.  I was not aware of this.  I was always under the impression that by altering the base timing, you were inadvertently altering total timing.

Just wanted to use Nik's engine removal/disassembly pictures to show you guys something. If you look at the pictures of the different SBF timing covers based on water pump rotation shown at http://sbftech.com/index.php/topic,2441.0.html ..... and compare the OEM timing cover of his '86 HO (a reverse rotation WP)..... you will see that the WP ports are aligned/oriented just like the regular rotation WP timing covers. IOW.... they are interchangeable w/out affecting water flow.

(http://sbftech.com/index.php?action=dlattach;topic=2441.0;attach=3068;image)

(http://i242.photobucket.com/albums/ff95/nikwoac/The%2086/DSCN0215.jpg)

You take the stock timing advance variable out of the picture and set for what the engine benefits from mechanically, until you have access to the QH that you plan to install. It's also an old school trick that does work at the track. Test it and see for yourself.

It looks like the 351 timing cover is the only one with different ports...  Correct?

I'll have to try that timing trick next time I'm at the track.  Unfortunately, I live in familyland suburbville, so I can't just take the car out and thrash on it on public roads without drawing a lot of attention to myself and running into a lot of slow moving traffic.  Unless, of course, I want to drive 30 minutes to get out into the country.  :duh


Title: Re: My stab at the big head/small engine build.
Post by: David Claflin on June 01, 2011, 10:48:16 am
If you tune it yourself you can set initial timing apart from wide open throttle timing. If you advance timing 8 degrees to 18 initial, it is still only 34 total at WOT

Iiiiiiiiiiiiiiiiiiiiinteresting.  I was not aware of this.  I was always under the impression that by altering the base timing, you were inadvertently altering total timing.
You do, if you set initial timing plus 8, you're setting WOT timing plus 8; unless you do the tune via quarterhorse. Then you can set initial plus 3 or 4, and WOT timing plus 9, like what I did on my son's 94 GT with iron heads. Just that change, and WOT fuel make some good improvements at the track, and he still knocks down 20MPG driving back and forth to school and work


Title: Re: My stab at the big head/small engine build.
Post by: 68mustang405 on June 01, 2011, 04:15:11 pm
Joel thank you!  :smile I've been trying to tell people that forever. They just don't listen. Whys it matter what the ports look like on the timing cover when the outlet port on the water pump is round?  :wonder:


Title: Re: My stab at the big head/small engine build.
Post by: David Claflin on June 19, 2011, 06:44:34 pm
Any idea when you're getting this to the dyno or track?


Title: Re: My stab at the big head/small engine build.
Post by: NIKwithoutaC on June 20, 2011, 11:00:10 am
Just ordered a new helmet, should be in this week.  Car has just a touch over 400 miles on it since the rebuild, clutch calls for a 500 mile break in, but eh, close enough, right?  Haha.

Anyway, the soonest test and tune night that I'll probably make it to is next Wednesday, weather pending.

I have no idea when it will hit the dyno.  Sometime this summer probably.  I want to put a wideband A/F gauge in the car and do a little tweaking myself.  When the car goes to the dyno, it will be strictly for a power graph and bragging rights, NOT a dyno tune, I really want to do the tuning myself.  ;D


Title: Re: My stab at the big head/small engine build.
Post by: David Claflin on June 21, 2011, 10:15:44 pm
What are you going to tune it with? How's tha Abaco meter work for you?


Title: Re: My stab at the big head/small engine build.
Post by: NIKwithoutaC on June 21, 2011, 10:56:54 pm
What are you going to tune it with? How's tha Abaco meter work for you?

For the time being, I'm just going to play with the Abaco software (lets you play with the MAF transfer curve), though I'll probably dive into a Moates Quarterhorse before next season.

The Abaco meter seems to be doing a good job so far.  I don't have any significant drivability issues, though the car has a funky intermittent starting issue, but I have a hunch that has to do with the 30lb injectors and lack of a true tune.

I actually had some reservations about running a 97mm meter on a NA 302.  I was worried the low airspeed through the meter would cause sampling issues, but the tech at Anderson Ford Motorsport didn't even hesitate to recommend the 97 over the 85mm unit.  He basically told me that if I had the room, run the 97.  The way these meters sample the air you can basically clock it any way you want, before or after a turn, whatever.  If air is moving through the tube, the meter will read it.  My impression was that the 85mm meter is more aimed for systems where it can be more of a stock drop-in unit.  The 97mm obviously requires a custom 4" inlet system.


Title: Re: My stab at the big head/small engine build.
Post by: David Claflin on June 22, 2011, 08:42:25 am
I have a pro-m 92MM on my 306 daily driver and have no issues, it uses 4" inlet tubing as well. It starts and runs every time, the MAF curve I loaded isn't far off from the Pro-M curve loaded in EEC analyzer, just a bit leaner through the low-mid range.


Title: Re: My stab at the big head/small engine build.
Post by: NIKwithoutaC on June 22, 2011, 09:07:00 am
I have a pro-m 92MM on my 306 daily driver and have no issues, it uses 4" inlet tubing as well. It starts and runs every time, the MAF curve I loaded isn't far off from the Pro-M curve loaded in EEC analyzer, just a bit leaner through the low-mid range.

What size injectors are you running?  My car starts every time, but sometimes it cranks just a little too long before it catches for me to be comfortable with it.  Other times, it's like I turn the key, the engine rotates 10* and BLAM it's running.  It's weird.


Title: Re: My stab at the big head/small engine build.
Post by: David Claflin on June 22, 2011, 12:35:02 pm
30's


Title: Re: My stab at the big head/small engine build.
Post by: 90lxcoupe on June 22, 2011, 04:26:37 pm
Just ordered a new helmet, should be in this week.  Car has just a touch over 400 miles on it since the rebuild, clutch calls for a 500 mile break in, but eh, close enough, right?  Haha.

Anyway, the soonest test and tune night that I'll probably make it to is next Wednesday, weather pending.

I have no idea when it will hit the dyno.  Sometime this summer probably.  I want to put a wideband A/F gauge in the car and do a little tweaking myself.  When the car goes to the dyno, it will be strictly for a power graph and bragging rights, NOT a dyno tune, I really want to do the tuning myself.  ;D
My car quit being a street drive for a few years.  I would have never gotten to 500 miles on the clutch.  pretty much had from the garage to the trailer & trailer to staging lanes.  I took a few passes to adjust & then I let it rip.


Title: Re: My stab at the big head/small engine build.
Post by: David Claflin on June 23, 2011, 01:27:32 pm
I've been looking at the different lobes on comps master list, so far the XFI lobes are the only ones I've seen that offer short duration and high lift. I'll have to spring for pipe max and use the EA program to see what I can come up with for the 306 for my GT.


Title: Re: My stab at the big head/small engine build.
Post by: 93mustank on June 23, 2011, 02:20:26 pm
Wait all this stuff and 3.73s with shorty exhaust junk?  :duh


Title: Re: My stab at the big head/small engine build.
Post by: 68mustang405 on June 23, 2011, 04:30:55 pm
Just ordered a new helmet, should be in this week.  Car has just a touch over 400 miles on it since the rebuild, clutch calls for a 500 mile break in, but eh, close enough, right?  Haha.

Anyway, the soonest test and tune night that I'll probably make it to is next Wednesday, weather pending.

I have no idea when it will hit the dyno.  Sometime this summer probably.  I want to put a wideband A/F gauge in the car and do a little tweaking myself.  When the car goes to the dyno, it will be strictly for a power graph and bragging rights, NOT a dyno tune, I really want to do the tuning myself.  ;D
My car quit being a street drive for a few years.  I would have never gotten to 500 miles on the clutch.  pretty much had from the garage to the trailer & trailer to staging lanes.  I took a few passes to adjust & then I let it rip.

I was reading chevy performance or car craft or something under the write in columns and people were talking about the importance of wearing the clutch in because you're imbedding materials from the clutch into the flywheel to hold maxiumum power. If it get's to hot it'll glaze over. Kind the same concept with brake pads and bedding them in. At least that's what they were comparing them too. In a drag race it might not get hot enough to do any damage, but on the street i would bed it in completely.


Title: Re: My stab at the big head/small engine build.
Post by: NIKwithoutaC on June 23, 2011, 05:00:29 pm
I've been looking at the different lobes on comps master list, so far the XFI lobes are the only ones I've seen that offer short duration and high lift. I'll have to spring for pipe max and use the EA program to see what I can come up with for the 306 for my GT.

Well, like it was said before, the intake lobe is actually listed as a Chevy LS lobe.  You might look into those.

Wait all this stuff and 3.73s with shorty exhaust junk?  :duh

Street car street car street car street car street car street car.   ;D  This thing regularly sees highway and cruising speeds above 65, and I have no desire to be spinning the engine any higher than what it is already on the highway.

As for the headers: 1. The shorties were just what I already had   2. I have no desire to deal with the "inconveniences" of long tubes and   3. The car will very very likely have a turbo and/or a 351-based bottom end in another year or two, making spending any money on long tubes right now a waste.

I was reading chevy performance or car craft or something under the write in columns and people were talking about the importance of wearing the clutch in because you're imbedding materials from the clutch into the flywheel to hold maxiumum power. If it get's to hot it'll glaze over. Kind the same concept with brake pads and bedding them in. At least that's what they were comparing them too. In a drag race it might not get hot enough to do any damage, but on the street i would bed it in completely.

 :wonder:


Title: Re: My stab at the big head/small engine build.
Post by: David Claflin on June 23, 2011, 06:07:24 pm
Well, like it was said before, the intake lobe is actually listed as a Chevy LS lobe.  You might look into those.
I know, I was looking for smaller lobes then what you had with similar and higher lifts.


Title: Re: My stab at the big head/small engine build.
Post by: NIKwithoutaC on June 23, 2011, 09:13:51 pm
Well, like it was said before, the intake lobe is actually listed as a Chevy LS lobe.  You might look into those.
I know, I was looking for smaller lobes then what you had with similar and higher lifts.

Ah, gotcha.


Title: Re: My stab at the big head/small engine build.
Post by: liljoe07 on June 23, 2011, 09:39:03 pm
Kinda funny that the cam you had spec'd out, resembles the type of cam Jay does for the same type of combo combo. Mine for instance had the events at -3BTDC 39ABDC and 49BBDC -4ATDC  216 225 @.050 and .546 .552



Title: Re: My stab at the big head/small engine build.
Post by: NIKwithoutaC on June 24, 2011, 06:59:21 am
Kinda funny that the cam you had spec'd out, resembles the type of cam Jay does for the same type of combo combo. Mine for instance had the events at -3BTDC 39ABDC and 49BBDC -4ATDC  216 225 @.050 and .546 .552

When I started planning this build, I actually had intentions of having Jay grind my cam, but by the time I was actually ready to pull the trigger and empty my wallet, he had already stopped doing business after that big fiasco.


Title: Re: My stab at the big head/small engine build.
Post by: David Claflin on June 24, 2011, 11:29:49 am
Kinda funny that the cam you had spec'd out, resembles the type of cam Jay does for the same type of combo combo. Mine for instance had the events at -3BTDC 39ABDC and 49BBDC -4ATDC  216 225 @.050 and .546 .552
Didn't you have TW heads on a stock shortblock? I had ported Edelbrocks, on a 306, with a GT40 intake and longtubes
218 at .050 intake

227 at .050 exhaust

141 at .200 intake

149 at .200 exhaust

.362 lobe lift intake

.359 lobe lift exhaust

.580 lift on intake

.576 lift on exhaust

115.13 LSA

113.13 IC

117.12 EC

Intake Open .050 4 ATDC

Exhaust Open .050 50 BBDC

Intake Close  42 ABDC

Exhaust Close 3 ATDC


Title: Re: My stab at the big head/small engine build.
Post by: Joel5.0 on June 24, 2011, 12:24:59 pm
Kinda funny that the cam you had spec'd out, resembles the type of cam Jay does for the same type of combo combo. Mine for instance had the events at -3BTDC 39ABDC and 49BBDC -4ATDC  216 225 @.050 and .546 .552
Didn't you have TW heads on a stock shortblock? I had ported Edelbrocks, on a 306, with a GT40 intake and longtubes
218 at .050 intake

227 at .050 exhaust

141 at .200 intake

149 at .200 exhaust

.362 lobe lift intake

.359 lobe lift exhaust

.580 lift on intake

.576 lift on exhaust

115.13 LSA

113.13 IC

117.12 EC

Intake Open .050 4 ATDC

Exhaust Open .050 50 BBDC

Intake Close  42 ABDC

Exhaust Close 3 ATDC


Late opening and late closing when compared to some OTS stuff out there for ported Edelbrock's and GT40 intake........ :thinking: ...... :idea ...... there's a lot of information in those events alone when you look at the components they were designed for + they also explain the gains when the setup benefited from the better intake and bigger TB ...... :takenote:


Title: Re: My stab at the big head/small engine build.
Post by: NIKwithoutaC on June 24, 2011, 01:24:28 pm
Hmmmm....  Why do you suppose the late CLOSING?  Curious.


Title: Re: My stab at the big head/small engine build.
Post by: FivePointOhh on June 24, 2011, 01:36:34 pm
Hmmmm....  Why do you suppose the late CLOSING?  Curious.

because even after BDC the cylinder is still filling due to the inertia of the incoming intake charge...correct?


Title: Re: My stab at the big head/small engine build.
Post by: NIKwithoutaC on June 24, 2011, 01:47:45 pm
Hmmmm....  Why do you suppose the late CLOSING?  Curious.

because even after BDC the cylinder is still filling due to the inertia of the incoming intake charge...correct?

Well, right.  Cams typically close the intake ABDC.  This one is just later than one might guess it to be.


Title: Re: My stab at the big head/small engine build.
Post by: FivePointOhh on June 24, 2011, 01:52:11 pm
Hmmmm....  Why do you suppose the late CLOSING?  Curious.

because even after BDC the cylinder is still filling due to the inertia of the incoming intake charge...correct?

Well, right.  Cams typically close the intake ABDC.  This one is just later than one might guess it to be.
what makes you say that? is that you saying it or the average gear head?


Title: Re: My stab at the big head/small engine build.
Post by: NIKwithoutaC on June 24, 2011, 02:04:53 pm
Hmmmm....  Why do you suppose the late CLOSING?  Curious.

because even after BDC the cylinder is still filling due to the inertia of the incoming intake charge...correct?

Well, right.  Cams typically close the intake ABDC.  This one is just later than one might guess it to be.
what makes you say that? is that you saying it or the average gear head?

Both?  If you look at the specs above, it "closes" at 42 ABDC, whereas mine "closes" at 39.5.  His just closes later.


Title: Re: My stab at the big head/small engine build.
Post by: Joel5.0 on June 24, 2011, 06:27:58 pm
Hmmmm....  Why do you suppose the late CLOSING?  Curious.

because even after BDC the cylinder is still filling due to the inertia of the incoming intake charge...correct?

Well, right.  Cams typically close the intake ABDC.  This one is just later than one might guess it to be.
what makes you say that? is that you saying it or the average gear head?

Both?  If you look at the specs above, it "closes" at 42 ABDC, whereas mine "closes" at 39.5.  His just closes later.

NIK.... look at the components in the combo. For your reference a X-303 or Stg 2 or XE270HR cam closes the intake at 39 ABDC and others with a higher intake duration are in the 40-42 ABDC range. Why would you you set/configure a small duration lobe to close later with those intake components installed? .... and no, it goes beyond the obvious physics answer, do not overlook the late intake opening.


Title: Re: My stab at the big head/small engine build.
Post by: David Claflin on June 26, 2011, 10:56:14 am
Joel,

Do you think this should be broken off into it's own thread? I've found some other links about small cams and big heads, including those here.


http://sbftech.com/index.php/topic,2245.msg51814.html#msg51814

http://sbftech.com/index.php/topic,30565.0.html

http://hardcore50.com/vbulletin/showthread.php?p=309642

http://hardcore50.com/vbulletin/showthread.php?t=48922

http://hardcore50.com/vbulletin/showthread.php?t=57508

http://forums.corral.net/forums/5-0-5-8-engine-tech/646936-big-head-small-cam-theories.html


Title: Re: My stab at the big head/small engine build.
Post by: liljoe07 on June 26, 2011, 02:27:00 pm
Kinda funny that the cam you had spec'd out, resembles the type of cam Jay does for the same type of combo combo. Mine for instance had the events at -3BTDC 39ABDC and 49BBDC -4ATDC  216 225 @.050 and .546 .552
Didn't you have TW heads on a stock shortblock? I had ported Edelbrocks, on a 306, with a GT40 intake and longtubes
218 at .050 intake

227 at .050 exhaust

141 at .200 intake

149 at .200 exhaust

.362 lobe lift intake

.359 lobe lift exhaust

.580 lift on intake

.576 lift on exhaust

115.13 LSA

113.13 IC

117.12 EC

Intake Open .050 4 ATDC

Exhaust Open .050 50 BBDC

Intake Close  42 ABDC

Exhaust Close 3 ATDC


Nope David, I have Canfields.

So here is the full list of specs on my cam. With a correction to the intake lift since I typoed it.

           Intake        Exhaust
.006       266             275
.020       243             252
.050       216             225
.200       142             148

Lobe Lift .352            .345

Lobe Cent 111           116

open      -3BTDC        49BTDC
close       39ABDC       -4ATDC


Title: Re: My stab at the big head/small engine build.
Post by: NIKwithoutaC on June 27, 2011, 09:14:59 am
Joel,

Do you think this should be broken off into it's own thread? I've found some other links about small cams and big heads, including those here.


http://sbftech.com/index.php/topic,2245.msg51814.html#msg51814

http://sbftech.com/index.php/topic,30565.0.html

http://hardcore50.com/vbulletin/showthread.php?p=309642

http://hardcore50.com/vbulletin/showthread.php?t=48922

http://hardcore50.com/vbulletin/showthread.php?t=57508

http://forums.corral.net/forums/5-0-5-8-engine-tech/646936-big-head-small-cam-theories.html


MMM-mmm.  Love me some big head/small engine.  Good stuff.

Nope David, I have Canfields.

So here is the full list of specs on my cam. With a correction to the intake lift since I typoed it.

           Intake        Exhaust
.006       266             275
.020       243             252
.050       216             225
.200       142             148

Lobe Lift .352            .345

Lobe Cent 111           116

open      -3BTDC        49BTDC
close       39ABDC       -4ATDC

What kind of numbers do the Canfields post on the flow bench?


Title: Re: My stab at the big head/small engine build.
Post by: liljoe07 on June 27, 2011, 10:22:40 am
I believe Stan Weiss has numbers around 280cfm @ .600. Jays site had 275cfm @ .600.


Title: Re: My stab at the big head/small engine build.
Post by: jayh on June 27, 2011, 07:50:01 pm
http://forums.corral.net/forums/5-0-5-8-engine-tech/646936-big-head-small-cam-theories.html

that was an interesting read all things considered


Title: Re: My stab at the big head/small engine build.
Post by: David Claflin on July 02, 2011, 07:34:03 pm
http://forums.corral.net/forums/5-0-5-8-engine-tech/646936-big-head-small-cam-theories.html

that was an interesting read all things considered
I liked it too, aside from the drama, there's a good amount to pick up there.


Title: Re: My stab at the big head/small engine build.
Post by: David Claflin on July 24, 2011, 06:43:20 pm
Came across this today while doing a search
http://sbftech.com/index.php/topic,22241.0.html


Title: Re: My stab at the big head/small engine build.
Post by: David Claflin on August 16, 2011, 02:01:05 pm
Have you made it to the track or dyno yet??


Title: Re: My stab at the big head/small engine build.
Post by: NIKwithoutaC on August 17, 2011, 05:43:46 pm
Had it to the track once, where a failing clutch cable (one of those damn adjustable units with a bunch of miles on it) prevented me from getting any clean shifts in.  Made a couple retarded passes out of frustration grinding gears and going 14s at ~104.

Limped the car home, yanked that cable, and it looked like this:

(http://i242.photobucket.com/albums/ff95/nikwoac/The%2086/DSCN0631.jpg)

Then I stuck a generic parts store non-adjustable cable in with a firewall adjuster.  That cable snapped after just a couple days of driving.  Don't have a picture of it, but it looked much worse than the one above.

Then the car sat for a week, and then I finally got around to ordering a proper cable from Maximum Motorsports (night and day clutch pedal feel, BTW), and I've been putting miles on the car ever since to see if this cable will last.  It's been working, but it has started to produce an odd clicking feel on my foot intermittently when I push in the clutch, which makes me nervous.

I don't know what's going on, but it ain't right.  I've been dreading it, but I think I need to pull the quadrant and inspect everything.  Everything underneath the car appears OK, so I don't know what else it could be.


Title: Re: My stab at the big head/small engine build.
Post by: jayh on August 17, 2011, 11:04:31 pm
Came across this today while doing a search
http://sbftech.com/index.php/topic,22241.0.html


Im sorry but 224@.050 isnt big. think about it. that cam might have worked decent, look at the application. I wish Jay was still around and respected his opinions but if you go farther back in time he used to suggest the holley and his early days he actually modeled up a combo and suggested a 274hr for a 302, smaller head though, but similar cam.


Title: Re: My stab at the big head/small engine build.
Post by: David Claflin on August 19, 2011, 05:26:59 pm
I was thinking it would depend on the usage, the one DB did with a 310, had 205's on it and he made 500+HP with it, but he spun it higher. If the guy wanted something smooth with a 6K redline something smaller camwise would be better.


Title: Re: My stab at the big head/small engine build.
Post by: NIKwithoutaC on September 22, 2011, 09:23:16 am
Took it to the track, little update-

As some of you guys know, ever since I finished my build, the car was plagued with some clutch cable issues, along with a few other small issues that I had to resolve. I had kind of been procrastinating working on it and all summer and just enjoying driving it, but last weekend I finally spent some time wrenching on it, and last night I had it on the track. Results below. Keep in mind, this is a full weight car, granny shifting on 17" street tires.

Run 1:
(3rd gear took me a couple tries... Someday I'll figure out this "driving" thing!)
60'--2.165
1/8--8.926
1/4--13.613 @ 106.45

Run 2:
(Totally walked a C5 'Vette on this run. Damn, that was satisfying.)
60'--2.206
1/8--8.751
1/4--13.336 @ 108.22

Run 3:
60'--2.209
1/8--8.750
1/4--13.307 @ 108.77

Run 4:
(Best run, and last run before they closed the track.)
60'--2.105
1/8--8.581
1/4--13.107 @ 109.33


So, I'm really confident the thing has 12s in it, as it sits, with just a little better driving. I think there is a LOT to be had in just tweaking the car itself, without touching the motor. Tune, raise the limiter so I can shift at 63-6500, 15" stickies and skinnies, and a few other things and I think this car will be much, much faster.

Thoughts?


Title: Re: My stab at the big head/small engine build.
Post by: HIGHVOLTJ on September 22, 2011, 01:43:18 pm
Need tires and a harder launch for sure, there is probably .5 there, the 60ft is way soft.


Title: Re: My stab at the big head/small engine build.
Post by: mighty mouse on September 22, 2011, 02:09:51 pm
110mph is bottom 12s.  Not just 12s.

You get your 60' to the 1.6 area and you have your bottom 12's.

At this point - I wouldnt think of touching the engine.  Some sticky tires and probably some suspension work will go a LONG LONG way!


Title: Re: My stab at the big head/small engine build.
Post by: NIKwithoutaC on September 22, 2011, 02:24:22 pm
110mph is bottom 12s.  Not just 12s.

You get your 60' to the 1.6 area and you have your bottom 12's.

At this point - I wouldnt think of touching the engine.  Some sticky tires and probably some suspension work will go a LONG LONG way!

That's what I'm thinking.  At this point, I'm confident I've got the motor to go much faster, I just need to look for it in the rest of the car and also in my driving.

I've been window shopping 15" drag wheels all day, haha.


Title: Re: My stab at the big head/small engine build.
Post by: 85_GT on September 22, 2011, 05:22:09 pm
What gears?


Title: Re: My stab at the big head/small engine build.
Post by: David Claflin on September 22, 2011, 06:39:10 pm
What gears?
3.73's, first page

Not bad for a first time out, as has been mentioned sticky tires and seat time will help a lot. For comparisons sake, I had mine at a quarter mile track in Iowa last summer. Heat of the summer, no icing the intake, passenger headlight in, on 17" street tires. I managed a best 60 ft of 2.6, all my runs that I stayed in it were 13.3 @ 110. When I got back here I went to the track and ran 8.5's@84 on street tires again, pulled the headlight and iced the intake and dropped 3/10 and added 3MPH. With slicks, cool air and the driver mod you might squeeze a high 11 out of it.


Title: Re: My stab at the big head/small engine build.
Post by: NIKwithoutaC on September 23, 2011, 10:07:05 am
Not bad for a first time out, as has been mentioned sticky tires and seat time will help a lot. For comparisons sake, I had mine at a quarter mile track in Iowa last summer. Heat of the summer, no icing the intake, passenger headlight in, on 17" street tires. I managed a best 60 ft of 2.6, all my runs that I stayed in it were 13.3 @ 110. When I got back here I went to the track and ran 8.5's@84 on street tires again, pulled the headlight and iced the intake and dropped 3/10 and added 3MPH. With slicks, cool air and the driver mod you might squeeze a high 11 out of it.

Not sure I'll ever have the driver mod, haha.  But yea, I think with some sticky tires and some better driving, mid 12s at 112 maybe...?  We'll see.  I kind of want to crack 12s on street tires, exactly as the car sits now, then maybe before next season starts, pick up a set of stickies and skinnies for it, a Quarterhorse and a few other things, and really get serious.


Title: Re: My stab at the big head/small engine build.
Post by: 289nate on September 23, 2011, 12:51:49 pm
Very respectable considering your 60 ft time and full weight vehicle.  As others have said, you have a ton left in it.  The 60 ft is terrible but to be expected on street tires and your first time out with it.  12's are a cake walk with slicks. 

I feel 11's are a very realistic long term goal.  Right now your best friends will be slicks and getting some passes under your belt with this new combo.


Title: Re: My stab at the big head/small engine build.
Post by: NIKwithoutaC on September 23, 2011, 01:40:31 pm
Not bad for a first time out, as has been mentioned sticky tires and seat time will help a lot. For comparisons sake, I had mine at a quarter mile track in Iowa last summer. Heat of the summer, no icing the intake, passenger headlight in, on 17" street tires. I managed a best 60 ft of 2.6, all my runs that I stayed in it were 13.3 @ 110. When I got back here I went to the track and ran 8.5's@84 on street tires again, pulled the headlight and iced the intake and dropped 3/10 and added 3MPH. With slicks, cool air and the driver mod you might squeeze a high 11 out of it.

Just curious David, what do you shift your car at?


Title: Re: My stab at the big head/small engine build.
Post by: David Claflin on March 02, 2012, 11:56:27 am
Just curious David, what do you shift your car at?
Just noticed the reply on here. I think I had the shift light set at 5600 or so.