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Author Topic: detonation prevention open chamber head???  (Read 28376 times)
Brian S
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« Reply #15 on: February 04, 2011, 03:04:55 am »

On compression I was using the keith black compression calculator. thanks and talk soon.

I guess you mean this one.
http://www.kb-silvolite.com/calc.php?action=comp
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wyoming4x4
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« Reply #16 on: February 04, 2011, 01:05:53 pm »

 yes. Cam spec for a 400 ford 4v head hyd roller towing/highway. CR272 gross vlv in. .520 exh. .520, advertised int. 272, exh .280. duration at .050 int. 210, exh. 214. drop in at .050 vlv timing 108. intake -3 btdc, close abdc 33. exh bbdc 43, atdc -9. lobe lift .300 int, .300 exh. lobe seperation 112. intersting cam and curious to run. little different than what I have run in the past.  hope this helps and curious to you numbers. block is back from line hone and will be decking the block next week. Any good input is welcome and catch you later.
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wyoming4x4
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« Reply #17 on: February 04, 2011, 01:13:09 pm »

for got to mention when having cam built my request was to make peak torque in the 3000 to 3500 rpm range. To me the torque is what I watch the most for this application. Did a similar cam in a 472 big block ford and its awesome cam. Scott calls it dieseling cam. catch you later hope this helps on info. time for lunch in wyoming, see ya!
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Brian S
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« Reply #18 on: February 04, 2011, 07:58:00 pm »

I'm not really impressed with the KB calculator, the intake closing point @ .050 +15 degree gives a false high reading for dynamic compression. However when I tried it with your numbers I got the same static compression of 10.17 as before and 9.04 for dynamic but it's still showing more than it should IMO.

Cylinder Head Volume (cc) 73        Cylinder Head Vol (cubic in.)     4.453
Piston Head Volume (cc) 3      Piston Head Vol (cubic in.)    0.183
Gasket Thickness (in.) .051      Swept Volume (cubic in.)    51.022
Gasket Bore (in.) 4.1      T.D.C. Volume (cubic in.)    5.564
Cylinder Bore Diameter (in.) 4.03      Gasket Volume (cubic in.)    0.673
Deck Clearance (in.) .020   Deck Volume (cubic in.)    0.255
Stroke (in.) 4.0      
STATIC COMPRESSION RATIO 10.170

OPTIONAL DATA
Rod Length (in.) 6.58       Adjusted Stroke (in.)    3.508
Intake Closing Point (degrees)ABDC @ 0.050 lift 33 plus 15 degrees = 44        
DYNAMIC EFFECTIVE COMPRESSION RATIO 9.042

If you use the same numbers I did the results should be the same.

OK, this is what your cam and some other numbers show on my calculator.

Displacement: 408.18       Static CR: 10.17       DeckClearance: .020       QuenchDistance: .071   
IntakeOpens: 28 BTDC      IntakeCloses: 64 ABDC      ExhaustOpens:   76 BTDC   ExhaustCloses:   24 ATDC
Overlap: 52      Intake CL:   108   Exhaust CL: 116   
Dynamic CR: 8.17      Cranking Comp:   179   R/S Ratio:   1.65
Piston Speed:   6569 FPM   @ Angle: 74.4 ATDC      TDC Accel:   -2666 G

At 4000 Altitude the only change is Cranking Compression: 154

You're gonna try to run basically an RV cam with high compression so I would proceed with caution but since you're going away for a few days I'll post a little more info later.

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wyoming4x4
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« Reply #19 on: February 05, 2011, 12:14:25 am »

thanks for checkin in and interesting numbers. this is my first hyd roller in a 400. I've ran higher compression with a similar cam in a 351 cleveland and open chamber head with dome piston and didn't have problems. now doing similar application with 400" application. another situation is my transmission is a 5 speed manual and 4.10 gears on 33" tire. Helps keep the lugging to a minimum. I was thinking my compression is in question and what are you thinking on compression? The one big factor for my application you can't see is my elevation changes. 5000' to 7000' are just up the road and these are my normal conditions. basically trying to cheat the elevation with some compression. Also 9800' elevation is usually my highest place I play at. not much horsepower up their. when at these elevations my air temps are usually down and often become a positive factor even in summer application. brian thanks for your excellent info.
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wyoming4x4
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« Reply #20 on: February 05, 2011, 12:26:06 am »

New problem! this morning did a crank mock up and checkin bearing clearance. Block was lined hone and rechecking everything. My bearing clearance is tight and my crank guy will be adding some clearance. All my bearing checks at .0018 to .002. dan gonna give me some more clearance to about .0022 give or take a little. My real problem is when mocking up heads on block my combustion chambers are not center perfect over cylinder bore. Everything is off about .050 and need to move heads in towards intake about this much and will be good. Old iron and questionable machineing back in the day crap. Gonna have to do some creative thinking to help center the combustion chambers over cylinder bore. Had to stop and get prepared for my trip and will continue next week. Shooting the wyoming state archery tournament NFAA santioned shoot. Big deal to shoot well. Won my class last year and hope to do the same. thanks again on info.
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wyoming4x4
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« Reply #21 on: February 05, 2011, 12:34:37 am »

My question is when calculating the intake closing point why add 15 degree's never ran this program and curious why this happens or number comes from?? thanks and its snowing now.
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Brian S
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« Reply #22 on: February 05, 2011, 01:43:00 am »

My question is when calculating the intake closing point why add 15 degree's never ran this program and curious why this happens or number comes from?? thanks and its snowing now.

United Engine & Machine Co. Incorporated
http://www.kb-silvolite.com/calc.php?action=comp

When I try it using my data it appears to show almost a full point higher dynamic compression than other calcs I've tried using the same data. Can you confirm all the numbers I used in Bold text?

COMPRESSION RATIO CALCULATOR
Static and Dynamic Compression Ratio
(Considers Cam Timing and Rod Ratio)

ENTER YOUR DATA    CALCULATED DATA
Cylinder Head Volume (cc) 73      Cylinder Head Vol (cubic in.)    4.453
Piston Head Volume (cc) 3       Piston Head Vol (cubic in.)    0.183
Gasket Thickness (in.) .051      Swept Volume (cubic in.)    51.022
Gasket Bore (in.) 4.10      T.D.C. Volume (cubic in.)    5.564
Cylinder Bore Diameter (in.) 4.030      Gasket Volume (cubic in.)    0.673
Deck Clearance (in.) .020 Note: Neg. nubmer above deck, Pos. number below deck       Deck Volume (cubic in.)    0.255
Stroke (in.) 4.0      
STATIC COMPRESSION RATIO
   
10.170 Static Compression
OPTIONAL DATA
Rod Length (in.) 6.58    Adjusted Stroke (in.)    3.508
Intake Closing Point 33 (degrees)ABDC @ 0.050 lift plus 15 degrees         
DYNAMIC EFFECTIVE COMPRESSION RATIO 9.042
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Brian S
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« Reply #23 on: February 05, 2011, 07:45:29 pm »

If you haven't done a mock of with the ZF trans yet, you may want to check it before it's in the truck. The trans bolt patterns on 400s and 460s are the same but when swapping I've read about some guys who've run into issues with the input shaft length being 1/2-3/4" too long. After bolting up the shaft pushed so hard on the back of the crank that the engine wouldn't turn over. When and if you check it, make sure you have the pilot bearing already installed in the crank.

4.10s may sound like low gears but they really aren't when using 33" tires. They're about equal to a passenger car with 3.25s and 26" tires. Is 5th gear an overdrive on a the ZF? I'm not that familiar with the ratios.

I think the compression is borderline, that's why I'm trying to go over it so much detail. Originally you said 9.6 but I thought you meant that as static. After I figured out you meant dynamic, I was sure 9.6 wasn't right so I'm still trying to verify all the numbers. My guess is you used the KB calculator with 33 deg instead of 48 for the input. Valve events at .050 aren't normally used to determine DCR. The KB calculator is the only one I've come across that measures it that way. Most likely they add 15 degrees to the intake valve closing point because they attempt to estimate the advertised duration but it's not accurate for most cams. The actual closing point of your intake valve is 64 ABDC not 48.

When using 64 IVC on my calculator I got 8.17 DCR
On the online http://www.wallaceracing.com/dynamic-cr.php calculator I got 8.18
and Dan Weiss from http://users.erols.com/srweiss/index.html checked the compression on one of his calculators and got 8.165 so they are all very close except for the one from KB, but...if I use 64 instead of 48 on the KB site guess what I got......8.169. So at least there is some consistency when using the same advertised valve closing events.

Altitude is a factor I don't want to get into too much just yet but you really can't cheat a whole lot by using more compression. At high elevations there is less oxygen available so really the only way to cheat it (except nitrous or compressed O2) is with a supercharger, turbo or some type of forced induction. Dyno tests have shown raising compression on an open chamber head a full point such as 9:1 to 10:1 is only worth 4 to 5% more power.

As far as the heads being off, I'm not sure how you determined this. What are you seeing that gives you that impression?

Anyway, I have a bunch of reference material on the compression subject but I don't want to bombard you with so much info that your head explodes. I'll get into why I think 8.17 is borderline a bit later.
Here's a chart to look over before we pick up the topic again. You can see why when you mentioned 9.6 I knew something was up.
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wyoming4x4
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« Reply #24 on: February 06, 2011, 09:32:52 pm »

 on the heads I bolted up on my bare block and just took a look and seen where the combustion chamber sets on block. On a smaller combustion chamber I like to work the intake for shrouding issues if possible. bolt down block and flip over and scribe the cylinder head and see if i can improve things especially with a factory type heads. Always something you can do to improve on a factory head. When lookin at combustion chamber from bottom of block the heads are about .050 offset and creates a slight lip or overhang on lower side of combustion chamber and could cause a place to have a carbon build up or possible head gasket issue. will work this problem this week on checking head gskt sealing. Never ran into this problem before!!!! both heads are having the same problem. Not sure if I can work guides that center heads to block? many factors come into play like possible pushrod issues and valvetrain issues. very interesting problem!! gonna have to consult with mpgheads/scott if ever ran into this problem. To me this is preventing a detonation situation by centering the combustion chamber up properly in bore. thanks for checkin in and all the info, good stuff and your efforts are appreciated.
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wyoming4x4
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« Reply #25 on: February 06, 2011, 09:48:58 pm »

ZF tranny. 5s-42 manual trans 4wd to 460/400. overdrive tranny. On this application to a 400 the input shaft is to short. Have to modify the pilot bushing to help give support. It only set about a 1/8" in factory pilot bushing at most. So I had my friend build a pilot bushing that extends out 1/2" longer.  1.050 is actual thickness is what we are doing. The 460 input shaft is a 1 1/4" dia in a zf and small block is 1"1/16 so clutch inputs are different. I'm looking at a centerforce clutch dual friction rated for around 550ftlb tq. should be some overkill for my appliction in towing application. On the flywheel will be shimming the flywheel out .500" to compensate for starter application. gonna confirm this this week on starter. I have a 400 ford bolted up to zf tranny and forgot to check starter last weekend. so will use a center out of another flywheel and machine perfectly flat and will be my shim for possible starter issue and clutch issues to pilot bushing. hope this helps out and catch you later.
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Brian S
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« Reply #26 on: February 06, 2011, 11:01:34 pm »

If I understand what you're saying about the heads, it may be unavoidable. The head gaskets are already larger than the bore so there will be about a .035 step past the bore with a 4.1" gasket. Try a gasket held up to the head to see what it looks like. They make .015-.030 offset head dowels for some applications, I just don't recall seeing any for Ford applications.

Moving the heads around like you're saying may require modifying the intake or spacers to make them fit again. Are the cylinders notched for valve clearance? 

What material is the pilot bushing made from? The extended bronze ones tend to work themselves out the back of the crank over time.

Shimming the flywheel is another thing I'd be cautious about, especially .500" thickness. I don't think iron or mild steel is really strong enough unless it's been hardened after it's machined and it has to be made near perfect so it doesn't throw the balance or alignment off.

I'd avoid doing it if at all possible.
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wyoming4x4
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« Reply #27 on: February 07, 2011, 11:43:42 am »

 On the cylinder to combustion chamber. bolted up without head gskt, just a mock up. On the intake stuff I'm running a 351 cleveland air gap intake. price motorsports intake adapter for the 400 to 351 cleveland. So if any problems will mill the spacer plate if necessary. to be determined type situation. This little project has turned into a little more involved than planned but will be completed either way. This little step is a little more than should be. something will have to be done to atleast help the situation a little. My blessing is a curse just leave things alone is sometimes the best policy but I just have to know everthing in my projects.
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wyoming4x4
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« Reply #28 on: February 07, 2011, 11:55:21 am »

 Spoke with my cam guy mpg heads/scott this morning. Said with my manual tranny situation should be good and he kinda knows how I run my engines. If running a automatic the cam would of been cut different. 88 octane to 91 octane motor with manual tranny and high elevation application. On the elevation only gaining 5% is sometimes a blessing. if you have never ran in high elevation and needed everything you can get I'll take the little 5%. One of the places I hunt is at 9000+ elevation and have to haul trailor 4wheeler and several other pieces of equipment. running 7% grades and some places even steeper. not your everyday application but during hunting season this is my norm and extreme situation that I'm building to. Used to live in houston tx area and making power was easy now I'm here. Basically if you want 400hrspwr motor you build a 500hrspwr motor or forced induction to compensate for elevation at the 5000' give or take. Gonna have to get up to speed on some of these new calculators and I'm familar with the wallis racing stuff cool site just recently found and more info than you can shake a stick at. thanks brian!
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BirdMan
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« Reply #29 on: February 07, 2011, 06:39:11 pm »

In the past I have made some aluminum offset dowels to position heads better/centered on block.  You might have to redrill/endmill offset in bolt holes??  I am attaching a picture of one in a new head I plan on using to position it better.


* MOW 18 deg 225 4.jpg (57.95 KB, 640x480 - viewed 424 times.)
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