Can you plan for quench

Strictly Attitude

solid fixture here in the forum
OK here I am looking at my options for a 91-93 octane pump gas streetable. Looking into as many aspects as possible to make things go smooth and end up with what I want in the end. So from my readings quench is good .038-.046 or .044 or .042 depending on which of Grumpy's posts you read lol. Brian likes .039 zero deck with .039 felpro and Grumpy likes to be at .042-.044 ideal. Now how can plan ahead to reach those numbers and have an optimal compression ratio to run on pump gas?

So I know I have a standard deck block which should be 9.025 deck height and I know I will run a crank with a stroke of 3.75" and a rod that 6.0".

What numbers am I looking for in pistons to let me know how far in the whole they should sit?

I realize that the ability to choose a certain thickness head gasket will help hugely here also?

Any insight is apreciated here.
 
There are many variables as You know John.
Most important Piston pin setting or compression height.
Aftermarket manufacturers have Pin settings all over.
Only real way to get what you want is Pre engine mockup and carefull measurements made.
Then have Custom pistons made.
Call JE, ROSS, WIESCO, DIAMOND.
DIAMOND PISTONS MY TOP PICK TO USE.
Now cash is tight for All.
Next best option I have found is Keith Black Hyperuentic pistons.
Excellent listings selection.
All listed but Olds 425 ci V8.
So few of those around but I have one.

Kieth Black lists all required to know.
Figures in .010"-.012" deck milling cleanup cuts. Everyone wants forged pistons. Truth is few drag race really.
Blurping gas pedal and burnout is not drag racing. Just drunk guys screwing around .
 
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I have a set of Keith Blacks I am using in 1 455.
Very Nice.
Only Diamond Forged Better I think.
 
My olds 425 has a factory quench of .032 " only.
.015" down the hole the piston top from deck at TDC.
.017" Inch thick shim head gasket only.
I think its s big factor why they ran so strong .
Need just 87 octane pump gas I am told with full ignition advance.
No retarded timing needed.
 
I hear you there Brian was looking at probe 12337 pistons and my plans are not as much drag racing as hurting the feelings of that m3 or s4 on the curvey road along with some passes at Lebanon valley. All my turbo money is ate up by this disaster so building her stout and putting some spray to her from a kit I have laying around.
 
most guys simply have the block deck milled the minimum required to get it parallel and strait, they buy the type of rotating assembly that should fit , according to the manufacturers specs , with the correct rod piston and crank types selected so the block deck height,matches the rod length and piston pin height, that match the application, and do the required calculations as to combustion chamber vs piston dome volume to get the compression ratio, they want , this places the piston deck height in the range where quench can be adjusted with the head gasket thickness.
Cylinder Pressure Note: youll generally want to try hard to maximize the useable compression as the higher the compression before you get into detonation the more efficiently the fuel can be burnt and the more torque the engine can produce, if limited to pump high test 92-93 octane fuel,165 psi # of cylinder pressure is about the best cylinder pressure for Iron heads with 92-93 octane, using pure un-ethanol laced fuel, gasoline. while the faster heat transfer rate of aluminum cylinder heads will usually allow 190psi # as the upper limit or best for aluminum heads.
compccsguide.png


flowq.png

http://www.enginebuildermag.com/201...ton-compression-height-and-crankshaft-stroke/
deckh.jpg

deckh.png



engbalq5.gif

quenchd1.png

vechart.gif

Cylinder-Pressure-Lrg.gif

CRVariation.png

Compression_Power.gif

ignitiontiming.png

Stoich.gif



lets say the piston deck height averages .011 below the block deck, then you would subtract .011 from .044 and get .033, you would find a .030-.033 head gasket (.032 is very common)


lets say the piston deck height averages .011 above the block deck, then you would add .011 too .044 and get .055, you would find a .050-.052 head gasket

index.php

READ THIS AND SUB LINKS
http://garage.grumpysperformance.com/index.php?threads/cooler-denser-air.8961/#post-54528
bolthread.png

headgasjk.png

p173610.jpg

they measure the piston deck height after the machined block has the rotating assembly test fitted
deckx.jpg

piston down in hole at TDC.jpg

no, if you have any engine and want too find the rure compression you need to deal in verified fact, not assume what the manufacturers suggest is always correct.
you just cc the heads, combustion chamber volume, place the piston 1" down the bore and seal the rings gap around the pistons,
above the rings with moly grease or Vaseline and measure that volume and calculate what a bore diameter cylinder 1" tall would
contain, minus the volume you,ve measured, the piston dome took up.then calculate the true compression.
peanutpl2.jpg



pdome2.jpg

pdome3.jpg

pdome1.jpg


read related linked info

https://www.uempistons.com/index.php?main_page=calculators&type=piston_comp

http://garage.grumpysperformance.co...n-chamber-or-piston-dome-or-port-volume.2077/


http://garage.grumpysperformance.com/index.php?threads/ccing-my-heads.14187/#post-71989

http://garage.grumpysperformance.co...ng-combustion-chambers.2630/page-3#post-77963
yeah! theres long bloody fingernail marks on the pavement showing where I was reluctantly being drug kicking and screaming all the way into the computer age... this was what I was REQUIRED too use in college when I went through engineering classes
versa2.jpg


now I carry a more modern version, so yeah over time I learn too adapt.
tx83plus.jpg

head gaskets are rarely completely round, nore are combustion chambers
you,ll want to place a head gasket you,ll use on the heads and mark the area inside the opening as the only areas you can change,
(notice the gasket fire ring is NOT a perfect circle like many people assume)
ideally you,ll want to un-shroud the valves while opening up the combustion chamber volume,
but not extend the combustion chamber past the front edge of the gasket fire ring,
as that usually causes gasket failure

http://garage.grumpysperformance.com/index.php?threads/ccing-my-heads.14187/

http://garage.grumpysperformance.com/index.php?threads/iron-vs-aluminum-heads.389/#post-31684

http://garage.grumpysperformance.co...r-piston-dome-or-port-volume.2077/#post-60554
before you spend a good deal of money porting and un-shrouding any iron cylinder heads, keep in mind aluminum heads are easily repaired in a skilled and experienced automotive machine shop thats equipped to do those repairs but damaged iron cylinder heads are either much harder to repair or good door stops
http://garage.grumpysperformance.com/index.php?threads/iron-vs-aluminum-heads.389/#post-7266

gasketsh.png

laying a head gasket on the head and use machinist blue dye to show the areas inside the gasket fire-ring
8c3cd11a-b277-4018-b98a-b5648e0314be_1.74e42cf0e55dcba325d8cd403b5783b9.jpeg

http://www.skygeek.com/dymon-8000-s...MI8vPS24jm1gIVBolpCh2pnAoWEAQYAiABEgL2ZPD_BwE

thus the first logical step would be to carefully place a identical head gasket to what you'll use on the engine , properly lined up on the cylinder head and accurately scribe its inside dimensional limits on the cylinder head, a metal scribe , a dremel tool and machinist blue would be helpful here
keep in mind its one of several factors working together, things like getting the quench correct, polishing and un-shrouding the combustion chamber, getting the ignition advance curve and fuel/air ratio correctly matched and taking the time to polish the piston, dome, removing sharp edges from valve clearance notches , and polishing and very slightly rounding sharp edges on the valves, use of the correct spark plug heat range, removing exposed threads in the combustion chamber after you test by inserting a correct spark plug, certainly helps reduce any potential hot spots.
macbl.jpg



you might be amazed at how much material can be removed ,
too noticeably increase air-flow and un-shroud the valves,
and how little it might effectively change,
the combustion chamber volume and compression.


chamberedge1.jpg

chamberedge2.jpg

then buy the required head gasket thickness to allow the quench to fall in that .040-.044 range
http://www.csgnetwork.com/compcalc.html

http://www.gtsparkplugs.com/CompRatioCalc.html

http://www.summitracing.com/expertadviceandnews/calcsandtools/compression-calculator

https://www.rbracing-rsr.com/compstaticcalc.html

http://www.diamondracing.net/tools/


HERES A FEW SBC HEAD GASKETS


stamped steel embossed head gaskets in both coated and un-coated versions in thickness ranges from about .015\.018
copper gaskets .021-.080 in .010 steps with some added extra odd sizes sprinkled in to the mix, and there are head gaskets up to about .120 for some of the more popular engines like the SBC

.028
http://www.summitracing.com/parts/NAL-10105117/



.030
http://www.summitracing.com/parts/cgt-c ... /chevrolet


.032

http://www.summitracing.com/parts/sum-1 ... /chevrolet


.036
http://www.summitracing.com/parts/cgt-c ... /chevrolet



several types
http://www.gmpartsdirect.com/performanc ... D=697.html


.038
http://www.speedwaymotors.com/Super-Sea ... ,1587.html


http://www.ebay.com/itm/Fel-Pro-New-Sma ... 0726964877


a few related and useful threads,
http://garage.grumpysperformance.co...gine-to-match-the-cam-specs.11764/#post-55571

http://garage.grumpysperformance.co...y-in-building-a-good-engine.11682/#post-54682

http://garage.grumpysperformance.com/index.php?threads/finding-a-machine-shop.321/#post-3007

http://garage.grumpysperformance.com/index.php?threads/a-few-calculator-links.7108/#post-27382

http://garage.grumpysperformance.co...on-picking-a-shop-to-do-work.5053/#post-28837

http://garage.grumpysperformance.com/index.php?threads/precision-measuring-tools.1390/#post-52469

http://garage.grumpysperformance.com/index.php?threads/types-of-crankshaft-steel.204/#post-15727

http://garage.grumpysperformance.co...ket-race-not-transportation.14229/#post-72588

http://garage.grumpysperformance.co...in-height-compression-height.5064/#post-66240

http://garage.grumpysperformance.co...ing-parts-and-a-logical-plan.7722/#post-51341

http://garage.grumpysperformance.co...onnecting-rod-rod-length-too-stroke-info.510/

http://garage.grumpysperformance.com/index.php?threads/maximizing-piston-to-bore-ring-seal.3897/

http://garage.grumpysperformance.co...ng-combustion-chambers.2630/page-5#post-82766

http://garage.grumpysperformance.com/index.php?threads/tall-deck-options.14678/#post-79151


 
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Grumpy that's the plan leave what I can. Block dropped off yesterday so hopefully all comes back well. Brian will do more investigating on my pistons been pretty busy with ink lately funding my speed habit!
 
I see why you like diamonds they are really light
I like them because they will make whatever you want.
Excellent reputation .

Using a real light piston is not wanted with nitrous or Turbo Boost.
It must be made real strong. More Meat needed.

Everyones dreams got crashed.
Look around . Use what you can have.
 
Using a strong light piston with meat up top is what you want! Save me pennies and get what I want makes me happier just need to decide what I really want and be realistic (the hard part). Hopefully can sell my forged slugs to offset some of the cost ;)
 
Using a strong light piston with meat up top is what you want! Save me pennies and get what I want makes me happier just need to decide what I really want and be realistic (the hard part). Hopefully can sell my forged slugs to offset some of the cost ;)
Yes be realistic John. I know its hard to do.
Truth is everyone with a Corvette is broke right now.
Guys with money don't Race.
Do your own thing.
Probe pistons are respectable .
Ford 5.0 guys use them on a budget.
Hold up Ok.
 
With the number of 383 motors built today, I'm sure there are plenty standard size
pistons with a compression height of 1.140 inches. Then you adjust the quench
distance with a appropriate size head gasket. Lets assume you are wanting a 0.040"
quench distance (QD) and you mill the deck .010" or block height of 9.015".

The calcs below give a zero deck clearance, therefore the QD is totally dependent of
the gasket thickness of .040"

Compression height = block height - rod length - (0.5 X stroke)
Compression height = 9.015 - 6.00 - (0.5 X 3.75)
Compression height = 1.140"

You could buy a compression height of 1.125(this is what I did), now the piston is down
in the hole .015". Now the QD equals .015 + gasket = .015 + .025 = .040"

I bought Mahle # SBC125125F05 and it has a complete oil ring groove.
http://www.summitracing.com/parts/mle-sbc125125f05

Hope that helps!
 
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I fired up the '63 Grand Prix just a bit ago John. The 403 Olds took off running in just 1 second. Last started it in November 2014.

Battery was hooked up too. .no jump.
Love those Olds Engines like you do .
 
Awesome Brian think I got my combo figured out now will keep you guys in the loop you know me I am not happy with just the average power level why my 355 was fire breathing for what it was well matched parts.;) Surprised and hurt allot of feelings it would shit and get then it would hit 5000rpm and say hold on. Not gonna gain much hp this time around maybe 30 tops but gonna get at least 50ft lbs more out of her.
 
Don't forget about Rear Differential Gearing John.
Probably the single best performance mod to be done with A SBC.

They are building some crazy fast cars today.
Best way I know for least amount of $ is A Big Block.
BBC. Pontiac. Oldsmobile.
 
No replacement for displacement I hear that sucks already deeply invested in sbc still can be stout and avoid embarrassing moments from the fast 4 door sedans and stock normal muscle cars had a c6 vette try to show me he found out quick wasn't stock. Think he was pretty surprised to see the ole 72 on still on his ass.
 
No replacement for displacement I hear that sucks already deeply invested in sbc still can be stout and avoid embarrassing moments from the fast 4 door sedans and stock normal muscle cars had a c6 vette try to show me he found out quick wasn't stock. Think he was pretty surprised to see the ole 72 on still on his ass.
Money is pretty tight for all right now.
We went through a Spew on Digital Corvette Forum recent with a Pro built 406 ci SBC. On the Superflow Engine Dyno it made Killer TORQUE NUMBERS.
Nice HP Too. Cam on soft side tame.
In his C3 Corvette he was unhappy.
Felt slow.
He used different headers than was used on the engine dyno test.
BIG TUBE SCHOENFIELD SUPER LATE MODEL WINGED WARRIOR SPRINT CAR HEADERS WERE USED.
ALL BLAMED HIS Q-JET CARB.
SAME CARB WAS ON THE DYNO. VE NUMBERS 100%
PHOTOGRAPHED PROOF OF ENGINE DYNO.
I SPOTTED BIG TUBE HEADERS WHILE NO ONE ELSE DID.
I ZOOMED IN ....SCHOENFIELD LOGO WELD ON TAG ON THE HEADERS....


The Number 1 reason to go Big Block is easy available $400-500 Big Primary Tube headers. 2" inch primary. 3-1/2 "collectors.
Engine performs exact as predicted of DD2000.
ENGINE DYNO.
IN YOUR CAR.

Sinking lots of money into a SBC Is not worthwhile anymore.
Never perform to expectations.
No big Tube headers can be bought for them to fit Musclecars & Vettes.

Bar has been raised real high now.
10-second Hellcats on the Street for $60,000 cash.
 
Q-jet is an awesome carb allot of guys scared of them but properly tuned they awesome. Dynatech seems have the best fitting good long tube headers for sbc in the chevelle gonna have open 3" on a switch 2.5 on the mufflers got the borlas in they were so much better that the flowmaster 44s. Your late mentor said it right cause after this the only gm left is the block. BBC or pontiac and olds at least you have parts you can reuse. Gotta love it.
 
Money is pretty tight for all right now.
We went through a Spew on Digital Corvette Forum recent with a Pro built 406 ci SBC. On the Superflow Engine Dyno it made Killer TORQUE NUMBERS.
Nice HP Too. Cam on soft side tame.
In his C3 Corvette he was unhappy.
Felt slow.
He used different headers than was used on the engine dyno test.
BIG TUBE SCHOENFIELD SUPER LATE MODEL WINGED WARRIOR SPRINT CAR HEADERS WERE USED.
ALL BLAMED HIS Q-JET CARB.
SAME CARB WAS ON THE DYNO. VE NUMBERS 100%
PHOTOGRAPHED PROOF OF ENGINE DYNO.
I SPOTTED BIG TUBE HEADERS WHILE NO ONE ELSE DID.
I ZOOMED IN ....SCHOENFIELD LOGO WELD ON TAG ON THE HEADERS....


The Number 1 reason to go Big Block is easy available $400-500 Big Primary Tube headers. 2" inch primary. 3-1/2 "collectors.
Engine performs exact as predicted of DD2000.
ENGINE DYNO.
IN YOUR CAR.

Sinking lots of money into a SBC Is not worthwhile anymore.
Never perform to expectations.
No big Tube headers can be bought for them to fit Musclecars & Vettes.

Bar has been raised real high now.
10-second Hellcats on the Street for $60,000 cash.
You know slso as well as I do in 383 with my current setup I will not gain but 2 tenth in quarter mile and with my current tires and diff is a 13 sec car high 12 at best if the stars are in perfect alignment. But with proper posi and a set of slicks would be in the high 11's. 1/8 mile might be different but it's 1/4 mile here. Allot to be made in #1 performance mod tires.
 
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