Using a thicker head gasket to decrease compression

[Strictly Attitude]

Is this safe to do I have been looking into adding a single turbo only cause I can't afford twins or compound turbo but would like to get my compression down a little more is a thicker gasket feasible. If not what are my options?

 

[grumpyvette]

a common question, and Id point out that getting quench distance in the ideal range to reduce detonation has been a very LOW priority on most OEM stock engine combos ,(thats not saying it won,t help, but it might not be critical in all combos) so what your asking is hardly a new concept or something thats not being done regularly.
one of my friends in the neighborhood built a 454 BBC on which he installed a 871 roots supercharger and .062 copper head gaskets too get a bit lower effective compression,(he was trying to get below 8.5:1) and while it increased the quench to nearly .080 which is hardly ideal, hes been running it that way for a few years now!
he has large rectangle port aluminum heads, and he runs the fuel air mix rich and watches his ignition timing advance curve and has done that for several years without issue so Id have to concede it works in some applications

http://garage.grumpysperformance.co...-octane-for-compression-ratio.2718/#post-7057

http://www.jegs.com/p/SCE-Gaskets/SCE-T ... 5/10002/-1



http://airflowresearch.com/articles/art ... A21-P1.htm

viewtopic.php?f=50&t=50&p=59&hilit=copper+head+gasket#p59

viewtopic.php?f=44&t=937&p=1578&hilit=copper+head+gasket#p1578

HERES A SET OF COPPER HEAD GASKETS TO USE ON A 383SBC with a ZERO DECK and the piston sticking .015 above the deck,to get a .047 quench
http://www.jegs.com/i/SCE-Gaskets/829/T ... tId=753475

Head Gasket Roughness (ra)

I've installed my heads now, getting ready for when the headers come back. I noticed the surface finish of the aluminum heads, they seemed to be very rough. But what is rough, how do you quantify roughness ??? Try telling your buddy what you mean when you say "it was very rough". The most...

garage.grumpysperformance.com

http://garage.grumpysperformance.com/index.php?threads/sbc-head-gasket-choice.11070/#post-79067

http://garage.grumpysperformance.com/index.php?threads/head-gasket-related.1859/#post-50617

http://garage.grumpysperformance.com/index.php?threads/head-gasket.10085/#post-39429

http://garage.grumpysperformance.co...ad-gasket-for-aluminum-heads.4403/#post-26317

http://garage.grumpysperformance.co...asket-bore-size-vs-bore-size.2681/#post-11603

yeah! the gaskets linked above ARE expensive and yeah I'd call SCE before ordering them, but they seem to be a perfect choice, and they are darn good gaskets
1-661-728-9200
Ive used COPPER HEAD GASKETS FOR DECADES WITH ZERO FAILURES


yeah! Ive been using the solid copper gaskets in the correct thickness for each application that state they require O-rings, and NOT using o-rings but simply spray both sides to well coat the head gasket then installing them damp and torquing down the heads, NO NOT what the manufacturer suggests but its worked without issue for decades. I picked up that bad habit because this types CLEAN AND REUSE, and most of my mentors did it without issues well before I started racing
http://www.summitracing.com/parts/sum-111502/overview/

 

[Strictly Attitude]

reading time see ya in a few hours. See that is the thing if adding more gasket is going to be counter productive to detonation which would be why I would want to drop compression is it worth it? I will read just thoughts in my head going into it. Also is there any way to get a sbc gen 1 to spray oil to cool the pistons?

 

[philly]

reading time see ya in a few hours. See that is the thing if adding more gasket is going to be counter productive to detonation which would be why I would want to drop compression is it worth it? I will read just thoughts in my head going into it. Also is there any way to get a sbc gen 1 to spray oil to cool the pistons?

if you have an open chamber or a dished piston or both then yea use a thicker gasket... if you have a modern chamber/ piston design then i would worry more about precise ignition control and getting that combustion heat away from the chamber ASAP through better cooling

 

[grumpyvette]

reading time see ya in a few hours. See that is the thing if adding more gasket is going to be counter productive to detonation which would be why I would want to drop compression is it worth it? I will read just thoughts in my head going into it. Also is there any way to get a sbc gen 1 to spray oil to cool the pistons?

yes there is several ways to reduce the tendency toward detonation , and yes you can add oil spray to cool pistons and water/methanol injection to greatly reduce combustion temps.

 

[Indycars]

yes there is several ways to reduce the tendency toward detonation , and yes you can add oil spray to cool pistons and water/methanol injection to greatly reduce combustion temps.

Is it possible to determine thru combustion chamber/piston observation which
one/both is causing the detonation. Then spending money where you get the
biggest bang for the buck???

 

[grumpyvette]

methanol/water injection would be more effective

 

[Strictly Attitude]

reading time see ya in a few hours. See that is the thing if adding more gasket is going to be counter productive to detonation which would be why I would want to drop compression is it worth it? I will read just thoughts in my head going into it. Also is there any way to get a sbc gen 1 to spray oil to cool the pistons?

yes there is several ways to reduce the tendency toward detonation , and yes you can add oil spray to cool pistons and water/methanol injection to greatly reduce combustion temps.

How do you add oil spray? I know it is one way and water/methanol is another good way to keep cylinder temps down. I would like to maximize what I can to be able to run as much safe boost as possible. I am planning on running a pretty big turbo that is less resistant on the exhaust that will allow me to keep my cam and will hit boost right around 3800 and act like I just hit a 300 shot of NO2. Gonna probably need a new dust pan to pick up my drive train. But this is still at least one year out. EFI comes first. But exploring and planning comes now.

 

[grumpyvette]

these guys sell a kit with a jig to retro=install oil spray jets on the common engines

BlackoutSteve posted these pictures
What cylinder head?
With my 4.280" bore and AFR head, I am forced to use a 4.540" bore gasket because the chambers are wide and would otherwise allow the gasket to "hang" in the chamber.

For example..

MLR400-010 Piston Dome Oiler Kit /SB GM 350 Mains
MLR400-100 Piston Dome Oiler Kit/BB GM 454 Mains
MLR400-000 Piston Dome Oiler Kit /SB GM 283 Mains
MLR400-210 Piston Dome Oiler Kit /SB Ford 351 Mains
MLR400-200 Piston Dome Oiler Kit /SB Ford 302 Mains
MLR311-000 Rear 4-port Fitting for Spring Oilers

Each reusable kit includes the following components:

Main bore housing drill fixtures (aluminum)
Eight metering jets for one engine (extra jets also available separately)
1 drill tap with 8-32 thread
1 tap 8-32 thread
1 6-inch #28 drill

http://hotrodenginetech.com/pin-oiler-prep/
viewtopic.php?f=54&t=8463&p=29691&hilit=Pin+7lg1#p29691
yes I know, I hear it all the time, Why bother, "if those piston oil spray gizmos really helped the factory would have installed them"

well NEWS FLASH! the new corvette engines come with them installed from the factory!

these little oil spray jets tend to reduce the chances of detonation destroying rings and pistons by reducing the piston operating temps, by constantly bathing the lower piston in oil, which tends to be more than 100F or more lower in temp than the piston runs without the oil spray cooling it. this requires re-routing some oil to jets you install in the block to allow some oil going to the main bearings to flow to the squirters to enhance piston cooling, normally oil thrown from the rod bearings keeps the rings lubed but the squirters do a more consistent job on the pistons
READ RELATED LINKS

viewtopic.php?f=57&t=4701&p=19139&hilit=+coating+pistons#p19139

http://hotrodenginetech.com/pin-oiler-prep/

related threads

viewtopic.php?f=53&t=4516&p=16279&hilit=+coating+pistons#p16279

viewtopic.php?f=52&t=6491&p=20681&hilit=spray+springs+cooling#p20681

viewtopic.php?f=54&t=64

viewtopic.php?f=54&t=64

viewtopic.php?f=57&t=176&p=210&hilit=oil+cooler#p210

viewtopic.php?f=54&t=2187

heres a few pictures of modifying a big blocks lower end to add oil spray jet coolers to cool the pistons

 

[philly]

take into account that in high rpm applications, oil squirters are reported to cause some windage issues, for us mere mortals that live below 7000rpm i think the benefits outweigh the windage costs... i would wait untill you actually have detonation issues before spending the time and money retrofitting thaminto the block to solve the detonation issues, tho.

ultimately grumpy is right best bang for the buck is a methanol kit.