HomemadeTurbo - DIY Turbo Forum

HomemadeTurbo - DIY Turbo Forum (https://www.homemadeturbo.com/)
-   Forced Induction (https://www.homemadeturbo.com/forced-induction-7/)
-   -   thick headgasket? (https://www.homemadeturbo.com/forced-induction-7/thick-headgasket-49736/)

boosted_b16 11-09-2005 02:18 PM

thick headgasket?
 
so i REALLY want to build the bottom end of my b16 so i can actually run a good amount of boost ( 8 psi now) like 12-14 psi, but i just dont have the damn money, so how reliable would it be if just threw on a thick ass head gasket to lower the c/r down to like 9.2:1 ? obviously it wouldnt be as good as building the bottom end, im just wondering if it would be worth it at all? worth it to me would be if it lasted as long with the thick head gasket on like 12+ psi, as it would last stock on 8 psi, do you think that would happen? im just worried that i will still shatter my ring lands, any comments are appreciated!

HMTguy 11-09-2005 02:21 PM

Re: thick headgasket?
 
I wouldn't even bother. With the lower compression you'll have to run more psi just to get the same power you were making at a lower psi before with the higher compression.

boosted_b16 11-09-2005 02:35 PM

Re: thick headgasket?
 
so a 9:1 c/r b16 on 12-14 psi will only make the same power as a 10:1 c/r b16 on 8 psi with the same turbo? i wouldnt think thats true.....maybe im wrong but i would think the first one i listed would make more power. ???

JeenYus 11-09-2005 02:38 PM

Re: thick headgasket?
 

Originally Posted by boosted_b16
so a 9:1 c/r b16 on 12-14 psi will only make the same power as a 10:1 c/r b16 on 8 psi with the same turbo? i wouldnt think thats true.....maybe im wrong but i would think the first one i listed would make more power. ???

i don't think that's true either...I've been thinking about doing the same thing since i don't have the funds to build my bottom end either, but have been worring about future consequences...

Loserkidwac 11-09-2005 03:41 PM

Re: thick headgasket?
 
I remeber seeing a dyno for a ls teg with i think an sc61 and only a cosmetic head gasket (almost stock motor) tuned by neptune hitting around 290whp with like 18psi...

However lowering compression just makes it a little safer to run more boost but more boost with lower compression dosen't always mean more power...It will mainly depend on who and how well the car gets tuned, I think i'd rather invest the money somewhere else personally

youdontknowmeee 11-09-2005 04:05 PM

Re: thick headgasket?
 
cometic head gaskets help a lot ive heard

HMTguy 11-09-2005 04:09 PM

Re: thick headgasket?
 

Originally Posted by boosted_b16
so a 9:1 c/r b16 on 12-14 psi will only make the same power as a 10:1 c/r b16 on 8 psi with the same turbo? i wouldnt think thats true.....maybe im wrong but i would think the first one i listed would make more power. ???

That's not what I said, but you will still have to run more psi to make the same hp.

mizter_2 11-11-2005 02:24 PM

Re: thick headgasket?
 
if u want more power you gottta up the C/r...

sohcpwr 11-11-2005 02:51 PM

Re: thick headgasket?
 
as long as you keep away from detonation, the thick head gasket will definately allow you to run more boost. however, with more boost comes the possible chance of detonation, and since the gasket is thicker, more of it is exposed. its kind of a double edged sword. damn b series

Reddy 11-11-2005 05:15 PM

Re: thick headgasket?
 

Originally Posted by mizter_2
if u want more power you gottta up the C/r...


Yeah only up the dynamic compression not the static compression ;)

mycrx 11-11-2005 06:59 PM

Re: thick headgasket?
 

Originally Posted by Loserkidwac
I remeber seeing a dyno for a ls teg with i think an sc61 and only a cosmetic head gasket (almost stock motor) tuned by neptune hitting around 290whp with like 18psi...

However lowering compression just makes it a little safer to run more boost but more boost with lower compression dosen't always mean more power...It will mainly depend on who and how well the car gets tuned, I think i'd rather invest the money somewhere else personally

is it just me or should 18psi on a sc61 put out more then that.

baldur 11-11-2005 07:29 PM

Re: thick headgasket?
 

Originally Posted by jagojon3
I wouldn't even bother. With the lower compression you'll have to run more psi just to get the same power you were making at a lower psi before with the higher compression.

Given that your engine runs with the ideal peak pressure point and no detonation under all circumstances and the airflow is the same, the power lost by going from 10:1 to 8:1 is 6.175%
But, if your engine doesn't have the fuel required to run at the optimum peak pressure point... then your efficiency is out the window.

If you go from 10 to 9 the theoretical drop in efficiency is 2.847%
If you go from 10 to 7.5 the theoretical drop in efficiency is 8.066%
Go from 10:1 to 14:1 and gain 8.329%

Bottom line is, run the compression ratio as high as you can get away with using the fuel you have. This means the engine running at the ideal peak pressure point at all revs and no detonation. Run the compression ratio too high and you have to get a better fuel or sacrifice the efficiency gained in running high compression ratio by running unoptimal spark timing.

granth91 11-12-2005 06:08 AM

Re: thick headgasket?
 

Originally Posted by mycrx

Originally Posted by Loserkidwac
I remeber seeing a dyno for a ls teg with i think an sc61 and only a cosmetic head gasket (almost stock motor) tuned by neptune hitting around 290whp with like 18psi...

However lowering compression just makes it a little safer to run more boost but more boost with lower compression dosen't always mean more power...It will mainly depend on who and how well the car gets tuned, I think i'd rather invest the money somewhere else personally

is it just me or should 18psi on a sc61 put out more then that.

I'd say so. My tuner made 303whp on 16psi with a .57 trim t3/t4 on stock block LS

B16CRXT 11-12-2005 09:35 AM

Re: thick headgasket?
 
i ran 12 psi with a .48/.60 just fine. You should be really good with that big ass intercooler. mine is tiny. my compression is low in cylinder 1 now----> Shoulda spent teh extra money on pcv system/catch can. :'(

Loserkidwac 11-12-2005 10:00 PM

Re: thick headgasket?
 

Originally Posted by granth91

Originally Posted by mycrx

Originally Posted by Loserkidwac
I remeber seeing a dyno for a ls teg with i think an sc61 and only a cosmetic head gasket (almost stock motor) tuned by neptune hitting around 290whp with like 18psi...

However lowering compression just makes it a little safer to run more boost but more boost with lower compression dosen't always mean more power...It will mainly depend on who and how well the car gets tuned, I think i'd rather invest the money somewhere else personally

is it just me or should 18psi on a sc61 put out more then that.

I'd say so. My tuner made 303whp on 16psi with a .57 trim t3/t4 on stock block LS

It might have been more I don't really remeber but he was around 300whp on a stock block

Found the link it was 15psi on pump gas, my bad but still impressive look at some of ther other dynos there some of them are awesome

http://forums.evans-tuning.com/viewtopic.php?t=2489

AMkrew 11-13-2005 11:17 PM

Re: thick headgasket?
 
Something I was reading the other day: When you have a motor that is very resistant to detonation, like hondas, this is done by the way the combustion chamber is shaped when the piston is at tdc. Within 30 degrees btdc, usually, the fire time starts and the flame front begins. This flame travels around the chamber and burns quicker out in the open (the pentroof style chamber has most of the volume dead center in the chamber), and slower in the confined areas (like on the quench pad areas on the intake and exhaust sides of the chamber).

Now quench, as it was explained to me, is when the piston comes uber close to the combustion chamber roof(reccomended static quench distance is .040" for most applications), and "squishes" turbulent a/f mixture toward the open areas. This ALWAYS has good results. The turbulence, somehow, has a great affect on the travel of the flame during combustion, and also has a cooling effect on the quench area, thereby cooling the chamber(take THAT, detonation). I must say, though, that the honda clearances are most likely nowhere near this (haven't actually been able to measure it yet) and we could potentially have a greater resistance to detonation if this was implemented in a motor.

When a thicker head gasket is used, the "quench" areas on either side of the chamber are ------ further apart at tdc, thereby negating the affects of the "close collision" of the slug to the chamber. The moral of the story is that yes, you may be able to run more boost, but your power output may be lower than you could have while bennefitting from these quench pads, due to the timing issue. Efficiency to resist detonation is lost when the quench is eliminated, as baldur said(i think ;D).

BTW I think I was reading a silvolite/Keith Black piston installation instruction manual from the SBC I'm putting together at work. That thing had some seemingly good info! Also, My boss said that this info might not be pertenent to turbo'd hondas :S :1

-josh-


All times are GMT -5. The time now is 10:29 AM.


© 2024 MH Sub I, LLC dba Internet Brands