Thicker head gasket and more boost ?

[Rudbari]

This is my 1st post and thread here

I read somewhere that with thicker head gasket and use stronger head bolts we can increase the boost up ( like from 10 psi to 14 psi ) is this possible . Don’t know about reliability as well .

[Rudbari]

Anyone with good engine knowledge

[heinzboehmer]

Thicker head gaskets are usually used to lower compression. Generally, higher compression engines do worse with boost, so lowering the compression may allow you to run more boost.

And that's about where my FI knowledge ends. Hopefully someone with more FI knowledge can fill in the rest. Maybe try asking in the e46 Forced Induction subforum?

[Robert's_BMW]

This is my 1st post and thread here

I read somewhere that with thicker head gasket and use stronger head bolts we can increase the boost up ( like from 10 psi to 14 psi ) is this possible . Don’t know about reliability as well .

Lowering your compression will help you run more boost; however, using a thicker headgasket will only drop the compression 0.1 - 0.5 max. If you want higher boost (like for a turbo application) then you should look into low compression pistons (8:5:1) and/or shorter connecting rods to reduce the stroke. Pistons would be the easiest. Like it was said earlier, our engine has a higher 11:5:1 CR and you should only use around 10ish psi of boost (max) if you want to still maintain some sort of reliability in your engine. With that being said, some MaximumPSI kits can make 700+ hp at 20 psi on stock internals. How long those motors last though, who knows.

[Arith2]

When boosting an engine, you have to remember that everything will get stressed more and operate at even higher temps. While the characteristics of stock parts may be fine at a certain temp, with more pressure, you increase temperature. That's how your A/c system works too

Our engine is really tough, let me start off by saying that, but the boost is just going to wreak havoc on an NA high compression engine no matter the headgasket. Our rods and pistons are cast so their plasticity is crap compared to forged components. The crank is forged but for cost and reliability reasons, pistons and rods are not. They will slowly bend over time and not return to original shape. Forged parts are superior in this aspect because of the silicone they add to the metal and the way they are formed. The molecules are lined up much better while cast has random weak points and inconsistencies. I might add that the cylinder also melts on the surface during a power stroke to that will cause problems and can destroy rings or pistons. NA and low boost really won't reveal these but you ask 500-600hp out this design, good luck on reliability. Where NA is superior to boost is the fact that your are freeing up lost horsepower. Force induction is forcing more efficiency into an engine designed to work at 1 bar with like 90% volumetric efficiency(on the best day). Boost will cause it to go higher than 100% which causes stress exponentially. I don't want you to have a blown motor, because I've been there and it sucks.

[Ruley]

MaxPSI went 800ish HP before bending factory connecting rods. Don’t know how much PSI or specifics though.

[Rudbari]

Lowering your compression will help you run more boost; however, using a thicker headgasket will only drop the compression 0.1 - 0.5 max. If you want higher boost (like for a turbo application) then you should look into low compression pistons (8:5:1) and/or shorter connecting rods to reduce the stroke. Pistons would be the easiest. Like it was said earlier, our engine has a higher 11:5:1 CR and you should only use around 10ish psi of boost (max) if you want to still maintain some sort of reliability in your engine. With that being said, some MaximumPSI kits can make 700+ hp at 20 psi on stock internals. How long those motors last though, who knows.

i got ess vt2-575 kit with methanols 10psi in stock engine . I was thinking to rise the boost to 14 psi only with thicker head gasket but it’s seems reliability is the issue with thicker head gasket.

[Rudbari]

When boosting an engine, you have to remember that everything will get stressed more and operate at even higher temps. While the characteristics of stock parts may be fine at a certain temp, with more pressure, you increase temperature. That's how your A/c system works too

Our engine is really tough, let me start off by saying that, but the boost is just going to wreak havoc on an NA high compression engine no matter the headgasket. Our rods and pistons are cast so their plasticity is crap compared to forged components. The crank is forged but for cost and reliability reasons, pistons and rods are not. They will slowly bend over time and not return to original shape. Forged parts are superior in this aspect because of the silicone they add to the metal and the way they are formed. The molecules are lined up much better while cast has random weak points and inconsistencies. I might add that the cylinder also melts on the surface during a power stroke to that will cause problems and can destroy rings or pistons. NA and low boost really won't reveal these but you ask 500-600hp out this design, good luck on reliability. Where NA is superior to boost is the fact that your are freeing up lost horsepower. Force induction is forcing more efficiency into an engine designed to work at 1 bar with like 90% volumetric efficiency(on the best day). Boost will cause it to go higher than 100% which causes stress exponentially. I don't want you to have a blown motor, because I've been there and it sucks.

Agreed it sucks to have blown engine 😜 specially I made 545whp with ess kit and methanols so no reason to go higher with thicker head gasket and have issues with reliability.

[Rudbari]

MaxPSI went 800ish HP before bending factory connecting rods. Don’t know how much PSI or specifics though.

Not interested in turbo charged system

[Arith2]

Agreed it sucks to have blown engine 😜 specially I made 545whp with ess kit and methanols so no reason to go higher with thicker head gasket and have issues with reliability.

This engine is able to make up to around 600hp "reliably" for doubling an engine's horsepower but you go from a 300k engine so exploiting whatever abuse or defects it previously suffered. Then it's just a mystery. Our blocks and cranks can handle that power with like it's nothing. How many miles did you run that set up?

[bigjae46]

A thicker head gasket is commonly used to lower compression.

When I blew my supercharged M54 again I was talking to a guy who builds motors for dune buggies. High HP, turbocharged and runs at redline for hours. He said a thicker head gasket while it lowers compression actually increases detonation.

Unspent fuel in the combustion chamber is cooled by the cylinder walls, head, and piston. If you add a thicker HG then you decrease the cooling effect. Then the unspent fuel detonates. Then tuners will add fuel because there is detonation which actually causes more detonation. You have to maintain a certain piston to valve clearance...then my eyes started rolling into the back of my head.

He’s the only guy that I’ve ever talked to that goes against this common practice but it makes sense to me.

[Robert's_BMW]

i got ess vt2-575 kit with methanols 10psi in stock engine . I was thinking to rise the boost to 14 psi only with thicker head gasket but it’s seems reliability is the issue with thicker head gasket.

If you are supercharged with meth, you could raise the boost a little just because of the meth (which I think you did already if you are making 545 whp). It cools the intake air effectively lowering the chance of detonation as well as the small increase in octane from the methanol mix helps lower detonation. All of this will allow you to advance the timing a little bit more. However, with that being said, your tune should be methanol independent because if its dependent and you run out of methanol or something in the methanol kit breaks, you will most likely cause a lot more detonations and wreck your engine.

[Rudbari]

If you are supercharged with meth, you could raise the boost a little just because of the meth (which I think you did already if you are making 545 whp). It cools the intake air effectively lowering the chance of detonation as well as the small increase in octane from the methanol mix helps lower detonation. All of this will allow you to advance the timing a little bit more. However, with that being said, your tune should be methanol independent because if its dependent and you run out of methanol or something in the methanol kit breaks, you will most likely cause a lot more detonations and wreck your engine.

I made 545whp at 10psi on stock engine and my methanols is independent on 98ron fuel .

ess vt2-575 kit

[Rudbari]

A thicker head gasket is commonly used to lower compression.

When I blew my supercharged M54 again I was talking to a guy who builds motors for dune buggies. High HP, turbocharged and runs at redline for hours. He said a thicker head gasket while it lowers compression actually increases detonation.

Unspent fuel in the combustion chamber is cooled by the cylinder walls, head, and piston. If you add a thicker HG then you decrease the cooling effect. Then the unspent fuel detonates. Then tuners will add fuel because there is detonation which actually causes more detonation. You have to maintain a certain piston to valve clearance...then my eyes started rolling into the back of my head.

He’s the only guy that I’ve ever talked to that goes against this common practice but it makes sense to me.

I was told is common used as well but I only could increase max to 14 psi with some work at head and thick gasket .

[Rudbari]

This engine is able to make up to around 600hp "reliably" for doubling an engine's horsepower but you go from a 300k engine so exploiting whatever abuse or defects it previously suffered. Then it's just a mystery. Our blocks and cranks can handle that power with like it's nothing. How many miles did you run that set up?

At 95k now but if I wanna do it I will get low mileage engine and experiment . But I am not sure