Higher HP higher boost HG/timing belts

[assault187]

Its looking like I have to replace my head gasket so I wanted to get some input on what most would recomend.

Since about 1 year 2 months ago I used the Mistu metal HG on a brand new machined block and a good newly decked head with ARP studs. Didnt last too long so I was looking at other makes and noticed there are a few more out now that claim BEST. The car runs 29-30 psi

My choices....
(1) Cometic
(2) Power extreme (looks promising)
(3) mitsu composite
(4) another Mistu metal
(5) HKS metal (Also looks promising)

By the way I will be using another decked head, and of coarse the ARP's

Now Im not sure how to determine what thickness to use on the Head gasket..... what thickness are you guys running with the moderate to high boost applications 28-35 psi, 50+ lbs/min, 8.5.1 compression pistons, 2.0L?

Also when I threw my new cams in and redid my timing belt it seemed as if it had streatched slightly...This was a brand new Mitsu OEM timing belt with maybe 6,000 miles on it so I'll be looking to replace that as well with something maybe a bit stronger...any ideas, HKS maybe?

 

[stephenz]

felpro mls headgasket.its kinda expensive $200 ish,its black with a sticky coating and orings on it.Im running on on my car with boost ranging from 38-56 psi!the good thing about this gasket any auto store that sell fel-pro can special order this gasket. Unlike other MLS head gaskets, Fel-Pro PermaTorqueMLS gaskets feature a proprietary aftermarket coating that accommodates a wider range of surface finishes than do other MLS gaskets. The PermaTorqueMLS design also allows for lateral and vertical motion of the cylinder head - caused by combustion pressures and extreme temperatures - without compromising sealing performance.

good luck
p/n 1153-1


stephen.

 

[dsmfa9nutter]

Cometic IMO.

 

[Kevin Jewer]

At up to 30 psi I had fantastic luck with the stock composite gasket and ARPs. Very forgiving of just about any surface quality on the head and block. I had similar success with the Mitsu metal gasket, and the stock metal gasket on the EVO worked beatifully at 30 psi with a 75 shot even when it went lean and knocked. I recently installed the Felpro metal gasket in the RWD but haven't put any boost to it yet.

I feel that proper installation is more important than actual gasket selection. In most cases, any of the above gaskets will work well at 30 psi, but if installed incorrectly, none of them will last. There is some more info on my site that I posted after learning some hard lessons.

Timing belts will stretch, it's normal. I've checked intervals as short as 1k miles and found measurable stretch. In fact I think it's about done stretching around 1-2k miles after install. I set the tensioner gap to the tight end of the range (.15) and it ends up just right after the belt stretches.

 

[assault187]

At up to 30 psi I had fantastic luck with the stock composite gasket and ARPs. Very forgiving of just about any surface quality on the head and block. I had similar success with the Mitsu metal gasket, and the stock metal gasket on the EVO worked beatifully at 30 psi with a 75 shot even when it went lean and knocked. I recently installed the Felpro metal gasket in the RWD but haven't put any boost to it yet.

I feel that proper installation is more important than actual gasket selection. In most cases, any of the above gaskets will work well at 30 psi, but if installed incorrectly, none of them will last. There is some more info on my site that I posted after learning some hard lessons.

Timing belts will stretch, it's normal. I've checked intervals as short as 1k miles and found measurable stretch. In fact I think it's about done stretching around 1-2k miles after install. I set the tensioner gap to the tight end of the range (.15) and it ends up just right after the belt stretches.

Information noted! I think the HG failed after a overheat I had while tuning with a few hard 3rd gear pulls, The t-stat failed to open...Im sure it caused some distortion in the head/ head gasket. I will be checking the ARP's for stretch, having the new head resurfaced/decked, and checking the block as well to be on the safe side. I also posted this on my local dsm forum and so far I have seen alot of good responses on the Fel-Pro 1153-1 as STEPHENZ stated.

 

[Kevin Jewer]

That felpro gasket is nasty. From the little I know about different HG designs, it seems like a sweet unit. Did you measure your ARPs before install to determine stretch? I was checking them for a while, the lengths are differ a bit. I gave up after a while, since they're cheap enough to throw out after a couple reuses. The A1s cost 3-4 times as much, but if those stretch on me I quit...

 

[diambo4life]

OEM composite or the Mitsu. MLS HG with GOOD head studs will work for 98% of the people on here if you know what you are doing.

 

[assault187]

OEM composite or the Mitsu. MLS HG with GOOD head studs will work for 98% of the people on here if you know what you are doing.

well...with ARP's torqued and re-torqued and 30psi, it still managed to push coolant and this is with a decked block and head! so i'm going to disagree here


I went with the FEL-PRO layered MLS race gasket, This thing is CHAMP! I've been rolling around @ 37 psi and it holds great! and thats Daily....

 

[Kevin Jewer]

The stock gasket will work at over 30 psi, but you have to be serious about making it happen. Naturally the Felpro is better, it's probably the best option we have right now. But it costs 5 times what the stock one does.

 

[assault187]

The stock gasket will work at over 30 psi, but you have to be serious about making it happen. Naturally the Felpro is better, it's probably the best option we have right now. But it costs 5 times what the stock one does.

Good point, The stock composite will run well for a while but if your serious about making power and keeping it that way the extra money will go a loooong way! I think of it as preventitive maintinence, If your going to do it, do it once, do it rite. Plus...the peace of mind is priceless

 

[Hal]

The choice of stud is more important in high boost applications than the choice of gasket.

 

[02HtownSubie]

The stock gasket will work at over 30 psi, but you have to be serious about making it happen. Naturally the Felpro is better, it's probably the best option we have right now. But it costs 5 times what the stock one does.

+1 for the stock gasket. combine with ARP's

 

[90laserRSfwd]

look into o-ringing your block / head at those boost levels.

 

[JessGST]

look into o-ringing your block / head at those boost levels.

Or dish out the money for a set of L19's.

 

[slipstream808]

Where would you find a set of the L19's?

 

[assault187]

Where would you find a set of the L19's?

Anywhere that sells ARP products...

 

[Freerevving]

what are L19's?

 

[blacktalonman]

The L19s are a better head stud than the normal arp studs. They have a higher stretch tolerance.

 

[Freerevving]

so are they stretch studs? or are they made for more ft*lbs?

How much more do they cost?

 

[cbrfrenzie]

Quite a bit more:
ARP Extreme Duty Head Studs (6 Bolt DSM) - Modern Automotive Performance

 

[Freerevving]

whoah those look awesome... too rich for my blood... well, I wish I could justify buying them

Thanks

 

[dsm-onster]

There's no real justification when ARPs and a composite have gone over 500whp for many daily drivers for long periods of time

 

[Freerevving]

There's no real justification when ARPs and a composite have gone over 500whp for many daily drivers for long periods of time

Yeah I realize they are far beyond what I need... but I just love having fine crafted metals like that.... to me it's jewelry... But I'm not stupid enough to by them for that reason

500WHP? Wow that's around 590 bhp! On a composite gasket? Amazing, I wouldn't think the composite gasket could handle that much heat cycling for more than 50k miles... how long did they go?

 

[dsm-onster]

Drive train loss is not the same percentage at higher horsepower as at stock horsepower. It takes the same amount of energy to freewheel a drivetrain to 7500rpms no matter what horsepower you're engine has. 500whp is about 540crank HP. Still respectable for a stock headgasket. Many drive them weekly.

 

[Freerevving]

Drive train loss is not the same percentage at higher horsepower as at stock horsepower. It takes the same amount of energy to freewheel a drivetrain to 7500rpms no matter what horsepower you're engine has. 500whp is about 540crank HP. Still respectable for a stock headgasket. Many drive them weekly.

Drive train loss is a co-effiecient of friction. It is always a percentage, even if the percentage decreases with power/speed.

It's a myth that the transmission steals 40hp no matter what the power. It's like wind resistance, the resistance increases as the speed is increased.

15% drivetrain loss is modest for and AWD system... I would expect about 18% at stock levels. Sorry I forget some people have FWD

Drive train loss is not the same percentage at higher horsepower as at stock horsepower.

that part is true

It takes the same amount of energy to freewheel a drivetrain to 7500rpms no matter what horsepower you're engine has.

that part is untrue because of the rate of acceleration

540 or 590hp on a 4 cylinder creates a lot of peaks in temperature and a lot of thermal expansion... and high mileage has many many heat cycles. I'm just curious to know about how many miles these head gaskets sealed?