MY99TAWS6

iTrader: (3)

I see afr shows felpro, and cometic but not gm as gasket choices on their 225 heads that I just received. Thought most everyone runs the gm gaskets now. I am planning to stick to likely 10 to 12 psi 90% of the time with maybe the very odd time going up to 15 or possibly 18psi. I will not ever be going over 18psi. Is the felpro recommended by AFR good enough? Should I get a cometic gasket also mentioned on their site? What about head studs. Are the standard arp good enough or should I splurge for the L19 ones?

Also do normal rockers fit and work on the afr 225s? And what are good rocker studs..arp makes some of those too I would think? I was thinking going with the ls1 scorpion rockers. Think summit now sells them branded to their name in newest catalog.

Drew04GTO

iTrader: (1)

If there's not a huge increase in price between standard head studs and l19 head studs go ahead and get them. Just remember with the more exotic alloys of steel they usually gain tensile strength at the expense of fatigue life and, most importantly, NEVER EVER EVER EVER EVER touch L19 anythings with your bare hands, finger oils (even the smallest ammount) will cause it to be brittle and fail.

Inspector12

iTrader: (29)

Do the L19's and I would just use the new GM 5 layer MLS that is what they are using on the new ZR1's or even a standard MLS gasket will hold what you are wanting to.

CHAMRA1

Just get any MLS Gasket ,

For those heads you will need a minumum 4.120" bore gasket to clear the chambers properly and seal 100%.

I'm using Cometics 4.130" and .051" thick .

MY99TAWS6

iTrader: (3)

Did you spray the cometics like some do or did you put them in dry like cometics recommends.Did you do any special head or surface prep?
What boost level are you running.?
And guys the afr site recommends gm as choice on their 205 heads but not the 225 heads,not sure why exactly..
Anyone try the felpro 1041s..confused if you have to do anything to use them ?
And never heard that about l19 being so touchy.

Any of you 225 guys running stock rockers?

kp

iTrader: (34)

I'm using the 6.2L 5 layer GM MLS on 72cc 225s. So far so good. Some say the bore is a little small on those gaskets but it looked OK to me when I laid them on the heads so I dunno..

I use stock rockers on mine, and the regular ARP studs as well.

CHAMRA1

I always spray hylamar on the cometics .Never had a problem with them .

Cheatin' Chad

iTrader: (3)

I think the extreme concern over "finger oils" is overly cautious and in the case of L19 fasteners incorrect.
What you definitely want to do is make sure they are coated witih motor oil at all times. This is the reason I do not like them for exposed head stud applications.If you have reliable evidence proving otherwise please post here.
Also, I have seen little to no evidence that you give up fatigue life with L19 steel as it is still a steel and has a near infinite fatigue life as long as it's limits are not exceeded. AL for example has a limited fatigue life.

OP: I think L19 headbolts are not only unneccessary in your application they might cause you problems in a DD vehicle. You WILL gain in ultimate clamping force with L19 fasteners under ideal conditions. Do you need it? I doubt it.

Quote from ARP "This material is easily contaminated and subject to stress corrosion. It must be kept well oiled and not exposed to moisture."

ChevyChad

iTrader: (50)

Problem with the 5 layer MLS gaskets is that they are 4.100 bore, and that is exactly the same size as the 'big bore' AFR 225's. I am using LS7 gaskets with my AFR 225's. I had a set of 5 layer 6.2L MLS gaskets I was hoping to use but was advised not to by Tony Mamo so I went the LS7 route instead. This thread may help you out some maybe:

https://ls1tech.com/forums/generation-iii-internal-engine/813229-afr-225-big-bore-72cc-heads-346-a.html

Beaflag VonRathburg

iTrader: (176)

You can get other alloy head studs from ARP that have the same if not greater clamping force / tensile strength, but they are going to be expensive. The problem with the L19s is the hydrogen embittlement. They corrode if not maintaned properly.

camarols1

iTrader: (17)

+1

Give the special order dept. at ARP a call at 805-525-1497
Jay over there set me up with a kit made of their ARP2000 material for $375.
This is a good option for increased clamping without having to deal
with the hydrogen embrittlement issues of the L19 material.

Beaflag VonRathburg

iTrader: (176)

^ They have options all over the place. I was specifically talking about the 625 alloy. That material is the mega bad *** setup they have. The ARP2000 is a really nice material too. Long lasting and close in strength to the L19, but without the hydrogen embittlement.

kp

iTrader: (34)

Welll so they say on the gaskets lol, but I laid them on the heads and they looked fine to me. Maybe I got some small heads or big gaskets

stevieturbo

Im using Trickflow 225cc heads, 5 layer MLS gaskets, and 3.905" bore. So my gaskets are 4.05" bore, stock GM MLS 6.0 gaskets. ( I measured them at 4.05" )
So I have an overlap between chamber/bore

Ive no track passes. But I did recently spend 3-4 hours on a dyno, and some 25-30 pulls. All 4th gear, 9 sec duration 2000rpm-7000rpm where possible.
Most making in excess of 800rwhp.

Logging cooling system pressure. It never exceeded 4psi at any time. Id say thats a pretty good indication of a gasket that seals well !!!!

Regular ARP studs, to 80lbft. New heads, and freshly decked LS6 block.

kp

iTrader: (34)

The 5 layer GMs are working fine for me, only around 8 passes but its nice to have water that smells like water instead of exhaust in the radiator

Whose 5 layer gasket are you using?

stevieturbo

Wish I could say the same about my oil !!!! it stinks of exhaust LOL.

GM 5 layer gasket.

NA$TY-TA

iTrader: (21)

Im with KP...
I see NO Reason to waste the $500 on the L19 head studs for more clamping for when your not going to need it.....
Most dont run into problems lifting the heads until 20 psi plus or around 1000rwhp... even then timing has alot to do with it.....
Stick with the normal ARP head studs and use the money elsewhere......


Kyle

kp

iTrader: (34)

The 5 layer GM's are the 6.2 no? The ones I have are closer to 4.100 bore thats why I ask. The older 6.0 MLS gaskets are 3 layer.

stevieturbo

I'll check later. Im sure they said 6.0/6.2 on them.

I have a spare pair in the garage. But I defo measured them at 4.05" myself.

stevieturbo

Yup. defo marked 6.0/6.2. gasket on right being the 5 layer.