Jetmeck

iTrader: (3)

So this head would be perfect for a lot of our cars but its only a 64,65cc chamber.

End up with about same compression ratio. What if I wanted to get about 10-1.

Any suggestions ?

redneckjoe

probably gonna need some flat top pistons? or look for smaller chamber heads.

Jetmeck

iTrader: (3)

Cant find any options out there in an aluminum 190 or 195 head that isnt a 64 cc.

How much would I be leaving on the table power wise if I left the compression 9.6 to 1
instead of my optimum target of 10 to 1 ?

Orr89RocZ

iTrader: (20)

You arent losing much. Most street builds, 1 point of comp is only gonna be 2-3% power at most. A machine shop could likely mill them down to 60cc or so.

Depends how hard you are pushing them. If a big cam and short runner intake like a single plane or miniram type intake, abit more compression may mean abit more than say a mild cam and tpi.

pancherj

Have those heads on my L98. Bought from AFR already milled to 60cc. Also upgraded to the 7/16" rocker studs.

Jetmeck

iTrader: (3)

Did not see that listed as an option. Thanks....

What would a 60cc head due to the stock 64 cc ratio on a stock bottom end of 9.6 to 1 ?

Where is that 60cc head going to put you ?

rgauder

iTrader: (1)

You might be able to make it up with a thinner head gasket.

pancherj

In my 1990 L98, we were right at 10.5:1 (if I remember correctly) using the 60cc chambers and a thin head gasket. The stock pistons were quite a bit below the deck. I just rebuilt the engine with new forged flat top pistons (only 2 valve reliefs), zero deck and a thicker head gasket. It worked out to 11.1:1.

bluegrassz

iTrader: (3)

I used afr 190's on my 92 L98. The 91-92 "or some of" had a different piston than the older L98. It had a factory flattop piston and a stock 9.8-1 compression. We cc'ed the chambers to make sure they where 64cc. I had them milled 30 thousands to bring them to 60cc. I kept the stock pistons / bore / stroke. Then used a GM head gasket. 10105117 which is .028 thick. I ended up with 10.3-1.
Just make sure they flat mill and not angle mill. Go to much and you will have trouble with the intake sealing. I am running a Edelbrock RPM air-gap which both intake and heads have been port matched.
Hope this helped

Jetmeck

iTrader: (3)

So going from a 64cc to a 60cc should get you in the 10-1 to 10-5 compression with a stock L98 shortblock and factory thickness gasket ?

Im going to upgrade to the 7/16 studs for sure.Since Im running an automatic and TPI
whatever cam I end up with Id think the AFR supplied springs and retainers would more than adequate ?

Also could you guys recommend a cam to go with below setup ?

STOCK short block 1989. Headers....3 inch exhaust.....ported base, ported runners and plenum. Stock throttle body Ive read will flow more than enough.....slp cold air intake and underdrive pulleys. 3.27 9 bolt and a approximate 2500 stall in tranny & of course the AFR 190cc heads.

bluegrassz

iTrader: (3)

I am running a comp xe282hr on a 112 lsa. We ended up shimming the stock valve springs to match the pressure the cam required. I am running a carb setup with LT headers. Plus a 3500 converter with 3.73 gears so its a little different. With the mph/et + weight calculator, I am putting around 330hp to the rear tires.

ray jr

iTrader: (2)

im happy with the afr 180 heads you put on mine .. fun little street car ..

cuisinartvette

take factry compression ratings witha grain of salt done be surprised if its really less. youll be fine
Those old 190s are one heavy chunk of aluminum but properly ported area real nice head. Last set I got the exact same # as the 195 (new versino) measured 193cc. At that point why buy new? 2.02 valve is plenty for a 350 too. Those are good stuff
Fwiw their cnc job ran around 250 cfm. Dont know if AFR did it when they were in Pacoima or TPIS did it for them back then

pancherj

I have been pleasantly surprised with how well my ported 190's have performed and held up over the years. On the bench, they went 280/230cfm at .600" lift. After 20,000 miles and hundreds of 1/4 mile passes (all with camshafts having .580" lift or more), I had the heads rebuilt. The valves were cut and a new valve job performed and a couple of guides had worn, but most had not. My old Twisted Wedge heads killed the seats and guides after 5,000 miles and a few dozen passes! LOL