I used the search feature but couldn't find anything about this...
I'm just concerned with weight savings and was curious if there were any alum engine blocks that could accomodate a tuned port setup. I've heard swapping to alum heads saves nearly 40lbs.

farge

 

the block used by SLP for a few of the 91/92 Firehawks were aluminum, and were fitted with new heads and the SLP T-Ram (basically a high end TPI setup).
I can't remember the name of the block offhand, but I think it starts with an R.

and yes, you save almost 50lbs going to aluminum heads. I am putting a set of them on next week, rained too much this week and I have a race on sunday so I have to wait.

 

rather then scouring a junkyard for one of the rarest GMs ever made... there is atleast one aftermarket engine block maker that makes genI smallblocks out of aluminum. $$$ though. lots of $$$

that would be sweet though....

 

I went with Aluminum corvette L98 heads. They are really cheap in a bone yard. Just go for a set of those. You can have they built and modified to whatever you need. They also have angled plugs which are nice.

 

The aluminum L98 heads can only be found in Corvettes, right ?

 

as far as I know, yes, only the vettes.
Years that work for our cars are late 86 to 91, with 88-91 being the better of the years with 113 casting heads vs 128.

 

What does the 113's have that make them more efficient than the 128's?
They are both 58CC's, aluminum and angle plugged. The 113's are raised.
How are they so much better? I have the 128's thats why I asked.

 

What's the thing I've heard that one can or can't use EGR with the L98 aluminum heads ?


Regarding aluminum block, THE hardcore way to go, is buying that Bill Mitchell block, I think it's a 427 but can be bored/stroked to 454 or something like that ?

 

I know for a fact that you can use EGR because I am using my EGR with aluminum L98 heads.

 

oh ok *l* so one can basically show up with a 350 TBI with aluminum L98 heads and pass smog (with correct tune), passing it off as a LO3 .. hmm kinda

 

There is no heat crossover on the L98 AL heads so unless you plumb a pipe off the exhaust like on a Corvette, the EGR will not be functional.

 

I would guess not, mainly due to the fact that if you can afford to build a aluminum block, youve changed out your stock TPI a looonnnggg time ago.

 

I know there's a problem finding headers for the D port shaped heads, what about the hmmm pre 88's ? Can one use regular headers ?



Block, yes, very true, if one can afford aluminum block might as well go with LSx.

 

I am not sure exactly what the differences are, but the 113's are worth twice the price of the 128's.
I have the 128's going onto my car sometime soon, just gottat find some time.

 

Doesn't really matter if the EGR functions, atleast on my 350 TBI with functional cats. I had the valve on the manifold, but the EBL did not control the solenoid at the time and the valve did not recieve vacuum. It all appeared to be there, but was not functional. Passed easily.

 

It does in California when the smog tech does an EGR functional test.

 

If 113's are so high and mighty why are you settling for 128's...
I couldn't be happier with my 128's. They are Ported and they made quite a difference.

 

I don't think he is bashing the 128's! He is just curious why everyone wants the 113s over the 128s. IMO, the 128s are the lesser known casting. Kind of like the 300 HP crate engine version of the 083s. The 191/810 versions of the 193s, etc.

 

What IS the difference between the 128's and 113's ?

Did all aluminum L98 heads have D ports ? And if some existed that didn't have the D ports, could one use regular style headers for them ??

 

Try to get your hands on an LS6. That is an aluminum block power plant and if you snag all the electronics you're running in no time. It should also pass most smog laws since it is probably a newer motor than you car.

 

ya, I am not bashing the 128's. I got them for weight savings mainly and they were $200.

 

After doing research, it seems the 113's are rumored to flow better. However I found no evidence. 128's have standard ports for your headers. so every run of the mill header will fit them.

 

Ah ok so they're not raised ports like the D ports, ok.

 

I've been running regular headers on my 113s on my 305 and they fit fine. see the sig for performance

 

This is what I found from thirdgen past... I think its correct:

"To clarify there are 2 version of the Vette AL L98 heads. The original was used from mid 86 through 87 and had the same exhaust port as the iron heads. It's casting # is 128. From 88 onward the exhaust port was raised 0.100" and reshaped like a "D" laying on its side (flat floor and curved sides/roof) for better flow. It's casting # is 113. These are the only differences between the versions."

 

So if one ports the 128's they should flow as good or better than the 113's anyway, the only real difference is in straight from the factory flow ?

 

yeah once u start porting i guess all bets are off between the heads, and the 128's should be as good as teh 113's. vette forums are the best palce for those...everyone gets rid of those things when goin aftermarket and they give them away for a good price.

ofcourse they dont flow all that much better than the irons...so i dont see the point in buying them if you are not gonna port them out. even then, aftermarket heads are better.

but aluminum blocks are pretty sweet but expensive like said. weight savings probly like an ls1, which is like 100-150 lbs i heard. combine that with emissions delete, ac delete, and fiberglass hood and you dropped a TON of weight off the front and the car will be very close to 50/50 weight distribution

 

relocate battery to the trunk, dump P/S and bolt in a S10 steering box .. oh yeah

 

Lets not forget aluminum water pump, underdrive aluminum pulleys, small geardrive starter, etc.