Has anyone built one of the new version ZL-1 aluminum BB Chevy engines and, if so, what did you use for head studs and camshaft?
Thanks

 

Joe Lucia built one…he posts on the NCRS discussion board.

 

Thanks for the reply. Yes, Joe and I have been discussing this for some time now. I am finally ready to begin assembling mine. However, the head stud kit from GM is now discontinued (I knew I should have bought them 3 years ago when they were $160). ARP makes a kit (much more expensive than GM's), but they are currently out of stock (probably due to GM's introduction of the Anniversary 427). I was wondering if anyone else had made a similar build and how they addressed the head stud issue. I am tentatively planning to use the hyd roller cam from a 502-502 crate engine (.527 - .544 lift and 224 - 234 duration), but just want to make sure I have "enough" cam to make some noise, yet be streetable. Running through Stahl side exit headers into 2.5 inch factory side exhaust mufflers. That was why I would like to hear an audio of the 502 crate engine running.

 

Sounds like a good project…I would love to replace my hefty iron 427 with an all aluminum version .

 

Call 'Dart' engineering just outside of Detroit. They have head bolts. George Delorian could probably help you. Also a source for push rods. At least he helped me with everything necessary. ...

 

Rex is this for your #2 car? If so you are running factory mufflers? Also, If you are building a zL1 why not go with a slightly bigger camshaft (not huge) to get a bit more of the motor's potential. there are so many good grinds out there that could be tailored to your needs.Maybe you could contact the Comp Cams tech dept and ask them what they think. GM cams tend to be pretty mild on their crate motors.

 

Stan,

The block for #2 required some minor repairs to the welded in freeze plugs. Comp Cams has already suggested a grind for the cam. Remember......................that one is the 495 cu in Can Am engine, so obviously the GM cam is waaaaaaaayyyyyyy to subtle for it. Don't worry, the 2 car will be plenty noticeable when I'm finished.

Rex

 

Rex, I trust your judgement on that car 150%. I know that when you are done it will be better than ever.

 

What are you guys running for compression ratios? I've rounded up all the parts except pistons, so far. I had originally planned to just do a lighter version of my current (street and track) AH 427, but given the lower thermal efficiency of an all aluminum engine, I thought I'd bump up the CR a touch. Opinions on a streetable ZL1 compression ratio?

 

In my 427 alum engine, I will run 9.5 : 1 compression, same as the General runs in his new Anniversary 427's.

My 495 Can Am alum ZL-1 street engine will be 9.8 : 1 (but I do have an NOS set of 12.5 : 1 Can Am pistons should I "get the itch").

Rex

 

Well there is no sense building a 427 without compression. Personally I would go all the way as a real ZL1 at 12.5 and ruin gas availability, But a set of L72 pistons will still give pump gas road ability of 93-94 octane. It`s a clone anyway just build an aluminum L72. It would probably build more honest HP than the anniversary model and at half the price...

 

For the last several months, Hot Rod magazine has a monthly series describing modifications of a 540 BB. They started out at with 480 Hp/576 ft-lbs and ended up with 793 Hp/659 ft-lbs. Counting the start and stop configuration, they tested about 22 configurations of this engine! I know you're discussing a smaller build up engine, but a lot of their data should be helpful.

I'd suggest building a 454 or 502 cubic inch engine. With internal balancing no one will know the difference. Depending upon cam, etc, you will be getting a different sound however. Easy way to pick Hp.

FYI:
The first engine configuration (480 Hp) was with rect. port iron heads, a Lunati Voodoo hydraulic flat tappet cam (233/241@0.50, 0.554 inch lift), and a Holley 750. For the second configuration they replaced the above cam and went to a Lunati hydraulic roller (231/241 @0.050, 0.600 inch lift exhaust and intake) and a Holley 950. Hp increased from 480 to 515 Hp with this change. ...Finally, for the max configuration, they were using a Brodix BB-2 aluminum rectangular port, Comp Cams solid roller 281/296 @ 0.050 and 0.722 inch lift on exhaust and intake. The maximum compression ratio on the last configuration was about 10.8:1.

To me, one interesting data point is that when they went from a hydraulic roller to solid roller, spring pressures greatly increased. (Of course engine red line rpm greatly increased also.) The big change in spring pressure makes you think that for engine durability for street use, maybe you should stick with hydraulic rollers.