Well, I've got another project for my bracket car but I'm going to rebuild my other motor in the 96 Z28. I really want a bad *** motor I wanting to go low 10s. A few questions for right now is of course displacement. Should I go to a 355 or 383? I do not want a 396. And from what I've been checking out on the board is a lot of you are making serious power with a YS or YSi. What would be an ideal compression for a motor like this? 8.5:1? And of course lastly, would I benefit from building this motor with a s/c and switching to OBD1? Thanks everyone for your help!

Checking out some other products, seems like the D-1 or D-1SC are nice as well.

 

Displacement isn't critical, but bigger is generally better. The way to added displacement for an LT1 is increasing stroke. To preserve cylinder thickness, you certainly don't want to bore more than 30 over, and I prefer to go 10 over, as in my current motor. The main disadvantge to stroking is that it limits rpm. However, with a blower you don't need to trun it too fast to get big hp, so that is less of a consideration than NA. Overall, a 3.75" stroke ("383") is the most proven combo, though there are some awesome 396's out there. The longer stroke of the 396 can cause some clearance issues though.

The basic idea is that you should strong over lightweight for the internal engine components. Or, you can get both by spending big $$$ if you are able. But the lightweight rotating/reciprocating parts used to make NA power may not be beefy enough for FI. The pistons in particular need to be deigned for blower use. I did write a little primer on building a nitrous/SC motor that you may find useful. If you'd like to read it, go to www.kennedysdynotune.com and go to "Tech Tips".

Rich

 

Wow!! This is some really awsome information! I'm still reading....

 

Tell me if this is a winner, 3.75 forged stel eagle crank, 5.7 inch h beam rods (eagle i think), and 4.030 16cc JE dished pistons (9.0 i believe as well). Thats pretty stout in my opinion, probably what everyone does. ANything stronger I can go with??

Anyone have expierences with oliver rods and blowers? Mostly in the 18 psi range, with nitrous (cooler intake charge)???

Thanks!

 

Oliver is a great company that makes excellent products. I'd chose their rods over Eagle any day. Otherwise, sounds like a good choice of components to me.

Rich

 

Thanks Rich, I'm also a little concerned belt slippage as well. So I'll have to do a little research on that as well. Probably an 8 cog setup would be fine for me. I also want to check out that ATI BBC Hub as well. I just want to get everything straight before doing anything crazy...it sucks building a motor and finding out that things are going as planned.

What kind of head unit would you recommend for a mid (or possibly high) 9 second 1/4. Like in my first post, I was looking at YS or YSi, but then after looking at D1's and D1SC's....I think those head units will get me there?????

Also the cam shaft, I dont like mild cams either. And I dont think comp cams has anything for me. I've been looking in their book for about 2 hours now. Maybe I can get Brett to do something for me. But also what would you recommend as far as cam shaft design goes? Like I siad, mild isnt fun. CC306 is mild for me. Um, car is NOT daily driven. No ac, no ps...etc...low alt bracket by sjm. But yeah, what would be considered higher than "mild" blower camshaft? I cant find anything interesting.

Thank you for all of your help Rich, that web site is also very informative. And actually, I could get them to do the cam for me. Like I said, I want all my ducks in a row first!

 

I have become a BIG fan of the YSi, 78% effciency is NO joke. Does ATI post their effciency numbers yet?

 

To chose the proper blower size, the following is needed:

1. displacement (which we know will be a 383 or 396)
2. peak rpm (guessing a bit less than 7,000rpm)
3. desired boost??

Rich

 

if your lookin to build a 9 second car, be prepared to spend some $$$. also, i am definately one to go overkill on a bottom end. my buildup right now is a callies race master 3.48", JE blower pistons (havent decided on dish, as i dont know the CC of the heads, but am aiming for ~8.5:1) and the rods im still out on...id like to go with the Manley T6 Billet aluminum rods, just due to their RPM and HP ratings. my goal is 800rwhp off the bottle. as for the blower, it will either be replaced for an X-trim, or comparible turbo.

 

yeah id go with alumi rods...but I'm thinking I'd like to drive up north a few times in the next couple of years, so alumi rods are out for me . I forgot what the cc is on my heads...76 or 67, something like that. I picked some 16cc dished pistons (JE) which gave me a 9.0:1 overall. I have bougfht everything yet, but I'm going to get all the motor stuff and then buy the supercharger in a few weeks. If I can afford to buy the supercharger in a few weeks .

 

For the blower I would go with the Ysi. Vortech makes higher quality components than ati IMO.

But, unfortunately Vortech does not make a YSi kit for the LT1. Most people use the S-trim brackets and modify them. I think the crank pulley would have to be custom made for a cogged setup. Also, Vortech's aftercooler was designed for the S-trim and T-trim flows, not the Ysi. Not sure if the aftercooler would work or not. If you use an air-to-air, it has to be fairly large, otherwise you'll lose too much boost thru it (headloss).

I have the Vortech V2 on the car right now. It is perfect for a street car.