I was looking on the web trying to get started on my rebuild on my Camaro. (I guess i joined the rebuild club). I was looking at the 383 shortblock in the SDPC catalog on the internet and called the sales rep. and mentioned that i needed the shortblock with 9/5/1 or either 9/1 compression ratio. He concluded that they did not stock a pistion with that big of a dish to drop the compression ratio that much. The package includes 10/4/1 Dished JE/SRP pistions. He said i need a set of heads to drop the compression ratio to my number. I heard that heads do not drop the compression ratio that much. I goal is to add heads and port my intake and put a blower cam with a 224/236 with .502/.520 lift. Do any body have any comments on how can get to my goal with #12 of boost with a P-1SC Procharger.

Any comments will be blessed!
NiteRyda

 

JE is offering a large dished piston for use with 5.7 inch rods and a 3.75 inch crank. The compression is supposed to be between 9.2:1 and 9.5:1 with 58cc heads. I'll let you know what mine turns out to be when I get everything put together.

 

Heads can make a huge difference. Drop some AFR 76CC heads on top of those JE -31cc blower pistons and you go from 9.2:1 with stock heads (58cc)... down to 8.0:1 or so.

I wouldn't be buying a shortblock from SDPC based on your convo with them.

Call combination motorports and have them put together a real motor for ya, they will set you up right.

www.cmotorsports.com

 

I don't know about Combination's engine building services, but if it's anything like their customer service, you won't be disappointed. I ordered a whole cam setup last Friday and had them ship it 2 day so I would have it by Wednesday. Well, my cam and rockers arrived from Comp. on time, but (since Combination ships UPS, and I know UPS isn't the most reliable) my valve springs, pushrods, etc... didn't show up. When I called them today, they said everything was still sitting there and they didn't know why it hadn't shipped, so they refunded what I paid for shipping and they are sending it overnight so I'll have it tomorrow.

for Combination Motorsports

 

Use one of the many on-line CR calculators (there's one right here on cz28.com) and play with different combos. You will learn something about engines by doing so. The JE/SRP -31cc dish piston is an awsome piston designed for forced induction and it's what I use and recommend.

I prefer a lower CR than you are planning, at least if you plan to run pump gas, FWIW.

Rich Krause

 

Edit: the P1SC redline is at 62000rpms

I have the P1SC and a 383 with "stock unported heads" and cc305 cam. currently I am spinning my blower to ~54,500 when I shift at ~5900rpms. Currently I see 10 psi of boost. This is with a 7.65 crank pulley and a 3.4 blower pulley. I can upgrade the blower pulley to a 3.1 pulley which will spin my blower upto ~59,700 rpms if I shift at 5900rpm, I assume I would see another 2 mabee 3 more psi if I were to upgrade but My 2 core IC is not upto the task of cooling off the extra intake temps. I may upgrade the IC later or add Alky Injection and change pullies but not anytime soon (lack of funds right now)

What I am trying to say with a 224/236 cam and a good set of ported heads, I feel you will make great power with boost but I think you may not hit 12psi. You may want to get a D1SC if you are determined to get 12psi or greater.

BTW, How much power are you planning on making?

Thanks,
Claude

 

I plan to make 550-600 with the blower.

 

With Heads, that 224/236 cam and 10+psi and a good 3 core IC or Twin IC, I think you would hit 550RWHP with the P1SC, possible more.

Thanks,
Claude

 

Just buy the mans shortblock.