I have a chance to buy a polished Vortec system with an after cooler for $500. I am in the middle of a 355 build and was wondering on the piston setup. I need to get down to around 9.5:1 compression. This is a lt-1 in a 94 z28. Will the pistons give me that compression, or will i need to go with some bigger chambered heads?

 

For $500 I say go for it! Also get dished pistons.

 

Pistons will get you there; they should be available in in several dished configurations (i.e. -11cc, -23cc).

 

The guy I am buying it from had it in his camaro that he wrecked. Now he is just parting it all out. He said he paid $3200 for the whole kit and it hasn't really been used that much. I spun a bearing a while back so I already have to rebuild it. Now some rust has set in the cylinders so a .030 overbore is a must. I want to do a budget build so would the stock crank, stock rods, studded mains, and forged dish pistons hold under that kind of boost? Or do I absolutley have to have forged rods? Another question: I have a LT4 hotcam kit and gasket matched stock heads with stock valves. I know this is not the ideal setup for a blower, but will it still make pretty good power for now, until I do another cam/head swap?

 

Stock crank and rods will easily stand up 500 rwhp, maybe a bit more. Have the stock rods shot peened to relieve stresses prior to reusing. The hot cam is not a blower cam so it's not ideal for your combo. Comp cams has several blower cams; I'm running the mild 218/230 114LS cam and I'm making 542 rwhp with a LT1 350 motor, forged pistons, 9.7 CR, mildly ported LT1 heads, 10# of intercooled boost and JBA shorty headers.

 

how much is shotpeening the rods and can a local machine shop do it? Some h-beams are not really that expensive so I might go that route. As far as the mains go, can I just stud them instead of going with splayed or 4 bolt conversion? I am trying to keep it pretty cheap. Like I said I already have the hotcam kit, so I will probably just stick with it until I save up a little more and get a good head/cam. What kind of power should I be looking at with 10 psi of boost with that cam? When you say mildly ported heads, did you go with bigger valves or just some gasket matching? Sorry so many questions.

 

I had my rods shotpeened and the ridges ground off and topped it with arp bolts. Go for a piston with a dish of 20-25cc. SRP and Speedpro/TRW are the most popular. DONT forget that you will need more injector with the blower, probably go 42+ to start that way you have some room to grow. You'll also need the T-rex off the donor car. OBE1 was right that the hot cam isnt the best for a blower, but you can use it for now if money is tight. There are far mor worse cams out there. Ideally a blower cam needs to have a LSA of 114-116.

Buy the blower and get the good deal while you can but do some research to see what you are getting into, I suggest that you go to vortech's site and read the install manual for the Fbody so that when you go to pick up th eblower you know what to take and what he is leaving out. try some searches in this formum if you have some more questions, theres alot of info to be had.

 

thanks man....i have had a hell of a time getting info on this. I have done numerous searches with no luck. BTW how much boost are you running?

 

If you're going into the motor i'd spend an extra couple hundred over shot peening to get a set of forged rods. Definetly worth the money, and will definetly increase your power handling capacity.

 

the stock crank should be fine then right? Also, will just studding the mains be good enough? I really don't want to spend $700-$800 for splayed or 4bolt conversion.

 

hey obe1. youve got the stock head with the 58cc CC right? what CR are you at, with which -cc pistons?

1-bad-z28....im going to be going the same route you are with my build. ive been looking at some of the rebuild kits in summit. my motor doesnt see much abuse at all so im not going to build a motor that can withstand 1000hp and 20+psi or anything. just want a motor that im not worried is gonna seize up everytime i put my foot in it ya know....

 

Probe makes a pretty good set of low compression pistons for LT1s. They're a 20 cc dish forged piece and yield around 8.8:1 compression with our heads and an appropriate gasket. They're right around $325 bucks. PN: P2441F-030

 

Those things are perfect. They are $359.95 from cnc motorsports and they come with rings. My question is are the pistons and rings anygood? The rings are Total Seal Classic Race Rings. Here is the site: http://www.cnc-motorsports.com/produ...408&CtgID=7124

 

Thats the same part number that speedpro/TRW uses, wonder if it the same piston. Cheap but heavy.

 

how heavy and how much would it effect power?