new motor

[buickbert]

ok i spun a bearing in the stock block, im looking to rebuild it and need some advice. i want the car to go around mid to low 12's and still be more then streetable, i know you guys will tell me this wont be too hard. this is my first venture into turbo building so bear with me. im a 24 yrs old with a little knowledge but dont know it all. i have way more experience with my 72 big block skylark.
what kind of pistons should i use? whats the diff between hyperutectic and forged? what kind of cam, i was thinking about poston gn107 i think it is? fuel injectors? i have a set of rebuilt heads that have a 3 angle valve job and comp cams springs locks and retainers (courtesy of ebay, 315.00 already done). adjustable fpr obviously. im planning on using postons ceramic coated headers because the car has an after market set on now that i dont like (both sides flow down into the crossover and then up to the turbo in another pipe, it doesnt seem very efficent to me). maybe a th downpipe? is there any markings on the stock turbo to let me know that it is stock? im not sure if it is. when i bought the car it came sith a stack of reciepts including 1 for a atr stage 4 kit? art carr built 200-ra with 9' conv? 4.11 in the rear? a kenne bell ultimate chip? any info would be very appreciated.......

thanks alot
robert petrone
87 gn
72 462cid skylark

 

[buickbert]

anything helps guys.....................

 

[ledzeppac]

go to GNTTYPE.org and read.

Low 12's are simple with a internal, turbo, heads, headers, etc, etc etc...

Your in Arizona, so call Arizona GN and ask for Nick. He will tell you what to get.
Do a search for Nick Micale for the number on this board.

Don't get to far ahead of yourself

 

[Red Regal T]

Why do you want to buy pistons. The stockers work great. If you have 4:11 gears, that's a mistake. You need 3:42s.

 

[buickbert]

i dont really WANT to buy new pistons, that is only a thought if it needs new ones. the car had the 4.11's when i bought it. just a question, why are the 4.11's a mistake? does it make the motor rev too fast? so if i have stock internals, the little bit of work done to the heads, upgraded fuel system, headers and exhaust, the chip, art carr 200-r4 with a 9' conv, then the car will in theory go somewhat close to my goal if i got a set of 3.42's?

thx for the reply
robert petrone
87 gn
72 462cid skylark

 

[BEATAV8]

i dont really WANT to buy new pistons, that is only a thought if it needs new ones. the car had the 4.11's when i bought it. just a question, why are the 4.11's a mistake? does it make the motor rev too fast? so if i have stock internals, the little bit of work done to the heads, upgraded fuel system, headers and exhaust, the chip, art carr 200-r4 with a 9' conv, then the car will in theory go somewhat close to my goal if i got a set of 3.42's?

Yep you got it.. the 4.11 gear does not agree well with the turbo V6 rev range / torque curve. With the stock 3.42 gears you will be very happy near the top of 3rd gear at the end of the 1/4 mile.

Everything you have listed there for mods is great. It sounds like you currently have hooker headers.. which most folks will tell you are no good. Stock headers or the postons headers like you want will work great even into the 10's.

 

[Blown&Injected]

Does not take much to get to 12's.

I would leave it all alone and do the best you can with what you already have and only re-do what does not work.

As mentioned read the GN T-Type Org pages - SPRING CLEANING is good to get your "base line"

When all is working properly and set right, MAF, O2, TPS, EGR working properly, no vacuum leaks, no oil in the Intercooler and throttle body, coil/wires/plugs in good condition... then start looking at your limits. These are usually fuel: need good pump and power to the pump; and air: big turbo and good IC. Of course the air must get out via good down pipe and by now most cars have already been thru at least one aftermarket exhaust system.

At 116 MPH in the 1/4, I am thinking about going with some 3.23:1 or 3.08:1 gears. With 4.11's, you will need to shift to OD before the end of the track and the torque is big enough that it is already hard to get off the line without spinning.

As far as camshafts - Full Throttle Speed has some deals on roller cam kits. These cars do not need much cam and do not rev high so no need to do a cam unless going into the engine. I, personally, still have BIG BLOCK on the brain and still buy the bigger cam shafts - does not seem to hurt, but many running VERY good on the stock cam. Flat lifter cams have some issues wiping the #3 exhaust - make sure your springs are not too hard!!!

Pistons: If you need to rebuild go with forged - It is said that the Hypers are to prone to cracking. With lots of boost, some knock will happen and that beats the hypers up. I had hypers that did not crack on the top in the ring lands like one might expect, but there were cracks in the skirts.