Piston Recommendation for LT1
10-20-2009, 02:31 PM
#1
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Piston Recommendation for LT1
Hey guys,
I am a college student attempting to rebuild the LT1 in my 1994 Pontiac Trans AM. I have stripped it all down and have it at the machine shop. I am told the engine needs bored 0.030" over. Now since I need new pistons because of the overbore, I want to go ahead and get "good" ones. However, since I am a college student, my funds are limited. So what are good pistons for the LT1? do regular 350 flattop pistons work with the LT1? (I've heard they are heavier and can ruin the crank).
Second thing, I plan on putting roller rocker 1.6 Ration rockers, headers, and a bigger cam. Any recommendations on Cams and headers? (I want to maintain street ability/gas mileage). any other good performance upgrades while I have the engine out?
Thank you in advance!
I am a college student attempting to rebuild the LT1 in my 1994 Pontiac Trans AM. I have stripped it all down and have it at the machine shop. I am told the engine needs bored 0.030" over. Now since I need new pistons because of the overbore, I want to go ahead and get "good" ones. However, since I am a college student, my funds are limited. So what are good pistons for the LT1? do regular 350 flattop pistons work with the LT1? (I've heard they are heavier and can ruin the crank).
Second thing, I plan on putting roller rocker 1.6 Ration rockers, headers, and a bigger cam. Any recommendations on Cams and headers? (I want to maintain street ability/gas mileage). any other good performance upgrades while I have the engine out?
Thank you in advance!
10-20-2009, 02:45 PM
#2
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Join Date: Feb 2004
Location: Moore OK
Posts: 2,182
Pretty much all bottom end parts from a 1 piece rear main sbc will work in the lt1.
What are your goals for the car? To get it back to running stock? There are several realatively cheap cast options out there. Summit has several - Keith Black is popular too.
Building a mild heads cam car? Go with a cheap forge if money it tight, or $600ish opens up a lot of options.
Big boost or spray... get a good forging.
Cam wise - What tranny? Gears? Again what are your goals with the car in the end. Stock gears and you want it to run tame then something like a cc305 or hotcam. Shameless plug I have a comp 502 that I need to sell. Almost identical to the hotcam.
If you haven't driven a big cam car though ask around and check one out local. I found my gm847 perfectly streetable and have run bigger custom grinds too. Its all preference. Gas mileage was still good too.
What are your goals for the car? To get it back to running stock? There are several realatively cheap cast options out there. Summit has several - Keith Black is popular too.
Building a mild heads cam car? Go with a cheap forge if money it tight, or $600ish opens up a lot of options.
Big boost or spray... get a good forging.
Cam wise - What tranny? Gears? Again what are your goals with the car in the end. Stock gears and you want it to run tame then something like a cc305 or hotcam. Shameless plug I have a comp 502 that I need to sell. Almost identical to the hotcam.
If you haven't driven a big cam car though ask around and check one out local. I found my gm847 perfectly streetable and have run bigger custom grinds too. Its all preference. Gas mileage was still good too.
10-20-2009, 02:55 PM
#3
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jsetzer:
Thank you for the thoughts, I'm not looking to take it to a strip but I am looking to get good HP gains. I have the 4L60E auto and stock gearing. I don't plan on putting nitrous now, but am toying with the idea for later on. So I would rather have the engine ready for it than have to replace parts again at a later time.
As for the cam, I've heard both good and bad about the Hotcam, many say it is the "way to go" and others say "it's a waste of money for what you get". I would like to go with a bigger Cam so long as it runs good and is streetable.
Thank you for the thoughts, I'm not looking to take it to a strip but I am looking to get good HP gains. I have the 4L60E auto and stock gearing. I don't plan on putting nitrous now, but am toying with the idea for later on. So I would rather have the engine ready for it than have to replace parts again at a later time.
As for the cam, I've heard both good and bad about the Hotcam, many say it is the "way to go" and others say "it's a waste of money for what you get". I would like to go with a bigger Cam so long as it runs good and is streetable.
10-20-2009, 03:32 PM
#4
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Location: Moore OK
Posts: 2,182
I'm not an auto guy so maybe you will find some others to chime in. You will need gears with much of a cam and most likely a stall to get the benefits out of it.
I was very happy with the engine kits I have done with srp flat tops and eagle forged rotating parts. Good parts for the money. Yes there are far better parts for far more money. I would go that route and if you want to throw a 200 shot at it in the future it will hold just fine. Stock cran and rods will be safe to around 500 to the wheels or even a bit more. If you stay stock rods put some good bolts in them.
I was very happy with the engine kits I have done with srp flat tops and eagle forged rotating parts. Good parts for the money. Yes there are far better parts for far more money. I would go that route and if you want to throw a 200 shot at it in the future it will hold just fine. Stock cran and rods will be safe to around 500 to the wheels or even a bit more. If you stay stock rods put some good bolts in them.
10-21-2009, 07:44 AM
#5
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Join Date: Jun 2003
Location: Texas
Posts: 57
When my motor was stock, I added the LT4 Hot Cam Kit, 2800 Stall.boltons and the car has 3.42's out back. Ran in the 12.6's all day long. How fast do you want to go? There are pistons from $10 each to $100.00 + each..
10-21-2009, 09:39 AM
#7
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Join Date: Mar 2004
Posts: 2,705
what is your total budget? How much for pistons, cam, headers?
If you dont plan on spraying the car or any power adders you dont need forged pistons, which will save you lots of money.
Are you planning on running all stock bottom end parts aside pistons??
give us more info and you will get better answers.
If you dont plan on spraying the car or any power adders you dont need forged pistons, which will save you lots of money.
Are you planning on running all stock bottom end parts aside pistons??
give us more info and you will get better answers.
10-21-2009, 09:56 AM
#8
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Join Date: Oct 2006
Posts: 132
If money permits I would get some forged pistons, maybe rods if you really think you are going to spray it. Otherwise, I would just do a stock rebuild, put the money towards a custom grind cam from lloyd or ai, maybe do some basic head porting, and you will have a decent running motor. My 93 has the stock longblock with a cc305 cam, full boltons with shorty hooker headers. It also has a 3400 stall converter, which I would recommend since you have an auto. It is a blast to drive, and can beat some of the ls1 cars with boltons around my neighborhood 
10-21-2009, 10:28 AM
#9
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Join Date: Jun 2003
Location: Texas
Posts: 57
I understand about the funds. I would go with the LT4 Hot Cam Kit. It already comes with the 1.6 RR and its made by crane. I would also just do a stock rebuild, install a higher stall converter. Then in the future if you want to spray you could still spray a 100 shot easily on the bottom end..Yes speed pro are ok and no piston is heavy enough to "Ruin" a crank..
10-21-2009, 12:16 PM
#10
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Thanks for the input.
I will probably take your advice and do what you said.
What converter would be best to use in conjunction with the Hot Cam? Also, the reason I am rebuilding my engine is it reached 230,XXX miles, do I need to rebuild the tranny as well? I haven't experienced any trouble with it, (except having to replace the 1-2 & 2-4 shift solenoids) but I don't want to have to drop everything again in a few thousand miles; I would rather do it all at once. Is there a good tranny rebuild-kit to use?
I will probably take your advice and do what you said.
What converter would be best to use in conjunction with the Hot Cam? Also, the reason I am rebuilding my engine is it reached 230,XXX miles, do I need to rebuild the tranny as well? I haven't experienced any trouble with it, (except having to replace the 1-2 & 2-4 shift solenoids) but I don't want to have to drop everything again in a few thousand miles; I would rather do it all at once. Is there a good tranny rebuild-kit to use?
10-21-2009, 12:30 PM
#11
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Join Date: Jun 2003
Location: Texas
Posts: 57
Tranny
WOW, you got that much mileage out of the tranny..You are darn lucky. Usually when they start hitting 125,000 + miles they go out. I hate to say leave well enough alone but with the extra torque/horsepower you will be making over stock, I'm sure the tranny will not last long..
10-21-2009, 01:07 PM
#12
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Join Date: Oct 2001
Location: Engineerland
Posts: 1,517
Since you say the budget is tight. You can get mahle stock replacement lt1 pistons in overbores of 20 30 40 or 60 on ebay. A set with rings is about 170 dollars to your door and will save you a rebalance on the crank. Otherwise if you have the cash use a set of mahle forged pistons or srp. If you want to never mess with it again put a set of scat I beam rods in it with 7/16" cap screws. You will end up paying for balancing on the crank with either of these changes though.
My words of wisdom to you is that it is not the big flashy parts like pistons cams and heads that kill you. Its the 1000 dollars of nickel and dime bull**** that needs replaced due to old age/wear that really drives the cost up and busts a budget quickly.
The hotcam is just fine for what it is, the cc503 or gm846 would be my next choice. You can still drive either of them with a stock stall and gears and a good tune. The hotcam and gm846 will be on a billet core and the comp cam will be on a cast iron one, billet is more durable but its your wallet so whatever helps you sleep at night.
I would hold off doing a stall on the trans until you get it rebuilt. The reason is if you put a stall in and kill the trans now the stall is full of trash from the failure. It would then need to be cut open cleaned out and inspected. If its not cut open and cleaned the stall will still be full of trash and so will your new trans if you put the stall on it. For converter, brand is important if you skimp here you will hate it. I have used, liked, and recommend vig, yank, circle d, and pro torque converters. You could also do a lot worse than performabuilt (they offer them in packages with a new trans) and I have liked the ones I have driven quite a bit (both trans and converter).
For a mostly street car I much prefer a 2800-3200 stall and 3.73 gears. This will fall right in line with you looking over the hotcam. You will need a large trans cooler as well, get the stacked plate kind not the tube and fin. You can run the stall without the gears but its going to feel a lot like driving in the mud, the gears will help to give it back a nice tight feel.
I do not recommend cutting your teeth rebuilding a 4l60e trans. I can and have done several of them and its not for a novice. The hydraulics need some attention as well as which clutches and hard parts to use where and how they are set up. You are looking at about 900 dollars and change to purchase all the parts you will need to do it somewhat properly plus another 5-800 for a good converter.
Sorry for the book but I have been through a bunch of these build ups and this is just a little of what you need to know before you get started.
My words of wisdom to you is that it is not the big flashy parts like pistons cams and heads that kill you. Its the 1000 dollars of nickel and dime bull**** that needs replaced due to old age/wear that really drives the cost up and busts a budget quickly.
The hotcam is just fine for what it is, the cc503 or gm846 would be my next choice. You can still drive either of them with a stock stall and gears and a good tune. The hotcam and gm846 will be on a billet core and the comp cam will be on a cast iron one, billet is more durable but its your wallet so whatever helps you sleep at night.
I would hold off doing a stall on the trans until you get it rebuilt. The reason is if you put a stall in and kill the trans now the stall is full of trash from the failure. It would then need to be cut open cleaned out and inspected. If its not cut open and cleaned the stall will still be full of trash and so will your new trans if you put the stall on it. For converter, brand is important if you skimp here you will hate it. I have used, liked, and recommend vig, yank, circle d, and pro torque converters. You could also do a lot worse than performabuilt (they offer them in packages with a new trans) and I have liked the ones I have driven quite a bit (both trans and converter).
For a mostly street car I much prefer a 2800-3200 stall and 3.73 gears. This will fall right in line with you looking over the hotcam. You will need a large trans cooler as well, get the stacked plate kind not the tube and fin. You can run the stall without the gears but its going to feel a lot like driving in the mud, the gears will help to give it back a nice tight feel.
I do not recommend cutting your teeth rebuilding a 4l60e trans. I can and have done several of them and its not for a novice. The hydraulics need some attention as well as which clutches and hard parts to use where and how they are set up. You are looking at about 900 dollars and change to purchase all the parts you will need to do it somewhat properly plus another 5-800 for a good converter.
Sorry for the book but I have been through a bunch of these build ups and this is just a little of what you need to know before you get started.
10-25-2009, 06:48 PM
#14
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Join Date: May 2008
Posts: 82
Hdominic...if it interests you, I bought a brand new sealed GM shortblock that was built in '97 and pulled all the factory stuff out. Rods & Pistons including bearings are all still put together. $175 shipped for the brand new GM rods and pistons. People run them to 500 hp without problems. Perfect for budget and i am sure they will be fine for you..
I have pics too. Let me know..thanks
I have pics too. Let me know..thanks
