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Discussion Starter · #1 ·
So I got my 9c1 caprice a week or two ago. It has 230k miles unknown if the drivetrain is original or not. I plan on buying a used lt1, found one on craigslist for $400 with wirirng, and doing a complete rebuild on it. My question is I want to get some decent hp out of it while still using it for a daily driver and we have smog here, so any thoughts you guys have on it would be great. I would like to get the best bang for my buck, while keeping it NA. I also plain on, in time, getting a new tranny with around 2400 stall and 3.73 gears. :eek:k3:
 

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A rebuild wont add power, hell IMO most "rebuilds" endup being a step backward when you trust a shop that puts in heavier pistons with thicker ring and lower compression.

See what you have before you decide to tear into it too much.
 

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Discussion Starter · #3 ·
right now I know that the rear main seal is leaking so I figured if im going to pull the motor, why not put a rebuilt one back. I thouhgt about stroking but Im seeing mixed reviews about that. Plus im not sure if the motor has ever been rebuilt, I do know the last guy that owned it didnt know much about it.
 

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power comes from the topend and stroke can help support more heads and cam but if you think displacement alone adds power then I would advise you drop all plans for modifying the engine right now because you will fail. I know that goes against conventional thinking but extra displacement cost a LOT and adds relatively little compared to good heads and cam.

Rear main leaks are often attributed to the LT1 and almost never actually there. More likely the rear of the intake where it is siliconed to the china wall.

Define "rebuild", the stock crank I would put up against the chinese forged stuff, the stock pistons are lighter with better rings than almost any piston set you can buy for under $4-500. Stock rods are fine for most use too.
 

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Discussion Starter · #5 ·
So 220000+ plus miles on a car will have the same hp as the day it was new. There is actually a local guy that is running around 745 rwhp I'm not looking for all of that but I'm sure he kept the bottom end stock!!!
 

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If the engine is in good shape it might not be down on power, only thing that would definitely cost you power now is 220K mile valvesprings are allowing the valves to float, that is only going to be hurting things above say 4500rpm.

Do a compression test, bet it still comes back 180+psi.

Now if it is all carboned up or a stuck injector washed down a cylinder or something that would hurt, but late model engines do not exhibit the bore wear and loss of power older stuff did, part because of the more accurate fueling and part because the rings are thinner and lighter tension so they aren't digging into the cylinders. I would fully expect to find crosshatch in all bores.

If you do want to replace the motor I would do a very simple rebuild on a good condition lower mileage engine, maybe bearings and rings new gaskets. If you want to get more serious you could have the rods reconditioned with ARP hardware but I probably wouldn't bother with that unless looking to turn the motor 6500rpm or more regularly.

People are way too quick to want to put pistons in these and better than stock pistons are not cheap and pistons don't add power.

Here is a guy running the same basic engine setup I have but in a more race setup car.
Ai 200cc CNC H/C Dyno, A4, 425rwhp - LS1TECH
Runs 10.9 NA and 10.3 on a 100shot which has it well over 500rwhp on a stock shortblock. FEW stroker LT1s with aftermarket heads will touch my car much less his.
Here is a car making 700rwhp for probably a quarter what they put in the CM car.
Took The HVYSS Did some Tuning on Race Gas - LS1TECH This guy is just an HVAC commercial refrigeration tech, not a shop with unlimited time and money. This guy used AFR heads in the past and Lloyd Elliot heads in the past before finally doing it right and the car is faster NA now that it was on nitrous with the old setup

That Combination Motorsports car was a no budget spared shop car, not really something that should be compared to most other cars. There are some cars
 

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Discussion Starter · #8 ·
As far as bottom end I really didnt have plans on changeing much, but wanted to have the block cleaned up, micro-polish the current crank if needed and make sure everything is good and solid. Not really sure why you thought I would be using chinese forged stuff.
 

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I wasn't saying I thought you would use chinese forged, I was trying to make a point about the stock stuff being strong.

A lot of LT1 strokers have been built with chinese cast cranks because you can get those cranks for little more than it cost to turn a stock crank .010 under, problem is those cranks are so weak a lot of mediocre setups built like that break the chinese cast cranks, Eagle especially is really bad and really popular.......................

Point being a true rebuild with much in the way of new components costs a LOT more than people think going into it because they don't understand just what junk the cheap stuff on the market is.
 

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Discussion Starter · #10 ·
Ohh ok. I truely believe that the bottom end is solid in these lt1 but if Im going to buy a used one that I dont know the true history on it would be a good idea to pull it apart have the block and the crank check along with new bearings. I know there is know way a $200 crank is worth a crap, wouldnt even consider that. I was more wondering about what are some good top end things I could do, like a good head job cam headers, things like that. But I also need to be able to smog it. And of course the best of plug wires since I would only want to do that once :lol:
 

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Follow Dwayne, the man knows his stuff. If your looking to do an LT1, look up Advanced Induction. It's what he runs on his Caprice. So, if he puts it on his car, it must be pretty dang good.
 

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Discussion Starter · #12 ·
I fully believe He knows his stuff I was wondering what would be the best head and cam combo I should run and still pass smog. Or if I should do other things.
 

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I don't have the link on this computer but at one point I did a big post about all the supporting stuff to have BEFORE going into the engine. There is a lot and it can all make the car much quicker without engine work. someone even had it in his sig for awhile. I will try and remember to fire up the other PC and post the link when I get up. Just got home from work a little while ago and going to bed soon.

Far as heads and cam advancedinduction.com is the ticket.
 
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