Donor LS1 Advice / Inspection & refresh
Donor LS1 Advice / Inspection & refresh I've searched so pardon me if the question has been asked multiple times. I just purchased my next project car which is a 71 Firebird. I've wanted to put an LS1 in one of these second gens for awhile now. My goal is a daily drivable car with not much more power than the stock LS1. I would be more than happy if I could boost the crank hp to 350-400 range without spending a ton. If it ended up less, no biggie. This will be a street / cruiser car.
Here is my dilemma and where I need advice as I have no experience with LS1s. I plan on purchasing a complete LS1/T56 still bolted with accessories from the donor. Most of these have 90-120k miles. What would you recommend I do to this engine pre-swap to give it a refresh? I may as well do anything necessary while its out of the car. I don't want to tear it down to the short block, but if changing out things like WP, timing chain, head components, gaskets etc will give it life I would like to do it now. Recommendations?
Now for the second part regarding adding power... Should I leave the longblock stock and just not mess with it? Since I am seeking a slightly more than stock hp engine I could prob meet my goals with an LS6 intake, TB, high flowing filter, exhaust and tune. I was thinking of putting in a mild cam to reach my power goals which would include new valve springs and push rods in the kit. I've never done this before though and after reading a few books it does look complicated once you start degreeing the cam. Advice?
Thanks
Here is my dilemma and where I need advice as I have no experience with LS1s. I plan on purchasing a complete LS1/T56 still bolted with accessories from the donor. Most of these have 90-120k miles. What would you recommend I do to this engine pre-swap to give it a refresh? I may as well do anything necessary while its out of the car. I don't want to tear it down to the short block, but if changing out things like WP, timing chain, head components, gaskets etc will give it life I would like to do it now. Recommendations?
Now for the second part regarding adding power... Should I leave the longblock stock and just not mess with it? Since I am seeking a slightly more than stock hp engine I could prob meet my goals with an LS6 intake, TB, high flowing filter, exhaust and tune. I was thinking of putting in a mild cam to reach my power goals which would include new valve springs and push rods in the kit. I've never done this before though and after reading a few books it does look complicated once you start degreeing the cam. Advice?
Thanks
The engine should go 200-300k if not abused. If you have the budget for it. I would do what you have already noted. I would swap out anything internal. External parts can be replaced if they fail. But if internal.. PITA...
I would suggest for your mild build of a DD Curiser:
Oil Pump
Timing set
Cam (can find used LS6 ones pertty cheap, 220-224R).
Lifters (LS2/LS7)
Valve springs (CC 918 or LS6)
push rods
Heads refresh
Gaskets and seals
Water Pump (optional), if it is still working ok. .it is not that much of a problem to change when it fails.
Rocker Arn Trunion Update. (optional)
With these and a mild cam, you should be able to get close to 375-400wrhp. depending on Cam choice and what Intake.
You should be ok with the stock long block. some of the earlier engine 97-98, have been suggested to replace the rod bolts.
just some suggestions..
BC
I would suggest for your mild build of a DD Curiser:
Oil Pump
Timing set
Cam (can find used LS6 ones pertty cheap, 220-224R).
Lifters (LS2/LS7)
Valve springs (CC 918 or LS6)
push rods
Heads refresh
Gaskets and seals
Water Pump (optional), if it is still working ok. .it is not that much of a problem to change when it fails.
Rocker Arn Trunion Update. (optional)
With these and a mild cam, you should be able to get close to 375-400wrhp. depending on Cam choice and what Intake.
You should be ok with the stock long block. some of the earlier engine 97-98, have been suggested to replace the rod bolts.
just some suggestions..
BC
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Pretty much any year stock LS1 pullout from an fbody will do what you want. I'd do a new LS6 oil pump, LS2 timing chain while you are in there for the oil pump, comp cams rocker arm trunion conversion, and pretty much that's it if all you want is 350 crank hp. From there 1 3/4" or 1 7/8" long tube conversion headers, dual exhaust, and a PCM tune and CAI will net you over 350 hp at the crank. Frankly that would probably even get you near 350 rwhp if you do go T56, and even the most conservative 224 type cam would just put you higher than 350 rwhp. Also the newer fbody engines came with LS6 intakes from the factory, you just need to figure out which years, but even with the "worse" LS1 intake 350 rwhp is easily doable on a stock long block.
I'd also check or replace the clutch, slave cylinder, etc, just to make sure you don't take it all back apart a second time. If you do the cam also do valve springs.
I'm basically doing the same thing you are asking about, and I am recommending, but I'm putting the fbody LS1/T56 into a Fox Mustang to replace my old daily driver 2.3L. I was figuring with the mods above (1 7/8 Mustang CHP/Accufab headers that were modified, small cam less than 230 duration, tune, decent exhaust) I want to be somewhere in the 380-400 rwhp range.
Fbody LS1s were rated 320 hp at the crank but often ranged 300-310 rwhp from the factory in 100% stock form.
I'd also check or replace the clutch, slave cylinder, etc, just to make sure you don't take it all back apart a second time. If you do the cam also do valve springs.
I'm basically doing the same thing you are asking about, and I am recommending, but I'm putting the fbody LS1/T56 into a Fox Mustang to replace my old daily driver 2.3L. I was figuring with the mods above (1 7/8 Mustang CHP/Accufab headers that were modified, small cam less than 230 duration, tune, decent exhaust) I want to be somewhere in the 380-400 rwhp range.
Fbody LS1s were rated 320 hp at the crank but often ranged 300-310 rwhp from the factory in 100% stock form.
On my chevelle, with a shock 99 LS1, Headers and a LS6 intake, It was tuned and dyno'ed at 330rwhp.. (should be around 389 flywheel).
So.. stock plus a few bolton and cam change should be a nice upgrade for your DD...
BC
So.. stock plus a few bolton and cam change should be a nice upgrade for your DD...
BC
Wow, thats without a cam swap and on a 99? That sounds perfect to me. I may just go that route. Did you do anything else to you donor motor other than give it a good cleaning and swap the oil pan? I like that gas tank you used. What is it from?
Just cleaned the exterior, SeaFoamed the engine once it was running. But what was key is the Tuner.. I used Mark Romans, he is based here in Northern Calif. Other than that. it was stock.. last month I swapped a LS6 Cam and Springs in, Still running good without a return, but might look into it later this summer, would like to see +350rwhp.
The gas tank is from a 95 Impala.
Good luck with your swap.. keep us posted.
BC
The gas tank is from a 95 Impala.
Good luck with your swap.. keep us posted.
BC
Last edited by bczee; Apr 6, 2013 at 10:54 AM.
