Just got my 94 LT1 back its now a 355 with CC306 cam and a little head work. Just fired it up and sounds awesome but how long before I can take it up to 6500 rpm or so? How long for bearings and rings to sit and seal? Thanks for help

 

You're probably gunna get lots of different answers on this one. If you try a search you'll see this question has been asked before. Personally i drove mine 500 miles before i would bring it up over 3k RPM, still haven't gone WOT (have brought it up to about 5500 rpm is all and let off at 80mph). There was an article i've seen a link posted to several times that suggests running it like you stole it the frist time you fire it up to break it in. Traditionally i thinkt he logic is 1,000 miles before you open it up. Although i think that comes from a period before they had the quality materials that our rings etc. are made of nowadays.

 

You'll get both ends of the spectrum on this. I ran my 383 500+ miles easily and the 496 is still in the 'break-in' period (about 250 miles).

 

Maybe I will be safe not going past 5000rpm for first 500 miles then.

 

Just my OPINION...I wouldn't get it over 3500k for 1500 miles or so if you drive it alot. If it's just your toy, drive it like you stole it, if it's gonna break, better to do it right now.

 

Its my toy I only take it out on nice days. But I still dont want to hammer it and screw anything up. I did not enjoy smashed knuckles and long nights in the garage.

 

if its built good and everything is set right just get a few miles on it and let her rip lol. you never see guys that build all out race cars driving them 500 miles to break them in and lots of em hold up to a lot more abuse then you will put on yours

 

Exactly! When an engine is built and put on a dyno it's usually broken in for 20 minutes or so to break in the cam(if needed) and seat the rings, and then they let it rip after changing the oil and filter. When I built my engine it had about 15 minutes of run time on it before I ran it through the gears. I started it up, checked for leaks, and then accelerated and decelerated in third gear about ten times to break in the rings. Once that was done it was good to go. It has about 11,000 hard miles on it now with absolutely no problems.

When I built the engine for my old Firebird I broke in the cam, drove the car 1/2 a mile and then ran the hell out of it. That was over 3 years ago and it's still running strong. With an LT-1 you're going to have a roller cam, so all you have to do is seat the rings, change the oil if you want, and let her rip!

 

I bought a lt4 shortblock with 28,000 miles on it and after the new cam and all, I still went 500 miles on it and not over 2500rpm to make sure everything was correct as far as breakin it in. IMO, you need to make sure everything is correct if you have all new parts. Why start so early on something so new? Get it right and let her have at it.


Mike

 

When I do an engine I start it up make sure everything is adjusted right. Let it hit operating temperature, make sure everything works (drive it around the block) sut it off check fluids then change the oil and filter (get that moly lube and grease out). Then I refill it start it again shut it off let it cool . (usually over night) then the next day I check fluids start it up drive around listening and watching the behavior, then after its ran at operating temp for a while (fans kick on etc) I take it out for a high way drive, I take it up to speed then let it slow down about 20 mph then accelerate back up to speed. I do this several times making sure no weird noise gauge reading etc occurs. Then I pull over shut it off (walk in get a drink drink it etc) then I go out and run it through the gears.

 

Yeah, you'll want to check everything out once you get it together... leaks etc..

From there it only takes about 4 trips down the strip to seat the rings with a little cooldown time in between each pass.

Long highway on-ramps will work too.

-Mindgame

 

First startup I let it run 25min then went down road 3 miles at 2500rpm or less. Changed oil and filter today and let it run another 15min no leaks all fluids are good. So I'll drive it around town tonight nice and easy and check everything one more time before maybe 5000. Thanks for all help

 

Sounds good, be real attentive. If you have roller rockers its agood idea to make sure they are tight after a good heat cycle initially. Also retighten headers stuff like that.

 

drove around the block changed the oil, let her rip

 

I see it this way. If its going to break then its going to happen right when you start it up. I drove mine down the road a few times and then gave it moderate throttle for a few miles and then I think I had like 50 miles on it before I gave it a little hell. 1800 miles and 6 good races and she hasnt been takin down yet. Dont you just love a good little fighter??