Engine ?

I’m thinking about having my engine rebuilt at the end of this season with about 450 -475 runs on it. This is a SHP sbc with 13-1 and Compstar rotating assembly with studded mains. The maximum net valve lift is .655 and engine never sees over 7300 rpm.

My car is as fast today as it was back in August 2015 when the engine was built. This is the first engine that I’ve owned that has made this many runs and is still together. The prior 3 engine expired before 230 runs.

This is one of my questions. How many runs should one expect to be able to put on an engine like this prior to rebuilding?

youre on borrowed time

Oh man, hard to top the technical expertise from that last response Mark. I mean the breaking down of how the rods aren't designed for X amount of runs with bearing life details and the stroke of the engine comparisons were top notch. Hard to follow that one.

I've had engines that have lasted 100 runs and some that have lasted 400, hard to tell when you need to rebuild besides leakdown values, bearing wear patterns and et loss's but you know that. I think some bump there rebuild intervals up due to past experiences. Id rather hear it from a manufacturer on what they expect from their parts, also from other builders who have regular knowledge of how long a rod can last or what have you.. I'm no expert but I'm at 310 on a BBC and its coming out this winter...

There's obviously no magic number and so many variables. How clean is the typical race environment and do you use an air filter, how is the fuel tuneup and typical oil condition?

I don't want to know your answer to these, but those things are going to be big contributors to engine life.

I'd definitely be wary of lifters at that point if we are talking about needle bearing rollers. Valve springs may be wearing out, or may just be getting broken in. At least those are easy to check.

Beyond those things, you could yank it out and pull the caps to look at bearings and probably change the rod bolts if everything else looks good.

I've always run things 2 seasons and then freshened. I'm going to go a third season since I spent a good chunk of last season waiting for cylinder heads. I could look in my data for a run count, but I've never done it that way and don't have a benchmark.

All the above questions, and more!

1/2 track or full track? Big difference between 1/8 and 1/4.

Roller lifters? Every 400 passes or so with the cam you listed above seems a safe length of time to use them, again, 1/8 or 1/4?

If you have an honest engine builder he will take it apart and tell you how things look, that will help you determine when it should come back out again.

Once I went to aftermarket blocks I could keep the rings sealed nicely, bores were no longer distorting. My stock GM 400 block couldn't go more than 200 passes before I would start to get blow-by. My Bowtie and Dart blocks just seem to stay round forever! I freshen at 400-500 passes to be safe, but also turn 8000 most passes, and 1/4.

My bearings are always 100% perfect, never ate a lifter. Valve springs are my biggest concern on my engine.

Mike, there’s less than 100 passes at 1/4 mile and the rest at 1/8 mile. My engine spends a lot of time (over 3 seconds in a 6.50 run) at 6250 rpm (convertor stall) completes the shift @ 7000 and finishes the 1/8 mile @ 6500.

Yes this is a roller cam, Isky Durathon lifters and I always have the oil temp over 140* prior to entering the water box.

My longest high rpm is in the water box @ 6800 and driving out which is 5 seconds.

I’m looking at a different engine shop to do the rebuild this time.

mark
that's an amazing amount of runs,especially on lifters.
im the type of guy that would rather be safe than sorry and at least looks things over 175 to 200 passes.
and at 475 passes why would you even think about changing engine builders!!

I agree you are overdue. Also why change builder unless guy who did it is not available. Hed did you good job sounds like.

Now tow things would make me nervous. Number of runs. Having asked question and stated how good its been this far tells me your gut knows its time.

If it ain't broke don't fix it.It will break and tell you exactly how many runs it was good for.

This engine was originally built by a shop that took over 6 months to complete. This is because I was using a new set of heads that were professionally ported along with the intake manifold that I purchased directly from the company I delt with instead of using the builder for this head / manifold.

This engine lasted 15 runs and ran out of oil pressure under load. Instead of taking it back to the original builder for fear it’d sit another 6 months before repaired I took it to a different builder to find the problem.

This builder took it all apart (to include the brand new heads that were not a problem) and rebuilt everything. The 2 things he did fix was the oil pressure and lack of oil pressure during shut down.

The three things he F’d up were the replacement valves and valve springs that didn’t need replacement and he decide that the 102* cam setting that the cam was originally installed at should be 104* instead. When I called the head builder and told him this he said he F me big time and I agree. The oil samples after this rebuild with extremely high titanium numbers confirmed this. The car was actually .20 slower in the 1/4 after I got this engine back and had to change the pill by 10 sizes to get the ET and MPH back to where it was.

This builder didn’t have a clue about mfi and didn’t have a dyno set up to run mfi as well. And THIS is why I looking for a new shop.

I’m also considering replacing the short block with a new short block. I believe the cost in tear down and rebuilding these components are expensive and all you have are used rotating parts when done. I’d keep the Select Melling pump, cam and covers and sell the old short block on Craigslist. I’m also considering using a Eagle rotating assembly instead of Compstar if going this way.

I do not have the ability to build or wrench on engines. I rely on an engine shop to do all of this for me. I also want my engine run on a dyno for break-in and to confirm that all is correct. I do not have a problem paying for quality work. My problem has been finding an honest engine shop that can do this.

I don't know how many dyno cells are set up to completely measure the fuel usage in a MFI setup.

I make a handful of pulls on gas to get a baseline and seat the rings. Then put the Terminator on with a long hose from the pump into a fuel jug, and some long return hoses to the same fuel jug. Then just change the pill and timing to find the best torque and HP.

Also, unless you have a Moroso billet pump or a Titan, I throw my oil pump in the trash and replace with each rebuild.

quote:

This engine lasted 15 runs and ran out of oil pressure under load. Instead of taking it back to the original builder for fear it’d sit another 6 months before repaired I took it to a different builder to find the problem.

lol mark you kinda left all this info out on your first post

I would be completely tearing down and replacing a lot of parts at that number of run with my combo. But I turn a lot more rpm than you do. And rpm makes a big difference in the life of parts. And HP level.

quote:

Originally posted by Lenny5160:
Also, unless you have a Moroso billet pump or a Titan, I throw my oil pump in the trash and replace with each rebuild.

You’re recommending not re-using a Melling Select 10552 pump with under 500 runs on it for a 650 hp sbc?

If the pump body has no scars and oil pressure has been fine with the clearances current, then clean it and use it.
Kinda like bearings, they dont wear, unless there is an issue with clearance, balance, or oiling, but they get replaced. Mainly because the customer would have a cow if they weren't.
Mag the parts, new rod bolts, pins,rings,lifters if needle type,springs, possibly chain,possibly bearings.
Touch hone, check pin bores (use +.001 pins if the bores or rods need honing) valve job, check guides, check b.e. and resize if req.

quote:

Originally posted by markemark:

quote:

Originally posted by Lenny5160:
Also, unless you have a Moroso billet pump or a Titan, I throw my oil pump in the trash and replace with each rebuild.

You’re recommending not re-using a Melling Select 10552 pump with under 500 runs on it for a 650 hp sbc?

I don't have any scientific reasoning, but I always replace.

I wouldn't mind reusing the pump if you take it apart and it looks perfect. But lifters, that is something I never trust to leave in past 400 some runs.

Lot of passes pull it and replace parts. Likely wont make many more passes.. The wick is short..