Engine break in on a stand

[mvfd70]

Been searching on here and Google for a while and can't really find what i'm looking for. My engine is at the machine shop now and I want to break it in properly when I get it back. Since the truck is not complete I'll have to break it in on a test stand or sitting on the bare frame. I know to drive it 500 miles easily and then change oil and all that stuff but since I can't drive it, how long and what RPM should I run the engine at to break it in "on the bench?" Thanks

[Highsteel]

Hehe, you remind me of .. .. ME!
I get a new toy and I want to play with it right NOW!
Never mind I ain't got all the parts, I have THIS part, and I'm going to play!

Really though, I've always done the 'break-in' in the vehicle. Are you talking about using a dyno? Are you going tthrough the break-in process with out any load?

I usually break-em in like I'm gonna drive them. Well ok, I do try and stay under 5,000 RPM, MOST of the time.

[Jim_PA]

Don't go too easy on it. After the cam break-in, drive a bit aggressively to get the rings seated.

[spinning wheels]

Originally Posted by mvfd70

Been searching on here and Google for a while and can't really find what i'm looking for. My engine is at the machine shop now and I want to break it in properly when I get it back. Since the truck is not complete I'll have to break it in on a test stand or sitting on the bare frame. I know to drive it 500 miles easily and then change oil and all that stuff but since I can't drive it, how long and what RPM should I run the engine at to break it in "on the bench?" Thanks

To be on the safe side, I would break it in while its in the truck's frame.

I have seen engines run on stands. They were demonstrating their mufflers, but the engine stand was massive. Did you ask the machine shop, if they knew anybody that can help break in the engine?

[stllookn]

Are you talking about the cam break-in? I believe my last one was 20 minutes and vary the rpm between 500 and 2000 or was it 2500? The instructions were with the cam as I recall. I built a stand to do this. It is fairly light weight since you do this with no load on the engine. All the parts for this were basically free. I used an old core support, rad and dash from parts trucks. The rolling stand was part of another old piece of equipment. This allows me to break-in a cam and find any leaks or other problems before I take the trouble to put the engine into the truck.

[mongoose]

you have an engine dyno any where close to you? I think it's well worth the price. I was quoted 500.. mind you canadain monies.. so be a bit cheaper down there.. but 00 to break in the motor and a full tune on it, so drop it in and beat the hell out of it..

[pumpkin]

If it is a flat tappet cam, you need to run the engine at 2000-2500 rpm for 20 minutes to break in the cam. Once the cam is broke in, and the truck is on the road you need to put full load on the engine to seat the rings. Full load would be high gear, full throttle,,,,,not high rpm, high load. With new ring technology, for ring seat in,follow the manufacturers recommendation fist. If it is a roller cam, no break in required . The first run break in for an engine is to break in the cam and lifters to each other. After all that just drive it. Everyone seems to think you have to drive a new engine easy. This idea comes from reading the break in procedure for a new CAR or TRUCK, where every thing is new. Its funny that when people get a new transmission, rear end, brakes, or anything else there doesn't seem to be any talk of break in, but on a new car its actually all the other things you are breaking in for the fist few hundred miles. I love the nascar description of breaking in and testing an engine. Break in the cam, change the oil, and check for leaks and such, do final adjustments, fire up the engine, put a brick on the gas pedal, and leave it for 5 hours. If when you come back its still running, you have a good engine.

[chrislehr]

Originally Posted by stllookn

Are you talking about the cam break-in? I believe my last one was 20 minutes and vary the rpm between 500 and 2000 or was it 2500? The instructions were with the cam as I recall. I built a stand to do this. It is fairly light weight since you do this with no load on the engine. All the parts for this were basically free. I used an old core support, rad and dash from parts trucks. The rolling stand was part of another old piece of equipment. This allows me to break-in a cam and find any leaks or other problems before I take the trouble to put the engine into the truck.

I friggin LOVE it. That is awesome, right there. I may need to try this someday

[mvfd70]

Thanks for the info. It is a flat lifter motor. 250 I6. Another question though...would it hurt the motor any if I reassembled it and then left it sit without running it until I get the truck drivable?

I'm still kind of a noob at complete engine rebuilds.

[68gmsee]

As far as assembling now or waiting, that would be a preference thing.

But, I would prefer to assemble the engine to keep the moisture and dirt out. Either way, just make sure everything is coated liberally with breakin lube (cam, crank bearings) and heavy oil on the cylinder walls (I use STP).

I left mine sitting assembled for about 2 months with a tarp over with no problems.

It's better to break an engine in while your driving the truck but you can run it to make sure everything is working and have no leaks prior to installing. I've also done that before.

[spinning wheels]

Originally Posted by mvfd70

Thanks for the info. It is a flat lifter motor. 250 I6. Another question though...would it hurt the motor any if I reassembled it and then left it sit without running it until I get the truck drivable?

I'm still kind of a noob at complete engine rebuilds.

It can sit for a while. I would use a good quality assembly lube. You can get the assembly lube thru Jeg's, Summit, or any good speed shop. You can even pickup some engine bags, they help keep dust out and rust to a minimum.

As for seating the rings, follow the pistons/rings manufacture's guidelines. Every manufacture has their own preferred method of seating their rings based on their test.

Good luck rebuilding your engine, just take your time and ask a lot of questions, if you don't understand something.
What was the hot tip or the best way to setup an engine 3 years ago, may be outdated and a new better way has been found as new and better materials are being used.

[mvfd70]

Thanks for everyones input. This is an awesome site.

[stllookn]

I'm a minimalist (read CHEAP) at heart.

Here's my new engine...$100. Check compression...135-155psi. Spend $125 on gasket set, new cam and lifters and new double roller timing chain from Summit. Clean and spend $15.00 on paint. Break in cam, change oil frequently and baby it until the rods fall out. Going on year 4 with this one.

Before and after pics.

[special-K]

Wait until it`s in the truck and break it in properly.It doesn`t need to ne broken in until you can drive the truck anyway.You`ll still want to beak it in under load and the rest of the truck will need a shakedown.I have a motor waiting for the truck,too,since 9/07.It may run this year.