What is the best way to break-in a motor?

[3.0 GT]

I will being installing my engine soon and it is completely rebuilt. New oversiize pistons and rings (cast pistons), pollished crank, new bearings, new seals and gaskets, new hks 2.0mm mhg with block and head milled. And everything else is rebuild including the tranny. I will need to break in the engine when I get it in and I want to do it right. I searched and saw the article about breaking the engine in hard. Very convincing article but I don't want my rebuilt engine to be trashed later due to a bad break in period. So should I break it in easy or hard? For how many miles? Do the bearings need to be broken in iffeeently than rings? What about breaking in the new clutch? Any input apreciated. Thanks

 

[jdub]

http://www.supramania.com/forums/showthread.php?t=48993

Bearings and rings set at the same time...the rings are what's critical.

 

[3.0 GT]

http://www.supramania.com/forums/showthread.php?t=48993

Bearings and rings set at the same time...the rings are what's critical.

thanks a ton! I must not of seen that thread while searching

 

[dumbo]

A good practise is also to pull your spark plugs and EFI fuse and crank until your see oil pressure on the gauge. You don't have to pull your spark plugs but if you do you have almost no load on your rod bearing. Its just good peace of mind instead of that nail biting first 2-3 seconds starring at the oil pressure gauge.

 

[sneakypete]

although its explained in that thread... make sure you get a straight 30W oil with detergent. not the non detergent oil. i went to a few places and made the mistake of getting a non detergent. had to return it

 

[tturnpaw]

Ive followed break-ins on 4 motors by the dumbo method upon initial startup, and the jDub method thereafter. Although, I wasnt too easy on it for the first 1500

 

[IJ.]

For the hard breakin method you want to be 110% certain of ALL the critical clearences like ring end gap piston to bore and bearings or it will nip up and do damage.

 

[Clip]

i've used jdub's oil recommendation with the hard break in on a completely rebuilt engine, doing well near 8k miles later.

http://mototuneusa.com/break_in_secrets.htm

 

[mirage83]

i've used jdub's oil recommendation with the hard break in on a completely rebuilt engine, doing well near 8k miles later.

http://mototuneusa.com/break_in_secrets.htm

That's the method I used as well. Not really hard running but a good 6 or 7 pulls at 4k rpm. Engine (and rebuilt turbo) sounded sweet.

 

[Doward]

Here's how I've done it for about 10 years now (literally since my first car rebuild)

With 30wt dino oil:
1) Prime the oil pump by hand (or drill)

2) Dry crank 2-3 times until I get oil pressure up (no ignition or fuel at this point)

3) Check for oil leaks

4) Fire the engine up

5) Get the idle and a very rough basic (like, it will drive and run on its own) close, while keeping the rpm away from any specific point. Generally takes 15-20 minutes

6) Drain oil and put fresh 30wt + fresh filter in

7) Take it out and put those first 500 miles on, seating the rings.

8) 4k isn't anything special - you just don't want to redline the engine. I'll do a couple hard runs (on a boosted application, I try to stick with under 6psi) and then let the vacuum pull the engine back down to about idle.

I'll do that 5-10 times.

9) 500 miles, drain the oil again, fresh oil + filter. Refill with 10w30 dino.

10) 500 to 1500 miles, I'm running the engine about 75% of maximum. I don't baby it by any means.

11) 1500 to 2000 miles, I switch to synthetic (used to be Mobil 1, not anymore!) then I drive it like I stole it!

 

[Poodles]

Hard break-ins are how the OEM's break in their motors...

Now, other things like diffs are a different story and they have to be heat cycled...

 

[Carfreak70852]

I wish my motor had half of the goodies yous does. Good luck breaking it in and I hope it lasts you!

 

[shaeff]

Hard break-ins are how the OEM's break in their motors...

Now, other things like diffs are a different story and they have to be heat cycled...

Right on. And the OP said he had his transmission fully rebuilt. I'd put regular dino oil in there for the first bit to pick up any debris that could possibly form or get picked up, and change it out within a few hundred miles.

 

[Poodles]

Depends on what was done to the tranny. If it has new gears, DO NOT BEAT ON IT.

Gears have to wear into each other (on both sides, hence the slowing down part), and the pieces have to heat cycle.

Diffs are the same way

 

[WhtMa71]

Depends on what was done to the tranny. If it has new gears, DO NOT BEAT ON IT.

Gears have to wear into each other (on both sides, hence the slowing down part), and the pieces have to heat cycle.

Diffs are the same way

Good to know! I've actually been wondering...If the diff. has been rebuilt I assume it should be broken in using regular dino 75w90?

 

[dumbo]

Also curious, our diffs specific. If reusing the ring and pinion ect, then how do you break in the friction discs/bearing?