Garage > Mechanicals

Initial start after rebuild and break-in process?

(1/3) > >>

raueda1:
After lots of blood, sweat and tears I hope the story of #923 is finally coming to an end.  Some of you may recall that I bent a rod after a stupid fuel distributor rebuild mistake.  My punishment was having to completely tear apart the engine to fix it. The engine will be finished soon and I've tried my best to do it by the book.  I'm still pretty damn nervous though and would appreciate any suggestions from The Collective.  Here's a summary of the work:

* Pistons, rings look excellent (engine apparently rebuilt not too long ago, pistons are +1 oversize).  Cylinder bores all good.  Bores rehoned (deglazed)

* The crank was not removed.  Seals weren’t a problem before and were not disturbed.  Hope I don’t regret this.
* New rod bearings.
* All rubber stuff renewed (hoses, tubing, boots, etc.)
* Valve stem clearance measured.  They were within limits though not wonderful.  New stem seals.
* New timing chain.  Most chain rails replaced (though wear was minimal).  Those behind harmonic balancer were inspected and had no visible wear, so I left them.  Cam sprockets replaced (very visibly worn).  The other sprockets were all in excellent shape.  Cams and rockers are all beautiful.
* New gaskets on all the stuff in front (hydraulic pump, water pump, etc etc)
* Everything else cleaned or repainted
* Reassembly is proceeding using assembly lube on cams, rockers, bearings etc.My concern now is not botching the initial start and break-in.  I envision the following process:

* Fill engine with break-in oil.  Double check other fluids.

* Prime engine: Crank engine with no fuel and no plugs until oil pressure goes up (hopefully that’s pretty fast and also primes the suspension system).
* Install plugs, engage fuel and try to start.
* Assuming it does start, scurry around to set idle and timing to something reasonable and hope the suspension rises.  Check for anything leaking and fix.
* Run engine about 20 minutes varying revs from about 2000 – 3000 rpm.  Change oil and replace filter.  Refill with break-in oil.  Recheck fluid levels, including transmission.
* Recheck state of tune, timing, idle, etc.  Keep driving.  Go for a drive (30-50 miles?) alternating moderate acceleration with coasting (throttle closed, high vacuum) to help seat rings.
* Everything still OK?  Keep driving another 500 miles or so.  Drain break-in oil and refill with conventional oil.  Replace filter, of course.Issues and questions:
My understanding is that running too rich or lean is very, very bad.  How to be sure that this is OK?  Or will CIS K-jet just do the job?
Is my oil change scenario OK?  Better alternatives?  Some say to change the oil after the 30-50 mile break-in drive and refill with break-in oil for the next 500 or so.

Any other advice or caveats?  This is all making me quite nervous ???. Thanks again to all who have helped me through this project.

TJ 450:
Sounds good and with the air fuel mixture, you'll only know when you go to start it. Usually the only thing you may need to touch is the idle air screw and the idle mixture screw if the air flow meter has been apart.

Next thing is, I haven't checked the service manual but it should say to loosen and retighten each cylinder head bolt in sequence to spec after running the engine to temp over a matter of minutes.

Also, you should only add coolant after this is done. Just run on distilled water first.

Otherwise it all sounds very sensible to me.

As for being nervous, that's all part of the fun but it does get a little tense when the first start happens. I'm sure it will be A1.

Tim

Randys01:
Dave

Sounds fine...in fact you've gone a bit overboard.!
You are not actually breaking in much  that's new.....main issue is pistons in reworked bores.
you perhaps have an image of all this swarf swimming around in the oil which is overloading the oil filter with pounds of goo in suspension!!

You do what you like that makes you feel right coz you're the one who has so much  skin in this it's jaw dropping
BUT for mine.......just get it started..check for the obvious then take a nice cruise around the block...do not exceed 2500 rpm for the first 100 miles then start giving it a bit of work ie a bit of throttle but do not exceed 3000rpm until you have 500 on the clock. Gradually work her up thereafter.
I would change the oil at the 500 mile point.
Congrats!

raueda1:
Thanks for all this.  Very helpful.....


--- Quote from: TJ 450 on 25 April 2020, 10:37 AM ---Sounds good and with the air fuel mixture, you'll only know when you go to start it. Usually the only thing you may need to touch is the idle air screw and the idle mixture screw if the air flow meter has been apart.
--- End quote ---
I haven't monkeyed around with it much, so ought to be close enough.


--- Quote from: TJ 450 on 25 April 2020, 10:37 AM ---Next thing is, I haven't checked the service manual but it should say to loosen and retighten each cylinder head bolt in sequence to spec after running the engine to temp over a matter of minutes.
--- End quote ---
Yes!!  I know about that, it's quite clear in the manual.  BUT....   seems like something easy to forget in the heat of the moment.  I'm going to make a big poster with all the critical must-not-forget stuff and put it up in the garage.


--- Quote from: TJ 450 on 25 April 2020, 10:37 AM ---Also, you should only add coolant after this is done. Just run on distilled water first.
--- End quote ---
Excellent idea.  Will do that.


--- Quote from: TJ 450 on 25 April 2020, 10:37 AM ---Otherwise it all sounds very sensible to me.
As for being nervous, that's all part of the fun but it does get a little tense when the first start happens. I'm sure it will be A1.
--- End quote ---
Tim
[/quote]I really do appreciate it.  Devil's in the details and I've screwed myself more than once trying to take shortcuts.  Stay tuned....

raueda1:

--- Quote from: Randys01 on 25 April 2020, 05:18 PM ---Dave

Sounds fine...in fact you've gone a bit overboard.!
You are not actually breaking in much  that's new.....main issue is pistons in reworked bores.
you perhaps have an image of all this swarf swimming around in the oil which is overloading the oil filter with pounds of goo in suspension!!

You do what you like that makes you feel right coz you're the one who has so much  skin in this it's jaw dropping
BUT for mine.......just get it started..check for the obvious then take a nice cruise around the block...do not exceed 2500 rpm for the first 100 miles then start giving it a bit of work ie a bit of throttle but do not exceed 3000rpm until you have 500 on the clock. Gradually work her up thereafter.
I would change the oil at the 500 mile point.
Congrats!

--- End quote ---
Well, nothing exceeds like excess.  If it's overboard that's fine with me.  and there's more skin in the game than I indicated - new accumulators, other steering and suspension odds and ends, brakes, upgrades electrical stuff, much more.  It was really a kind of "restoration lite."  So I really REALLY want it to work. 

BTW, I'm expecting substantial performance improvements given proper valve timing (new sprockets) and degummed CIS.  But we shall see. Thanks and stay tuned for exciting updates.....

Navigation

[0] Message Index

[#] Next page

Go to full version