: Running in period .....
03-05-2009, 12:26 PM
hi does anyone know the running in period roughly after an engine rebuild or chains and head , or if there are any rev limits etc per 100 km or miles....i done a 100 km now since rebuild seem to still have a fair few new noises in the engine from the head etc i wondered if this is cos everthing has been out and cleaned and valve seals renewed etc or wether i messsed something up , the tappets dont seem to be noisy i had them in an oil bath the entire time they were out of the head but i have a ticky noise when i release the gass pedal seems to be coming from around the exhaust manifold area but its impossible to pinpoint it sounds similar to the way a noisy injector does but it seems to be in time with the engine when releasing the gass pedal , a freind of mine keeps saying give the engine time i agree but i know from experience saabs only ,make noises when there is something not quite right ...manifod gasket is new and seekms fine turbo i just overhauled it also tested in machines and cant be reason..
thanks in advance if anyone has had similar experience or knows something would be appreciated....:)
03-05-2009, 02:09 PM
A friend was convinced he had a noisy tappet, but it was a leak from the exhaust manifold gasket. Easy way to test is to use a length of tube small dia tube and listen for the noise around the area.
(Be careful of moving parts - obviously!)
03-05-2009, 02:25 PM
ok , sounds like a plan thank you i will try that tomorow funny u said becarefull i burnt my head to day on the rocker cover while trying to find the noise got a great big red mark on forehead now...i personally never heard of a manifold leak that could sound ticky or clicky but u now second person to say it so must be possible, idid check all the bolts today and re torked them the gasket was new a few days back and as far as i know the manifold has no cracks in it but the sound comes from that are for sure i could have damaged my downepipe also alittile i think when i have been moving it about while working on the engine...
03-05-2009, 04:05 PM
yes the exhaust can give you a ticking noise the manifold could be warped thus not pulling onto the gausket correctly.just ask a vauxhall driver they are common for warped manifolds and then breaking studs
03-06-2009, 11:24 AM
To get back to your original question as to how long to run in your engine. The answer is - It depends ! Really it depends on how much work and how far you have stripped it down. After a head job I would just excercise caution for the first short shakedown run, check for leaks, misfiring etc. Valve regrind perhaps a little longer to ensure that the followers are allowing the valves to seal properly. It is not unknown for a valve re-lap to result in the valves not closing, 'cause the tollerance is fairly close on the followers. You should really get the valve stems 'tipped' to allow for the additional seating depth.
Chains, guides etc. Again just needs time for you to ensure that you are not a 'tooth out'. The chain adjustment should take up within the first minute.
Big end, main and gudgeon pin ( small end ) bearings, about 2 - 500 miles, keeping an eye on cranking performance and oil level. If the engine seems 'stiff' on cranking then it needs further investigation. New pistons, rings re-bore or bore honing then treat as fro a new engine and take it easy for 500 miles, no more than 3000 rpm. Gradually work up to full revs over the next 500 miles in fairly short bursts. Be gently and try to avoid full throttle work until getting towards the 1000 mile mark. Change the oil and filter and AWAY YOU GO !
Any strange noises, vibrations need quick investigation. I'd go with the exhaust manifold leak on this one though.
Paul @ Kippen.
PS Once did a big end and re-ring on an A40. It drove me so nuts running it in that I managed to drive all the way from Oban to Paisley ( 95 mile ) at 3000 rpm ( 45 MPH ) steering entirely with my knees ! Don't try this at home folks !
03-07-2009, 03:02 AM
thanks i was hoping someone may know eventually the answer to that question also , everything apart from the bottom end has been done valves seals etc also , valve relap could u explain the symtoms of that , the valves have been cleaned and polished up befor putting them in again and the head also but no re-seating work done there was a very light build up of soot / carbon on them but hardly anything befor i started cleaning, they all went back in the same order as they came out...one thing i did wrong i didnt put the tappets back in the same order they were i had them in an oil bath while they were out i presumed it would be ok they went in whereever but i have since learnt also need to go same way back in from a freind maybe hes not correct i dont know, i will have a good look around again today and pop the rocker cover off just see i havnt left any size 17 ratchets in there or something :)
the chain noises were so easy to identify this one sounds quieter than the the injectors buts its there somewhere and i dont like it , there are no vibrations no at all from the engine which is great after doing the chains but befor i put the boost back up on the turbo i need to be sure what this is , i will also take off manifold today and check that out a bit more..
many thanks for very informative reply :)
03-08-2009, 01:28 AM
You should really get the valve stems 'tipped' to allow for the additional seating depth.
PS Once did a big end and re-ring on an A40. It drove me so nuts running it in that I managed to drive all the way from Oban to Paisley ( 95 mile ) at 3000 rpm ( 45 MPH ) steering entirely with my knees ! Don't try this at home folks ![/b]
What is "valve stems tipped" and why would you need to do that? I have just done some engine work and want to break in the engine, but only going 45mph? Can't the 9000 go 65 at less than 3000 rpm? Or were you in 4th gear? In answer to breaking in the engine, it is usually done for new engines or for rebuilt engines, and it is typically the first 500 miles - low rpm and not flooring the gas pedal! In other words, take it easy and give new meaning to "sunday driver".
03-08-2009, 07:23 AM
'Tipping'of the valve stems is slightly shortening them (grinding the tip off a bit) to make up for the valves being ground into their seats. When they are ground in they effectively protrude through the head under the tappet further.
The A40 wa a 50/60's car and the gearing was then significanly different. Top gear would be direct drive to the diff.
The discussion on running in is also happening on another forum i belong to (TR7). With modern engines and bearing materials (and wider tolerances) there is normally little running in required (that was for the old hand made white metal bearings). The main thing is bedding the rings into the bore, assuming both rings have been changed and the bore honed/rebore etc. The general consensus (for road engines, race engines do not have the luxury of running in) is to take to a little easy for the first 500 miles, change the oil to get rid any crud washed out of oilways etc, and then thrash it to get the rings bedded in. After the gentle run it is not unusual for compressions to be uneven as the rings are not fuly bedded in. Of course the TR7 engine is much older technology (note that it was good enough for Saab to use in the 99 though).
03-08-2009, 12:56 PM
well i had a good look around the manifold all seems to be inorder there no signs of a leakage not on my downpipe either, took off rockercover also all looks good no loose screws flying around or tools left in there from job.....the noise has got a little less to be honest as the kms go up but its still bugs me cant pinpoint it exactly even with long screw driver to the ear its like u can hear the spark plug working if that makes sence not the injector but the plug :) ...anyways still earlydays after enigne work so i will leave it alone for another week car seems fine engine really good so i hope its just something that will go on its own ...unlike the timing chain rattle :( which didnt :)
My view would be that normal everyday driving should be fine provided you don't overload(labour) the engine or thrash the **** off it. As stated above change the oil and filter at 500 miles and then gently build up using the revs over the next 500 miles or so. As stated with modern tolerances it is not as necessary as it used to be but the betting you bed things down then the longer they are likely to last.
03-10-2009, 03:01 PM
thanks i have taken the advice i am still a few miles to go to hit 500 but getting there this noise, i have is definatly coming from the downpipe somewhere i think or thats where i can really hear it through a screwdiver, so in the weekend i will take it off........again and have a better look and weld any cracks i find,
thanks again guys advice is much appreciated :)