Jeffers_S13
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| posted on 28/1/05 at 11:52 AM |
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How best to run in a fresh built engine ? ?
Did a search on here but couldnt find anything ? can someone show me a thread ?
Engine rebuild very nearly done, will be putting the engine in a sort of mule car, to run it in for the next month or so this weekend.
How best to run in a fresh built engine ? ?
Had a quick look on google but cant find anything definitive. Puma engines website just talks about after install of a new cam.
I was planning to use a cheap mineral oil for 50 miles with bursts of acceleration and deceleration by backing off to create a vacuum to suck up oil
onto the bores, then filter and oil change to more mineral oil, then 500 miles or so of gentle driving with no long periods of constant rpm, so will
take back road to work probably to help avoid this, then oil/filter change again onto semi-sythetic for another 500 miles of reasonable driving, after
that it will be in kit car with semi sythetic ready for a good pasting 
Any comments ? ? ?
Thanks
James
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smart51
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| posted on 28/1/05 at 12:49 PM |
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same as for new engine running in except less is required.
keep revs below 2/3 of maximum and throttle below 2/3 of maximum for a few hundred miles and then gradually build up.
keep varying the engine speed and load, never spending too much time at a particular RPM or MPH to prevent the pistons bedding-in in a set pattern.
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craig1410
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| posted on 28/1/05 at 12:52 PM |
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At the risk of stating the obvious, use plenty of cam lube on the cam and make sure you prime the oil before firing up. Also monitor oil pressure
closely as well as temperature. As you have said, the oil & filter should be changed early on.
Apart from that, as smart51 says, just give it a bit of respect in the early days.
HTH,
Craig.
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Jeffers_S13
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 posted on 28/1/05 at 01:06 PM |
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Yep, plenty of lube on my lobes 
Will be priming with fuel pump fuse removed and plugs out before I cross my fingers and fire it up...cant wait
Thanks for tips
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chunkielad
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| posted on 28/1/05 at 01:12 PM |
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There is actually a lot of controversy in the motorbike world about running in engines. Some say it's best to let it work it's way in
slowly - others say let it rip and settle quickly as then you have the best seal between rings and bore.
Personally I'd drive easy for a few hunders miles (as in drive like your grandad!!) 
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Jeffers_S13
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| posted on 28/1/05 at 01:21 PM |
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Yeah, I read things like this, I think it may be to do with 2 stroke days when driving gently meant less oil on the bores, so the harder you drive it
after recbuild the more oil gets put through which would be better ? ?
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Stu16v
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| posted on 28/1/05 at 05:12 PM |
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Thrash it!
Have a read of this...
I have always thrashed race engines from rebuild. First race...sit at start line with best intentions of 'taking it easy'. Green
light...best intentions instantly forgot about!
The company van/car that gets caned from new is always the one that seems to go the best too...
Dont just build it.....make it!
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macspeedy
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| posted on 28/1/05 at 06:02 PM |
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we used running in oil on the engine dyno it doesn't contain as many lubricants ran at 50 hp for about half an hour simulates 1000 miles appros
( i forget ) helps the piston rings bed in then normal oil but i noticed a huge difference after my first trackday getting it hot for long enough is
crutial for the bedding in process as we found out after glazing the bores trying to setup our electronic ignition system ticking over a new engine is
bad! you can do the 'running in' on a constant 50 mph drive for 30-40 mins we got the oil from millers oils great prices an all sorts of
oils!!
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rusty nuts
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| posted on 28/1/05 at 06:51 PM |
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Once read a magazine article possibly C.C.C maybe 10years ago that advised against using any lubrication on pistons or rings when building engines .
The theory being that as soon as the engine started the revs are taken to about 2500 rpm and kept there until engine was good and hot.This is supposed
to bed in piston rings and bores quickly without any glazing. Tried it on my old M.G powered mini which pulled very well and didn't use a great
deal of oil unlike most mini's. Must admit it was very nerve racking when first started but seemed to work . Also didn't exactly run it
in gently
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ernie
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| posted on 28/1/05 at 07:40 PM |
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running in
I have just had engine built by Vulcan, 1300 formula locost. They advise Valvoline 20-50 oil, keep the revs to 4000 in gears & 4500 top for 100
miles, check compression every 50miles until 150 psi which should be about 150miles then 5000 revs for 200miles. having said that I have to check the
tappet clearance my feeler gauge is in mm & I need to set 14tho & 18tho can anyone convert?
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Mansfield
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| posted on 28/1/05 at 08:06 PM |
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14 thou' is 0.014".
1 mm = 1/25.4" = 40 thou' = 0.040
therefore
14 thou' = 0.014 x 25.4 = 0.36mm
18 thou' = 0.46mm
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Mansfield
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| posted on 28/1/05 at 08:14 PM |
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Ten years ago, a Performance Bikes magazine ran an article around this subject.
Basically, if you start slowly (only up to 1/3 revs), increase the rev ceiling after 50 miles (1/2 revs), vary the load conditions but dont exceed
half revs for 350 miles, start to open up (but not for prolonged periods) up to 500 miles, and gradually work up to flat out up to 1000 miles, gives
you a 'tight' engine. That means long life, low oil consumption, lower hp and slower engine.
Cane it from the off and the engine will be quicker but die quicker.
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Lawnmower
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| posted on 28/1/05 at 10:18 PM |
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quote:
Originally posted by Mansfield
Cane it from the off and the engine will be quicker but die quicker.
I get a new company car in march, I think I know which method I will be using.
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krlthms
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| posted on 29/1/05 at 12:15 AM |
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Are you not supposed to check the torque on the cylinder head bolts periodically while running the engine in?
KT
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craig1410
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| posted on 29/1/05 at 10:26 AM |
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I think you are for some engines, yes. In fact I think maybe the BL A-Series engine was one where this was recommended but I can't be sure. If
you do and it's an OHV engine then make sure you adjust the tappets again unless they are hydraulic of course.
Craig.
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rusty nuts
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| posted on 29/1/05 at 05:35 PM |
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Most modern engines now use stretch bolts that are only torqued to a very low setting to settle things and are then tightened using an angle gauge.
This gives an even clamping pressure for the head and gasket.
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Peteff
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| posted on 29/1/05 at 06:28 PM |
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All the article is interested in is ring seal from what I can see. It doesn't seem to take in any of the other stuff in the engine. He also
mentions they are modern engines. Old pintos and x-flows might not take so kindly to it.
yours, Pete
I went into the RSPCA office the other day. It was so small you could hardly swing a cat in there.
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chunkielad
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| posted on 29/1/05 at 08:49 PM |
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Its only the piston rings and the bore walls that matter really, cams etc don't exactly settle in due to heat. If anything, you don't want
them to change from manufactured spec much if at all.
You are aiming for a good seal between rings and wall and the best way to get an even seal is to heat the whole thing quickly (to get expansion) and
then let it cools slowly so it doesn't get brittle or shrink too much. Hence driving 'hard' for a while would sort this and keeping
it up would help to keep the heat there.
I however am a big girly coward and wouldn't like to take the risk!!!
I really don't think that the age of the engine is relevant as new metal (replacement rings or brand new rings) will act in the same manner.
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The Shootist
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 posted on 30/1/05 at 02:05 AM |
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To throw in one more variant....
My sources suggest avoid the high revs, but to lug the engine with full throttle accelerations, but not revving too high. The lugging causes high
cylinder pressures which force the rings to seat before they can attain an oil glaze.
Synthetic oil should not be used until the oil consumtion stabilizes, and can be over 1,000 to 6,000 miles.
Bearings and cams shouldn't care how they break-in as they have an oil film and shouldn't touch anyway.
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craig1410
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| posted on 30/1/05 at 12:18 PM |
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On the subject of ring seal, all the engine building books I have simply attribute the quality of the ring seal to the quality of the crosshatch
honing on the bores.
Also, I have two highly reputable books which I bought recently which hardly even mention the process of running an engine in. Given the amount of
detail which both books give about the actual process of rebuilding and blueprinting and engine this is either a serious ommision or alternatively
both authors don't see it as a big deal.
However, both authors stress the importance of a Moly Di-sulphide cam lube on lobes and lifters and strongly recommend oiling the bores before initial
firing to ensure good compression. The final piece of advice is to run the engine for at least 20 minutes at 2500RPM and then drain the oil and
replace the filter. The use of an oil additive (eg. GM Engine Oil Supplement) is mentioned and all the other obvious stuff such as priming the oil
system.
HTH,
Craig.
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chunkielad
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| posted on 30/1/05 at 01:06 PM |
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It seems like there is no definitive(sp) answer to this one. I strongly suggest that you take it as you feel safest. As long as the honing etc is
sorted, DEFO lube EVERYTHING as it's the only protection the engine really has. If you wanna take a risk and run it hard, do so. If you feel
it's too big a risk, do the 2.5K thing and then change oil and run it slow after that (max 4k).
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David Jenkins
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| posted on 30/1/05 at 02:46 PM |
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This is the issue I'm rapidly approaching - I've just rebuilt my engine due to cam failure. Originally I thought this was due to an oil
failure I had a while ago, but now I think it's probably due to not running the engine fast enough at first start-up.
The instructions I've seen all say that the engine must be run at 2000 - 2500 rpm for 20 minutes to bed the cam in, otherwise premature cam
failure is VERY likely.
The trouble is, when you've just rebuilt an engine you're not sure whether the ignition timing is set right, or whether you've got
any leaks, and so on. The last thing your instincts say is "run the engine fast"!
I'll have to do this in the coming week, so it's going to be an anxious moment until the 20 minutes is up... as it is, the cam
instructions say not to turn the engine on the starter for too long, but I did want to make sure that the oil pump was primed and running before I ran
it properly - just managed to pass that hurdle. At least everything inside the engine was plastered with Graphogen colloidal graphite goo before I
did this!
rgds,
David
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craig1410
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| posted on 30/1/05 at 05:51 PM |
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David,
Yes I've built a few engines in the past and this is always a scary moment isn't it! The engines I have built are mainly BL A-Series and a
couple of vauxhall OHC engines. The Vauxhall engine is notorious for snapping camshafts as it happens.
There are always those who swear by slightly unusual methodologies and I have no problem with that but I think the conventional wisdom with running in
engines is to avoid full throttle, avoid more than 3/4 max RPM and very importantly avoid labouring the engine at low revs with high loads. Again the
conventional approach to initial startup is to check all your fluids, electrics, and mechanical items before starting the engine and make sure you
have carefully followed the static ignition timing procedure. That should allow you to run the engine for the requisite 20 minutes at 2500RPM without
worrying too much. Of course the inevitable smoke which comes off the exhaust after a rebuild will always keep you on your toes (and your hand on the
fire extinguisher...)
On the other point, I would ALWAYS advocate priming the oil pump although you should be careful not to wash the Moly lube from the camshaft. If
it's an OHC engine then you can always reapply some lube after priming and on some engines you can spin up the oil pump without cranking the
engine (eg Rover V8) using a little priming tool.
I'll really looking forward to rebuilding my Rover V8 over the winter next year!
Cheers,
Craig.
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Jeffers_S13
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| posted on 3/2/05 at 05:30 PM |
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Well, wish Id never opened this can of worms !
I think tonight is the night, only got a few more bits and bobs to do, Im not sure I want to go for a drive in the dark though in case I cant see any
leaks ?! to make it worse I have to drive down a long sh!tty farm track to get to the road so all my cleaning efforts are gonna be covered in cow cr@p
in a matter of minutes 
I havent put new cams in, just the same old ones but its been honed and has new rings, new bearing shells and new valve guides. I think the suggested
20 mins at 2500rpm is more to do with bedding in cams, I read this on the Puma website, so not sure about my engine really.
Still very confused...
James
[Edited on 3/2/05 by Jeffers_S13]
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craig1410
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| posted on 3/2/05 at 07:01 PM |
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If you're not using new cams it is very important that you kept the cam followers and cam lobes paired up. It's a bit late to tell you if
you've not done this but it is very important. If you've not done it then the engine will probably fire up okay but the cam and followers
will wear out very quickly and in some cases you can get more immediate problems.
You're probably right about the 20 mins at 2500 RPM thing being especially important for cams but at the very least I would run it at 2000 RPM
until the thermostat opens (very hot top hose is usually a good indication of this on most engines). Don't leave it at idle speed because oil
pressure is very low at idle and the engine isn't very efficient. You want to get the engine hot to get all the metal bits expanding and then
contracting as the engine cools down again. That's when you will see any leaks. Put a clean bit of cardboard underneath the engine if you have
one (eg. An old cardboard box opened up) as it's easier to see any leaks.
Final bit of advice, don't be scared - just turn the key and enjoy!!
Cheers,
Craig.
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