running in new engine

[jono]

What is the best advice for running in a newly built engine (new pistons, bores, bearings, cams etc).

I've done the critical first start up procedure to bed the cams and buckets in but what do I need to do to ensure I bed in the rings nicely?

Jon

[rgh0]

I have posted my procedure before but this is what I do to bed in the rings.

# Use a specialised running in oil or at least just a standard low cost mineral oil. To good an oil can prevent the rings bedding

# Find a quiet stretch of road where you can accelerate with full throttle in third gear from around 3000 rpm to around 5000 rpm

# Do a series of repeated full throttle accelerations and cruise down and reaccelerate again in third gear. Do this for about 60 to 80 kilometres or about an hour.The high cylinder pressures from full throttle acceleration rapidly bed in the rings

# Drive normally for about 500 km and then replace filter and oil with a good quality synthetic and your done .

cheers
Rohan

[jono]

Many thanks Rohan,

I recognise having seen your procedure before but could not find it by searching!

I have a cheap mineral oil in already. Apologies if you've already posted this as well but should I change to a modern synthetic after this or a 'classic' oil - if so what do you suggest?

Do the full throttle cycles have to be completed in one sitting so to speak or can they be spread over a number of outings?

Cheers

Jon

[jono]

Rohan,

Sorry - you've already answered the old query!

When should I check and re torque the head bolts?

Jon

[rgh0]

Many thanks Rohan,

I recognise having seen your procedure before but could not find it by searching!

I have a cheap mineral oil in already. Apologies if you've already posted this as well but should I change to a modern synthetic after this or a 'classic' oil - if so what do you suggest?

Do the full throttle cycles have to be completed in one sitting so to speak or can they be spread over a number of outings?

Cheers

Jon

I would always use a good quality 20W / 50 synthetic. I use Redline for my race car and Valvoline for my road cars . Ok to do the acceleration runs in more than one go but don't drive it any significant distance in between the runs.

cheers
Rohan

[rgh0]

Rohan,

Sorry - you've already answered the old query!

When should I check and re torque the head bolts?

Jon

if you have warmed up the engine and run it for a short time already while checking for leaks and noise then I would also check the head bolts now. I would then do it again after the first 500 km. They should be OK after that. If you get any significant movement at the 500 km check I would check again in another 500km.

cheers
Rohan.

[Chancer]

I have seen piston rings bedded in on a dyno run by sprinkling Domestos into the intake trumpets.

A bit extreme but it was amazing to see what had been very severe blowby all but eliminated and a significant rise in horsepower.

It was a race engine, I would be wary of doing this on a road engine and expecting it to last 100's of thousand miles.

[Spyder fan]

I have seen piston rings bedded in on a dyno run by sprinkling Domestos into the intake trumpets.

A bit extreme but it was amazing to see what had been very severe blowby all but eliminated and a significant rise in horsepower.

It was a race engine, I would be wary of doing this on a road engine and expecting it to last 100's of thousand miles.

Don't you mean Vim or Ajax scouring powder? Domestos is liquid bleach and would just make the bores nice and hygienic

I have heard of that method, but always thought it was a myth or misinformation designed by one or other of the race teams to see if the competition would take the bait, thereby wrecking their engines, but as you have actually seen it done with the correct results I will file it away for something to do when I'm feeling brave at the engine builders

[stugilmour]

Jon, one issue I had was the darned tach was not reading correctly, so another thing to check out first. Can do a rough check with a clip on tach that is on the timing light devise, although I had issues with my cheap one. I eventually used David's excellent spreadsheet to build a table that reconciled engine RPM to GPS measured speed. His sheet accommodates input of tire size, diff ratio, third gear ratio, etc. All OK if the tach is within say 300 to 500 RPM, but something to consider perhaps?

Used Rohan's suggestion and seemed to work well. About 20,000 miles now and compression was within 5 psi across all four. Interesting that I didn't really 'feel' the bedding in with improved engine performance, probably because the carb tune wasn't the best. I recall years ago when I broke in my rebuilt Alfa TC I could actually feel the engine get better (more responsive and flexible) after about 300 to 500 miles on a run from Edmonton Alberta to Vancouver BC. This route used to have large sections where you have the road essentially to yourself to vary the engine speed.

For a laugh I got one of these for the back window.

http://www.ebay.co.uk/itm/Castrol-Runni ... 20bedda176

Cheers and a very satisfying time as you get her running! Pics, pics, pics...

[Chancer]

Yes you are right, definitely Vim or Ajax!!!!

To make you laugh here is one not to try at home, a friend finally served his revenge cold to the financial director of his company that had tucked him up many years beforehand, he (the director) was leaving for another job and had been given his company car as part of the leaving package, my pal decided to give it the once over before it left the workshops and in doing so a pot of valve grinding compound accidentally found its way into the oil filler

The vehicle seized after about 15 miles

[oldchieft]

In the dim past I have a recollection that the engines with adjustable compression ratios used for testing octane numbers, part of the test procedure is to put some form of abrasive into the intake to help standardise the results.

Could be some petrochemical engineer on the forum can give better information about this.

Jon the Chief

[robertverhey]

Might be safer to use something like this before reaching for the bathroom cleaning products....
http://www.penriteoil.com.au/products.p ... oducts=340

[rgh0]

Might be safer to use something like this before reaching for the bathroom cleaning products....
http://www.penriteoil.com.au/products.p ... oducts=340

Yes that's what I use! I think I will leave the domestos under the kitchen sink

cheers
Rohan

[MyLotus]

My comment relates to the type of oil to use after running in. There has been ample proof that 'modern' oils are harmful to older engines due to the lack of zinc. This topic is covered on my website, under : Zinc in oil and its effects older engines, at http://auto-historia.ca/techno/

I am running Yacco L?gendes 15W50 oil with ZDDP. My rebuilt engine only has 1500 miles. Time will tell how long it lasts. Cheers

Alain

[rgh0]

I keep looking for the "ample evidence" and all I find in anecdotal statements of failures from people with no details of engines mods done ( most have lots of mods with heavy valve springs and radical cams) or metallurgy used ( many don't know what the components are they are using) and with doubtful running in procedures.

Many of the reported problems appear to relate to push rod competition engines ( American V8's and A and B series MG engines) with small inverted followers that are very heavily load and relatively poorly lubricated.

I can find no evidence of problems in properly built (with right spring loads and right cam and bucket metallurgy) and properly run in twin cams with using current lower ZDDP modern synthetic oils. if your worried use the High ZDDP versions that many of the makers produce, but I just see no evidence for its need in a twin cam.

cheers
Rohan