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MG MGA - Breaking in rebuilt engin

I've searched the archives and can't find much on breaking in a rebuilt engin. One posting suggests usind non detergent oil. Another suggests varying the speeds. I'd be interested in any suggestions as to methods that any of you feel are beneficial to the break in process.
J. Hudrlik

If there is a new cam, it should be run at 2000-2500 rpm for the first 20 mins, to ensure a good oil supply to the cam lobes. Also use a mineral oil with ZDDP, such as Shell Rotella diesel. No synthetic. Change oil after a very short time, then again at 500.

Art Pearse

Hi, the cam and lifters should be coated with a moly based assembly lubricant to facilitate break in of these parts. Molyslip additive can be added to the motor oil if necessary, instead. The engine should be run at around 2000 rpm for the first half hour or so. When you drive the car, vary the road and engine speed. Back off on the throttle often, to help suck oil up into the piston rings. Do not run the engine up to redline for the first 500 miles, but do increase the revs gradually as you approach 500 miles of driving. Drive the car for 500 miles, then change the oil and filter. oil consumption may be somewhat heavy until the engine is fully broken in, so watch the oil level carefully. Hope this helps! Glenn
Glenn Hedrich

I am not a specialist , which is why I had Dave Hedley from Fab Tek rebuild the engine for my MGA here are his instructions for Breaking in the newly rebuilt engine. (this is long but informative.)
{I will skip the page of installing the distributor}
Install all fluids and verify there are no leaks! and Battery is fully charged! Prime the oil system:
Remove the plugs before cranking/priming. If the car has an oil cooler place the oil in the line going from the rear fitting on the block to the cooler in a 1 qt or larger can so it will catch the oil.
- Spin the engine (ignition off) on the starter until oil flows into the can.
re hook hose to the oil cooler. If you do not have a cooler oil is pumped directly to the filter) preform this step with a short length of heater hose slipped over the block fitting then install pipe or hose to the filter fitting.
With oil lines tight crank the engine just long enough to register oil pressure, you should see 30 psi plus.
Note prolonged low speed cranking is very hard on the new cam.
Reinstall plugs and wires
you are now ready to start.
Ignition starting-
Raise idel speed by turning idle screws a full turn open you may need more after starting.
As soon as the engine starts raise RPM to at least 2,000rpm run engine for about 1 minute, then shut off for 30 minuets use this time to look for leaks check manifold bolts are tight etc.
Cam break-in This is very Important!
The engine needs 30 min of cam break in at 2,000 + rpm (low speeds are hard on new cams) this should be done in spurts depending on water temp keep tempo at 200 degrees or below.
Engine brake in Driving:
Bearings do not need break in
Rings Do!
First 10 miles No WOT (Wide Open Throttling ) and no steady speed driving .
After 10 min drive normally with periodic short bursts of heavy throttle to seat rings.
By 100 miles the rings should be seated and it is OK to run steady cruising speeds
Any time you "Cold Start" let the run 30 - 60 seconds B-4 Driving
Fluids and lubes
do not change oil until about 1,000 miles. fuel use best available (because my specific engine has CR or 10.5:1
Set total advance to 35 degrees max when mechanical advance is fully advanced . If you hear any pinging at part throttle disconnect variable advance and recalibrate you can also add 10% leaded race gas if you have access to it , but probably not necessary.
Engine oil you need a high zinc oil for cam Break in Some brands are Brad penn; Joe Gibbs or Valvoline Off Road Racing Oil. Do not use synthetic oil until rings are set. Red Line oil is a good choice after break in. ......

Again credit for this info is too Dave Headley of Fab Tek , any spelling and grammatical errors can be atributed to my dyslexia ;-)
Chris Velardi

Remember to build oil pressure before starting for the first time.
Russ Carnes

This thread was discussed between 26/09/2009 and 27/09/2009

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