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MG MGA - Engine Rebuild start up
|Well Guy's, Finally received 1600 block back from machine shop and got everything back together and installed last night. I expect to do the first start up this afternoon. I oil primed the engine thru the preasure gauge port. I have receved a couple versions on how to seat the rings. One guy said to run the hell out of it. Another stated to hold a fast 2500 RPM idle for 20 Min. Any insight or advise on this subject!|
|Is the cam new? were the lifters changed? If no to both were you careful to reuse each lifter in the same hole? The initial start run up is mostly for the bedding in of the cam and lifters (a fast 2500 RPM idle for 20 Min). Rings tend to wear in over time, 500 to 1000 miles. DO NOT use synthetic oil during the break in period. What oil is in the engine?|
Normally with a new engine with new cam and lifters you would: 1 Crank without plugs or fuel and with the valve cover off until good oil pressure shows on the gauge for 30 seconds and adequate oil flow to the rockers is seen. 2 start and run at 2500 for 20 min, checking oil pressure and engine temp the whole time. While running at 2500 rpm: Make sure the air flow is the same through both carbs and Ignition timing is about 28 degrees at 2500 RPM. 3 drive the car. Keep the RPMs up but not constant for the next 1000 miles.
|R J Brown|
|Sounds good RJ, The cam is not new but the tappets anf rods are. Rings and bearings are also new with the crank be turned to .020 New cam bearings were installed. As I said I did pre prime he oil as much as I could. Iam just concerned with the cylinders glazing before the rings are seated.|
|The current practice for seating rings is to do several full throttle run ups while driving. Theory is that the high forces created press the rings tighter to the cylinder wall to bed them in faster. I would use R J's method first.|
|I learned to bed the rings by accelerating for a few seconds or more, then decelerating for the same on relatively level road. My experience has been that the acceleration is as J Heisenfeldt noted, creating higher forces on the rings, the deceleration causes enough vacuum to pull oil up into the rings/cylinder walls for rinse and lube, that cycle is important to bedding in the rings. I grew up in the '50's in Tennessee mountains where rebuilt auto engines only lasted 50-60k miles, less if not broken in correctly. After a couple hundred of gentle miles, a drive up and down the mountain did the job. |
It is important to limit the rpm range in the first few hundred miles, gradually building towards the full range as rings, bearings etc seat in. Remember to check torque on the cylinder head (and run a wrench around anything else that you can reach, especially manifold hardware,) and then check valve adjustment after a couple of hundred miles, more if the get noisey.
|All others advice above is good.|
Do not over rev.
Do use full acceleration.
Do not "cruise" at a constant RPM.
A nice fun cruise along a hilly twisty route is great for you and the car. When I finished my 57 My first drive was a loop around the peak to peak highway. http://www.coloradodirectory.com/maps/peak.html
Here is a picture of a picture taken that day (shows a little dark, it was a perfect day)
|R J Brown|
|Well! Got her back in and she fired right up! Puuurin like a kitten. Ran around the block a few times and shut her off and to my amazement only one tiny drop of oil the size of a pin head hanging on the back plate! Not the pint I was use to :) The 1600 has a lot more power and tourqu than my 15 had. Good times are here again!!!
|Bill, I didn't know you were a blonde!|
|Mark J Michalak|
|That the free help! I think she has visions of driving it now that she just got her license!|
|Bill, don't tell her how the handbrake works, she will never get out of the driveway.|
Glad every thing worked out with the new crankshaft.
Your car looks great.
|Nice car, Bill and to your "help". |
Congratulations on the recovery, we all learned quite a bit from the posts.
Congratulations on your rebuild. When you adjust the valves hot, insure that the pushrods are rotating in their seats. This is an indication that the lifters are also rotating, and this is needed to insure that your cam and lifters don't prematurely wear.
|Well Cheers to all of you from my wife, children, and I! without the help of kind people on this forum, and of course Barney's Site, I would still be turning wrenches. Special thanks to Gary for the wonderfull crank,and RJ & J. And a special note to Russ on his great taste in colors!|
This thread was discussed between 20/08/2008 and 22/08/2008
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