MS II with New rings?

[ricardobready]

I don't know if this is the right place for this post. Sorry if its not. I need to know if it is safe to install new rings before installing the megasquirt? If I have problems, will this cause the rings to not break in properly?

I have a 383 stroker that I bought used (for $800.00 including the 4x4 truck it was in) and am installing a different roller cam, new bearings and a ported TPI, with world S/R Torquer heads.

Thanks in advance for your advice.

Ricardo

[fury fan]

I always err on the side of caution, so I would avoid installing new rings and then installing MS. Rings are somewhat sensitive to a proper break-in for best performance, and you don’t want to take any chances on fuel washing down the cylinder walls or something like that. As the MS manual says, it is often best to install MS on an engine that has already run and has been proven.

However, if you are skilled at EFI tuning and feel confident that you can get the fuel curve fairly close with no hiccups, then you’d probably be OK.

Here’s an article I found that is interesting. Regardless of whether somebody agrees with his procedure, it does seem to have merit.
http://www.ktm950.info/how/breakin/engine_breakin.html

[ricardobready]

Interesting article, seems to have some merit. I did a compression test prior to removing the engine and it was about 180 pis all around, with a compression ratio of about 9.5 to1. There was no appreciable ridge at the top of the cylinders and I removed most of the carbon from the top edge before carefully removing the pistons. I have the option of reusing the old rings, as I have carefully labelled each set as to their location, and none are broken, as I used the proper tool. Just have to get the machine shop to check the piston to cylinder clearance. The crank endplay was 0.048 inches, so the rear thrust bearing was toast. Just started to scrape the main caps but I think they are ok. The crank just needs a polish I think. I think I caught it just in time before the block and crank were scrap. Anyway, sorry for the rambling. Thanks for the suggestions.

[devastator]

I strongly advise against breaking in a cam with MS until you have it running very well. IMHO, you should get a few miles on the engine before you install and tune MS.