bored and honed .044 over but looks very thin

[edfishing2]

83 Evinrude 100hp. I have all new Wisco pistons have the block bored and honed .044 over but the steel sleeve looks very thin on one side especally at the "splines" at the ports. Does anyone know what wall thickness (at this thinest splined area) is acceptable?

Does this "spline" go all the way up the OD of the cylinder sleeve walls or is it just the lower section of the original sleeve?

If too thin can this block be heated up and the old sleeve extracted. If bored to install new sleeve does the aluminum get too thin? Ie what is suggested max sleeve OD.

Does anyone know the diameter and spacing for the ports if I install new sleeve?
What is center to center distance on cylinders?

Thanks,

Ed

 

[Joe Reeves]

Re: bored and honed .044 over but looks very thin

Frankly on that engine. boring oversize .030 would be as far as I'd go. If the scoring was beyond that, I'd have it resleeved and returned to standard size.

 

[Dhadley]

Re: bored and honed .044 over but looks very thin

Whenever we bore a crossflow to .044 or .064 we recenter the boring bar on the first pass. Not many cylinders from the factory are centered but the sleeves are thick enough to allow for a correction. Sounds like your machine shop skipped that part, most automotive shops will. It'll be OK as is but probably can't be cut to .064.

Changing a sleeve in a crossflow isn't as simple like it is in a looper. The old sleeve is cut out and the new replacement sleeve is pressed in. Then the ports are traced out with a mill.

 

[edfishing2]

Re: bored and honed .044 over but looks very thin

How thin is acceptable?
If reboring just center up on the aluminum?

 

[Dhadley]

Re: bored and honed .044 over but looks very thin

It should be OK since there is still sleeve. When reboring over .030 we center up on the OD, not ID, of the sleeve itself. Most sleeves are not exactly centered and are not bored exactly on center.