cases can you mix an match

[98blaster]

Well i got a call today from my friend, which happens to have one of my blasters in his garage, long story short his uncle decided to ride it an the chain blew off an broke the engine case.

Question is can you mix an match cases or are they matched set?

 

[waffle429]

What do you mean by matched set? Like, is the bottom end (cases) a matched set with the top end (cylinder)? If so, no, it doesn't matter.

 

[woodrow wilson]

I think he's talking about mixing n matching left n right bottom cases.. I dont see what it would hurt as long as you lapped then just to make sure there flat..

 

[Awk08]

case halves are probably a matched set originally, but can be mixed if both sealing surfaces are are lapped flat

 

[98blaster]

Awk have you personally used unmatched cases? Cause i trust you an if you have personally done it then im good ill do it

 

[Awk08]

Awk have you personally used unmatched cases? Cause i trust you an if you have personally done it then im good ill do it

I have never broken a case myself, but years on here i've seen plenty of guys buying/using a left side case to use with an original right side.
if both are lapped flat, it's perfectly acceptable to do

 

[Blaaster]

The cases are cast items and are machined to size, as far as I know they are assembled and line bored as a matching set.

I could be wrong but I feel that you can get two unmatched cases and use them without any problems....... I do know that is has been done countless times.

Give KOR a bell he will put you on the right track.

 

[Wifesblaster]

I have used unmatched cases. Do what Woodrow Wilson and AWK said and lap them.

 

[98blaster]

Yes i was thinking that they were machined together as well, I use a different engine builder ill call him tonight an see what he says

 

[Fast6hand]

I used a left side that didn't match the right on my build. I lapped them in my garage. Big piece of sandpaper taped on glass top. Moved cases in figure 8 until sharpie was gone. Sharpie was on the mating surfaces. Once all gone cases are lapped. Worked well. I have no known issues until this point.

 

[Blaaster]

It is not the case mating surface that concerns me, but the boring of the main bearing crankshaft journals.

As there are only two bearings and they being of the ball variety, there should be a fair amount of leeway if the journals were not parallel.

Line boring is done to make sure that the crankshaft bearings are perfectly aligned.

As stated before, mismatched cases have been used many times without any problems.

 

[98blaster]

It is not the case mating surface that concerns me, but the boring of the main bearing crankshaft journals.

As there are only two bearings and they being the ball variety, there should be a fair amount of leeway if the journals were not parallel.

Line boring is done to make sure that the crankshaft bearings are perfectly aligned.

As stated before, mismatched cases have been used many times without any problems.

The crank main bearing bores are what concern me, im a mechanic for a living and most things that have two piece cases or housings are usually matched set, as there machined together. But if its been done many times before then I guess thats what illhave to do, this engine only has to last another couple months till iI can get my stroker engine finished then its coming out

 

[Larry's Shee]

Look at any Blaster parts flitch, cases are listed seperatly. Might be one of the few, if not only, that way. Any others i've looked at are only sold in pairs.

I saw a cut-away of a case and it appears they use like a precast/machined insert for the crank bore.

 

[Blaaster]

If the bearings were slipper type or roller type I would be worried, but ball type have the advantage of some lateral movement and are able to realign to correct the mismatch.