Mixing cases

[Rickster]

Why is it a bad idea to mix cases from different engines? i.e. top of one 62T to the bottom of another 62T?

 

[MikeB/Mako Mike]

Most parts are put together and then machined to specs as a set

 

[Rickster]

Well, this is the argument that i have heard, but I seriously doubt the factory machines the cases to match.

Beside, what is there to machine, just the mating surfaces? It's not a problem putting a new crank in a set of old cases.

Not arguing with you, just trying to get my head around it. (which aint easy)

 

[waxhead]

i have done it before
but i checked the cases to make sure the tunnel was round
well actually is should be slightly oval for the crush
it was fine
other than that you could get them linebored

 

[Ottis]

mixed cases

I've mixed cases on two engines so far, with no ill effects. One was on a friends 98 sj, he was too cheap to buy new cases and I took a bottom off of a 650 I had lying around. second, I had a damaged 760 case,(bottom) and used another 650 bottom, it's in my blaster limited and has worked fine for two years now. I'ts something I wouldn't do all the time and if I was building a lamey or something expensive, I wouldn't use them

 

[QJS]

I believe the cases are Line Bored as one unit hence they need to be treated as one unit.
Chris.

 

[yamaslut]

Don't do it!!!!!
Cases are not designed to be mix matched....
this is advised by many top engine builders

 

[Freestyleriverrat]

I was about to do it but was told by many that it was a bad idea, and it is a big no no if you are building a higher HP motor. You can get away with it if it is stock motor, but not much more.

 

[ketsair]

I believe the cases are Line Bored as one unit hence they need to be treated as one unit.
Chris.

that's what i've heard too

 

[Rickster]

Don't do it!!!!!
Cases are not designed to be mix matched....
this is advised by many top engine builders

That is why i posted it here, to hear from the experts... I have heard it before with 'I was told by somebody you shouldn't' but never got a reason.

Line boring sounds like a good reason not to on high HP engines...:biggrin:

 

[Matt_E]

Don't do it!!!!!
Cases are not designed to be mix matched....
this is advised by many top engine builders

The question here is what engine you're building. Most top engine builders say "Don't Do it" probably because you're talking about a high performance build.

An OEM/simple performance engine probably won't see any ill effect.

 

[waxhead]

you can always line bore the cases again

 

[QJS]

I don't understand how you could Line Bore the cases again, if you did the crank would be loose.

 

[MikeB/Mako Mike]

I believe the cases are Line Bored as one unit hence they need to be treated as one unit.
Chris.

They are.

 

[sflsurfrider]

so what are the ill effects? will the engine leak between the case halves? will the crank fit too loose or tight? ive seen mismatching done on a few different engines with no problems.

i think that what is meant by it being a bad idea to mismatch is that it is a better idea to NOT mismatch.

 

[yamaslut]

That is why i posted it here, to hear from the experts... I have heard it before with 'I was told by somebody you shouldn't' but never got a reason.

Line boring sounds like a good reason not to on high HP engines...:biggrin:

pick up the phone... call someone

 

[Rickster]

Don't get me wrong, I'm not looking to build a new engine, as I just bought a 62T with ADA girdled head and msd ignition, so I'm good for now.:biggrin:

I was just following the thread on another site, and new that the x-H2O gang would give me the straight scoop for future reference.:Banane01:

I'll get waterfreaks advise over a few CL's this weekend...:27:

 

[waxhead]

if you line bore then you are just line boring the hole the same size

if there is an issues where they are bigger tha you would not be able to use them
you can get them chaecked and measured

I would not do on a high output engine
it may work but then again it may not and if you have dollars in there then its going to be an exp maybe

 

[yamaslut]

if you line bore then you are just line boring the hole the same size

if there is an issues where they are bigger tha you would not be able to use them
you can get them chaecked and measured

I would not do on a high output engine
it may work but then again it may not and if you have dollars in there then its going to be an exp maybe

who has the money for expensive maybes????? I know I dont
:biggrin: