question about switching heads

[surfjunkie]

i remember hearing that some people used to put 650 heads on 701 engines to get a cheap bump up in compression.

is that correct?

if so, can you do the same with a 701 head on a 760 engine??

forgive me if this is a) dumb question or b) general knowledge and been covered ad nauseum.

i'm really just wondering if i can put my spare 701 head on a 760 engine just to see if the engine is good.

thanks

 

[Matt_E]

Try it out and let us know. :biggthumpup:

 

[Cliff]

all you would be out is a head gasket if it didnt work.

 

[surfjunkie]

see, i dont really know what i am doing when under the hood, so i envision putting on that head, hitting the start button and having the engine desintegrate in front of me.

 

[Cliff]

i wouldnt think so but i would get a few more opinions

 

[Waternut]

If you're really worried about it, do a search on how to check your squish to make sure you're ok and then check compression.

 

[Matt_E]

You might think about measuring dome diameter and comparing it to piston diameter.

 

[surfjunkie]

haha ya'll dont know who you're talking to.

i can squish a bug and polish my dome but thats about it.



i'll wait to see if someone has a definitive yes or no. but thanks for the replies.

 

[Cliff]

alrighty then, the more i think about it, the answer is no. the domes and squish would be off. it may crank but i wouldnt expect it to last to long.

 

[Matt_E]

haha ya'll dont know who you're talking to.

i can squish a bug and polish my dome but thats about it.



i'll wait to see if someone has a definitive yes or no. but thanks for the replies.

Alright: a 650 has a 77mm piston diameter.
A 701 has 81mm piston diameter.
A 760 has 84mm piston diameter.

The respective heads to go with each size do go over the respective diameters, but only by so much. I don't know how much. It's quite possible that what you're wanting to do works.