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Head Swap
- CoolerKing
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15 Jan 2016 13:00 #706823
by CoolerKing
1978 KZ650-C2
1976 KZ400D-3 (sold)
Head Swap was created by CoolerKing
I recently picked up a 1980 kz750 engine to swap into my 78 kz650. I posted about this over on kz650.info and it was suggested I throw a 650 head on for added compression... While trying to research head swaps I came across the possibility of using a ZR7 head. Would there be any benefit to switching to a newer ZR7 head vs the stock one? I'd have to convert to an electronic tach but that's not a huge deal. I haven't even touched this motor short of pulling it off the truck so I don't know the current condition.... I can only imagine a 20xx year head would be better than a 35 yo part... Any suggestions or experience in this??
1978 KZ650-C2
1976 KZ400D-3 (sold)
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- SWest
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- 10 22 2014
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15 Jan 2016 13:20 #706825
by SWest
Replied by SWest on topic Head Swap
Valve guide seals at least.
Steve
Steve
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- Nessism
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15 Jan 2016 13:31 #706827
by Nessism
Replied by Nessism on topic Head Swap
The ZR-7 head has what they denote as the "bathtub" shape. I think this is an advancement over the earlier head. What I don't know is if that head would work with the early pistons, which are different (lower compression). At the end of the day you are going to have to buy more parts, fiddle fart with figuring out compatibility, all for a marginal bit of extra power. Some people feel this extra work and expense is worth it, but not me. I'd focus on cleaning up the engine you have and change the top end gaskets and seals. Doing that is like money in the bank.
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