Topic: CB650 head swap vs porting CB550 head

[Flanker08]

Wanted to gather opinions from the experts on here. I'm in the process of building 2 bikes. One is a CB 550 and I'm planning on making this a retro build. The other is a 650 engine bored to 674 and placed in a CB500 frame and made into a restomod build.

I have purchased a MR stage 2.5 head for the CB650 engine. Thus I'll have a spare stock 650 head and cam.

My question is...ok the cb550 would I be better off going the route of a CB550 head ported by MR with a cb650 cam(wasnt trying to go wild on this engine and bore it over) or would I be better off going through the trouble of swapping the stock 650 head/cam onto the cb550 engine.

I'm thinking a stage 2 ported head and stock cb650 cam plus CR 26 cams would be the easier option vs doing the whole head conversion.

Opinions on either option?

Thanks

Drew

[Bankerdanny]

I don't believe the 650 head is a direct swap to the 550. There's a recent thread on this subject. It is FAR easier to swap a 650 engine than to marry a 650 head and 550 engine.

[flatlander]

throw the 650 cam in the 550 and be done with it. you'll already have a powerful combo with the modded 650 engine in the 500 frame. anything you do to the 550, won't match that anyway.