- Location
- Sydney
Not a close a match as I thought
Misaligned sleeves/ports
- Thread starter superjetincairns
- Start date
Not a close a match as I thought
- Location
- Sydney
For the record a JM ported 718 went a lot harder than this , but as far a stocker it went better than most
yeah Bar jumper those look about as nasty as my "6 6" (or "9 9") 61X cylinders. Maybe the rumour that the "0 0" stamp is the best sleeve-cylinder port match is a myth. Or maybe the quality control guy with the stamp was dozing on the job. Anybody else got numbers/pics? I think TheBuzzard is correct that matching these up by removing some of the material in the cast alloy can only improve flow and performance.
imo when raising the alum to match the sleeves
the engine acts like blowdown is shortened
this can make for a muddy and rich bottom end
then you need to raise the export to lengthen the blowdown back again
but you also will need to increase compression
use better and more aggressive timing curve
pump and prop tuning will now need be done to match the different power curve and hp output
the engine acts like blowdown is shortened
this can make for a muddy and rich bottom end
then you need to raise the export to lengthen the blowdown back again
but you also will need to increase compression
use better and more aggressive timing curve
pump and prop tuning will now need be done to match the different power curve and hp output
Freakrider
X247
- Location
- Tampa Bay area
A local engine builder does not touch the roofs of the transfers on 61x cylinders for reasons said above by Dartman. You can PARTLY match the aluminum to the sleeves by widening the transfers.
- Location
- the jetski grave yard
to the untrained eye, you can barely tell a 00 cyl from a 12/12, but even a slight difference equates a noticeable power difference. and when you put a motor on the degree wheel to measure port timing, you read it at the sleeve port opening, not the aluminum casting inside the port window. when porting transfers, you direct the charge up and to the back of the cyl.
Last edited:
Quinc
Buy a Superjet
- Location
- California
Some good advice here on transfer port matching to the sleeve. I think for now I will tread carefully by doing nothing except putting it back together now that I've repaired the broken head bolt. Never had this '94 61X running or in the water so itching to see what it's like compared to my '14 62T stocker. Thanks all for your valuable contributions. Anyone got a photo of the transfer ports on a "0 0" stamped cylinder they'd share with us?
- Location
- the jetski grave yard
post #21