Kris,
Intake bridge? What intake bridge? We don't need no lousy intake bridge
The bridge does provide some support in a forward turning motor that's true, but it isn't strictly necessary. You can gain 15% flow improvement just be eliminating the bridge. it's worth thinking about.
Single ring pistons seem to work better than twin rings above about 8k and lose some below that number. Are you sure you want to go that way? Just asking.
I'd prefer to have a pair of slightly thinner rings in a lighter piston with pegs moved probably to the space between exhaust and transfer ports.
Of course the exhaust port is still a problem unless it's bridged and widened and the outer studs are moved and.....
The best the factory motors ever did was about 130 at 10,000 RPM. Keeping in mind you gain horsepower with less frictional losses using straight cut primary's and the dry clutch.
Not a lot of help having such meager transfer area. Will be installing squish band head inserts like they do to the snowmobiles. I had very good luck with them on my TZ500/750 as you can skim cut them on the lathe and get all cylinders perfect.
With the 850 kit, and good boost porting to compliment the two transfers, their is a reasonable expectation to shoot for 150 HP at 9,500RPM. I will have to run the numbers but with the big jugs, mean piston speed will be critical.
We'll see...
There is quite a lot of metal in the transfers before you break into the water jacket and still have a convergent nozzle effect. 150 at 9500 needs a lot more exhaust area but you should get enough transfer area to support that.
If you are looking at replacement liners, might one assume that you are thinking exhaust bridge contain the ring/s with wider top eyebrows?
No the plan is an aluminum liner that will allow for Nikisil plating on the bores, rather than the traditional (read antiquated..) iron liner. The liners will need to be thick enough to allow "sub ports" for the exhaust, much like the modern vmax's and TZ's...
Being a "wet" liner the transfers can be widened and bridged as much as architecture allows but more importantly the reed boxes will be opened up
so openings can be made directly to the transfer ports.
I believe a couple of the cylinder studs can be omitted to permit a wider intake foot print.
What say you, Dave?
If there was only a way to bolt the block down at the base it sure would make it a bit easier to run the transfer boost ports but as things are now like you say the studs are going to be in the way . Here are some pictures i collected of Bretts mods he did to his big HP speed engine showing just what it takes to get the big numbers out of this engine http://draken.gotdns.com/Suzukidave/Bre ... %20engine/
Have not seen much activity from Brett in awhile? Hope all is well for him in OZ. Would gladly wash is Hillman for a year if he was willing to sell a barrel to me...
That is another thing we should be doing is running these beasts on alcohol.
Cheap and easy way to pick up 10% more power...
