760 ported top end recomendation

cookerq62

cookerq62

Life's Been Good
Location
Upper Bucks, PA
I picked up a 62t cylinder from a 760 raider. I want to put together a topend for my sj. My cases (ported 62t) are already cut for the bigger sleeves. What would you guys recomend I do?? I know its a broad question but I really have no directionas what I want to do.
 
Mouthfulloflake

Mouthfulloflake

ISJWTA member #2
Location
NW Arkansas
wet wolf posted his mod a while bacl, it was something like this:

Back the cylinder, push the sleeves out, deck the cylinder, push the sleeves back in but further down, gets the Exhuast port timing closer to, or equal to 61x specs, so it wont be a TOP END engine.

and then port, and match the rest.

He posted his price, I dont want to quote in case my memory is wrong, but I remember thinking it was a BARGAIN.
 
D-Roc

D-Roc

I forgot!
Location
Dirty River Rider
can you get different sleeves (big bore 61x?) to press into the 62t as an option? or what do you do about the sleeve being lower than the jug? decking it would make the pistons go to high right? i too would like to build a big bore this winter say like 753 or maybe 771cc using some 85mm flattops? i have a 61x and it has sportport already done so i want to know if i have any options with this jug or do i look for a new one. What are our options folks. what works well for the freestyle 760 motor. thanks in advance.
 
SUPERTUNE

SUPERTUNE

Race Gas Rules
Location
Clearwater Fl.
If your going to use a 62T cylinder, just machine the bottom of cylinder, mild porting as to not raise any ports, then use an ADA head and cut domes to match for compression ratio and squish clearance. That's the least expensive way to make big gains using 62T cylinder on a budget, for freestyle that is.
Chuck 'SUPERTUNE' Quenzler III
Team Scream Racing
1988 Carroll St.
Clearwater, Fl. 33765
(727)442-7700
 
cookerq62

cookerq62

Life's Been Good
Location
Upper Bucks, PA
The sleeves are already below the casting on the exhuast port and the casting is below the sleeves on the transfer and boost ports. Has any one milled the bottom of the cylinder and used stroker domes or a spacer plate on the top of the cylinder? I know for a freestyle/freeride portjob the exhaust gets opened up but not raised. What gets done to the boost port and the transfer ports? Are there any other tweeks like increasing or decreasing case volume or changing the angles of the ports?
 
R

robertg

Location
Winnipeg Manitoba
SUPERTUNE said:
If your going to use a 62T cylinder, just machine the bottom of cylinder, mild porting as to not raise any ports, then use an ADA head and cut domes to match for compression ratio and squish clearance. That's the least expensive way to make big gains using 62T cylinder on a budget, for freestyle that is.
Chuck 'SUPERTUNE' Quenzler III
Team Scream Racing
1988 Carroll St.
Clearwater, Fl. 33765
(727)442-7700
Click to expand...
Wouldn't it be easier to machine the cases on the base gasket surface?
 
cookerq62

cookerq62

Life's Been Good
Location
Upper Bucks, PA
robertg said:
Wouldn't it be easier to machine the cases on the base gasket surface?
Click to expand...

Possibly, but not for me since I don't want to split the cases if I don't have to. I'm hoping to put this together for a rainy day. My motor is pretty fresh and I'm running low compression and the stock ignition so hopefully it will last me. I want to stick with a single carb and pump gas with this new topend. What are the trade offs between more timing Vs. more compression when staying with pump gas?
 
R

robertg

Location
Winnipeg Manitoba
Matt_E said:
But then you can use those cases only with those cylinders.
Click to expand...
If you machine the cases you could use them with any cylinder. You just have to keep they cases and head together.

I would think machining the bottom of the cylinders would be a lot of work because you would have to remove the sleeves first.

I wonder how much you could lower the cylinder? It's good for low end if you lower the exhaust port but what does lowering the transfer ports do?
 
cookerq62

cookerq62

Life's Been Good
Location
Upper Bucks, PA
robertg said:
If you machine the cases you could use them with any cylinder. You just have to keep they cases and head together.

I would think machining the bottom of the cylinders would be a lot of work because you would have to remove the sleeves first.

I wonder how much you could lower the cylinder? It's good for low end if you lower the exhaust port but what does lowering the transfer ports do?
Click to expand...

I already have the sleeves out since one was chipped. All you need is a grill or an oven to get them out. How much can I take off the bottom of the cylinder before the ring will pop out?
 
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