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Discussion Starter · #1 ·
looking to remove pros cons 20 - 25 gals of fuel a year will i beable to go a season on a piston oiler holes ok left open according to allan @ ct he said it would be fine drag situation will i notice a big differance with it gone compared to being really thin thanks
 

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looking to remove pros cons 20 - 25 gals of fuel a year will i beable to go a season on a piston oiler holes ok left open according to allan @ ct he said it would be fine drag situation will i notice a big differance with it gone compared to being really thin thanks
Long as you didnt widen the port any more than stock I dont see why it would be a problem.
The exhaust bridge is more or less a guide to help push the rings back in their grooves. It can also be a big problem if not releaved after a bore & fit of a new piston.

If theres some way you can fill those oil holes in the piston I dont see a problem with that. Welding would be the best but may deform the piston when doing so. JB Weld would fill them, but after awhile the oil & heat would have some effect on it.
Wouldnt hurt to add some oil holes in the piston in the areas between the aux exhaust & main exhaust ports just to lube those small bridges.

Did you ask allen about an oval port cylinder, ?? because they do have them.
If you take the center bridge out, when you cut the exhaust port, make the roof more round & not flat so to allow the rings to easier seat back in the grooves.
Neil
 

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I had an esr 310 with no bridge. I broke the ring lands out of the piston twice. Some said it was detonation, some said it was heat, and some said it was hanging a ring in the exhaust port. It would break the entire area in between the rings from one side of the exhaust port to the other. The third piston never gave any trouble, but I changed to race gas and ESR may have chamfered the port a little more. They said they didn't chamfer it, but it looked like they had. I've ran race gas ever since.
 

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Discussion Starter · #4 ·
I had an esr 310 with no bridge. I broke the ring lands out of the piston twice. Some said it was detonation, some said it was heat, and some said it was hanging a ring in the exhaust port. It would break the entire area in between the rings from one side of the exhaust port to the other. The third piston never gave any trouble, but I changed to race gas and ESR may have chamfered the port a little more. They said they didn't chamfer it, but it looked like they had. I've ran race gas ever since.

good power improvement ? im wondering if i shoud risk reliablity but this bike is set up for 300 dirt drags or 600 sand drags at silver lake
 

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Well, when your drag racing now, its who ever is the biggest, badest & spent the most money to go fast, so if it will last a day then thats what you got to do to get the job done.
On the other hand, if you want it to last a long time, then you got to ask yourself if dragging is the type of racing you want to do.
I've been around most all types of racing over my years & drag racing is one type that big pockets & a fresh engine is whos going to win just about every time.
Neil
 

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good power improvement ? im wondering if i shoud risk reliablity but this bike is set up for 300 dirt drags or 600 sand drags at silver lake
I can't say if having the bridge removed was an improvement because I bought the 310 kit new from ESR and that is how it was already. I think they have quit doing that since then. I can say that my 310 with TRX9 port and TRX5 pipe ran really good mid to top. It didn't have enough bottom for me so I sold it and went to the set up that I have now.
 
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