Performance Gain/ Reliability of kit gasket on bone-stock motor

[Daytona.Scott]

Good morrow gentlemen!
Do any of you guys have experience installing a kit gasket on the stock engine without any valve / spring / cam / crankshaft replacements?

I have been doing some research and it seems like exhaust valve is a weak point on 675 (look up sportrider daytona build). Is there significant performance gain from using a kit gasket or is it just 1-2hp gain at max?

Would running a race fuel (VP U4.4) help with stabilizing the engine?

My bike is getting race alternator installed and I was curious as if it's worth getting into as gasket itself is not that expensive.

Cheers

[wavrdr]

Valve job, head mill(.010), .065 gasket, degreed cams, and u4.4 picked up 20 whp on my bike....

Base pull was 98whp, last pull was 119.85...

[jdgun_13]

Originally Posted by wavrdr

Valve job, head mill(.010), .065 gasket, degreed cams, and u4.4 picked up 20 whp on my bike....

Base pull was 98whp, last pull was 119.85...

HEY This is my winter project!
What accompanying mods did you do?
any chance i can get your cam timing specs, was told stock is good?
also what adjustable cam sprockets did you use?

[Daytona.Scott]

Originally Posted by wavrdr

Valve job, head mill(.010), .065 gasket, degreed cams, and u4.4 picked up 20 whp on my bike....

Base pull was 98whp, last pull was 119.85...

Hmm... I am pushing 111rwhp on stock gas with full Akro system with stock sprocket...
Also my friend who has FMF pipe with sprocket one down front one up rear was pushing 111rwhp, but Akro's curve was much much smoother.
FMF was very linear (just bit fuzzy) upto some low-mid RPM and it really picks up, but again smooth. In terms of drivability, Akro was my choice.

In terms of valve job and degreed cams, are they allowed by the supersport rules?

Also are you located by Easy Coast by any chance? I am looking for a good engine builder...

[jdgun_13]

Originally Posted by Daytona.Scott

In terms of valve job and degreed cams, are they allowed by the supersport rules?

Also are you located by Easy Coast by any chance? I am looking for a good engine builder...

All the above mentioned is supersport legal..
send yoru head off to hordpower, also adjustable cam sprockets from them, kit head gasket from any triumph dealer or online.
As for a good engine builder by you, not sure where you are in NY, but i would highly recommend Marc Rozema http://www.markbiltracebikes.com/Markbilt/About_Us.html

he did my 05 636, 121rwhp on pump gas... after his head work and a retune lets just say more than what i listed above.

[antirich]

Originally Posted by wavrdr

Valve job, head mill(.010), .065 gasket, degreed cams, and u4.4 picked up 20 whp on my bike....

Base pull was 98whp, last pull was 119.85...

Well, all but the U4.4. It's VERY good stuff, and probably about 5HP of his results with the proper tune. Just that I can't justify the cost and the PITA factor of draining your tank.

But, it sure smells good on the grid :-)

I also like when people use it, for I grab their old cans for oil storage

[antirich]

If you're pulling the head and going to top end power, i would recommend the kit valve springs. Just note, that they only good for one season (as with most valve springs).

I'm trying to get APE in California to try an develop a set of race springs for the 675. Should be half the cost of the kit springs, I hope.

They also make a stronger spring retainer as well, but not for the 675 (yet)

Oh, and Markbuilt did my head re-assembly after I F'd up the valve shims. Dynoyed at 123 RW with the rev limiter stuck on 12K. We figured another 5HP is there once I figure out the issue with the rev limiter. Pulled really strong on the track, but hitting that rev limiter was not fun.

Pump gas as well.

[Daytona.Scott]

Originally Posted by antirich

If you're pulling the head and going to top end power, i would recommend the kit valve springs. Just note, that they only good for one season (as with most valve springs).

I'm trying to get APE in California to try an develop a set of race springs for the 675. Should be half the cost of the kit springs, I hope.

They also make a stronger spring retainer as well, but not for the 675 (yet)

Oh, and Markbuilt did my head re-assembly after I F'd up the valve shims. Dynoyed at 123 RW with the rev limiter stuck on 12K. We figured another 5HP is there once I figure out the issue with the rev limiter. Pulled really strong on the track, but hitting that rev limiter was not fun.

Pump gas as well.

Oh dear te he he. You know what, my friend has been working with Mark for a while te he he he (that's where he got his 675 tuned)... I also got my 675 tuned there :) great stuff... Mark also installed my attack rear sets when he did the dyno.

However, attack has a design flaw: few of the screws are too short. I have seen three separate Daytonas (including mine) whose Attack Rearsets connecting bolt just came loose on the track...

Mark fixed it up for me for free when I popped by his shop between sessions.

So the valve strength is not an issue?

[antirich]

I think most of the failures I seen/read about where retainers and springs/spring pockets. At high RPM, the valves can float without proper tension. But to be honest, this is true with most modern race engines.

But the point to make is 'race engines'. These are motors that spend most of their time above 12K, and are pushed way beyond that. In other words, the more you rev, the more stress the valve train is under.

Same holds true with rod bearings. Valve train, rod bearings and rods are typically goes when a 675 blows up. On the other hand, pistons and cranks seem to hold up just fine. Your results and millage may vary ;-)

I really don't think this is a major issue with 90% of the track day or amateur racers out there. Just those pushing the limits or have warn out motors.

I also believe that most amateur racers don't refresh their motors as often as they should. Even Triumph states that their race kit springs should be replaced each season. It's the whole "a light that burns twice as bright will only last half as long" theory.

[Daytona.Scott]

Originally Posted by antirich

I think most of the failures I seen/read about where retainers and springs/spring pockets. At high RPM, the valves can float without proper tension. But to be honest, this is true with most modern race engines.

But the point to make is 'race engines'. These are motors that spend most of their time above 12K, and are pushed way beyond that. In other words, the more you rev, the more stress the valve train is under.

Same holds true with rod bearings. Valve train, rod bearings and rods are typically goes when a 675 blows up. On the other hand, pistons and cranks seem to hold up just fine. Your results and millage may vary ;-)

I really don't think this is a major issue with 90% of the track day or amateur racers out there. Just those pushing the limits or have warn out motors.

I also believe that most amateur racers don't refresh their motors as often as they should. Even Triumph states that their race kit springs should be replaced each season. It's the whole "a light that burns twice as bright will only last half as long" theory.

That sounds like a pain... I am kind of being turned off by kit gasket :) On the other note, would racing fuel such as VP4.4 increased the compression and lead to more engine wear and tear? I just don't understand where all those extra hp's produced by race fuels come from.