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[SPIDERMAN]

I'm running 257 cams in my 110 dyna...even in a light bike it helps to keep revs above 2700...long cams are great if you don't mind revving

ahhhhhhh, errrrrrrrr, ummmmmmmmm   2700 is revving ? 

I usually keep my tach in the 3500 - 4500 range


B B

[skyhook]

no I mean below 2700 is soft with that cam even at 10.7 compression

[CVO103]

I have decide to go whit SE-251 cams. I understand that the cam lift is ok.
Piston 22483-04 if it possible? Does this fit? I have read the post that Dawg have sent to this forum? ( maybe hi is older and learn (become wise) by experience)? i don't now.
Milling the heads 30 thoue? If i have to do it.
Milling the head 30 (thoue) and the piston 22483-04 compression must be to high? Over 11.0:1 i think?

30 (thoue) it is about 0.8 in millimeters?
Regards


Jan-Olof

[DCFIREMANN]

Yes those are the right pistons. If you are going to order them, order  +.005 and have the pistons fitted to the cylinders.

Be Safe

THE DAWG

[Classic Beast]

I have decide to go whit SE-251 cams. I understand that the cam lift is ok.
Piston 22483-04 if it possible? Does this fit? I have read the post that Dawg have sent to this forum? ( maybe hi is older and learn (become wise) by experience)? i don't now.
Milling the heads 30 thoue? If i have to do it.
Milling the head 30 (thoue) and the piston 22483-04 compression must be to high? Over 11.0:1 i think?

30 (thoue) it is about 0.8 in millimeters it is best for me

Regards

Personally I wouldn't mill the heads as over 10.5/1 compression your asking for trouble on the street besides with the quench area on these 103+ heads that are designed to match the pistons the milling will interfere with this. With the 257 or 258 cams it would be better since the cam timing will take advantage of the higher compression as they both have more duration and overlap than the 251 although the 251 has higher lift. The 251 would have better low to midrange power. 22484-04 .005" o/s (pair). is the part number for the oversize pistons.


Jan-Olof

[SPIDERMAN]

For what it's worth, every time I've had a set of heads milled, I've developed issues with the cylinder studs pulling out of the cases at some point down the line. I do not personally recommed this practice anymore to anyone concerned with the longevity of their motor.

just my $0.02

B B

[porthole]

Yes those are the right pistons. If you are going to order them, order  +.005 and have the pistons fitted to the cylinders.

just cleaning up the ports, doing a good 5 angle valve job, and equalizing combustion chamber volumes. 

In days gone by (automotive world) i have done a few valve jobs, all dealer work.

Typically they were 1 angle. If we were doing the work for a "special" reason then I would do a 3 angle, and 5 angle wasn't in the picture back then.

But seeing the way heads, pistons and valves looked after thousands of miles, I am curious as to the long term benefits of going through the trouble of a 5 angle or fitting the pistons exactly to the cylinders.

Does it really continue to be an effective 10-20-30,000 mile down the road?

[DCFIREMANN]

ABSOLUTLY!!!!!

Be Safe

THE DAWG

[Classic Beast]

There is nothing wrong with a 5 or even 7 angle valve job the problem comes into play in the pursuit of maximum Horsepower where the seat is too narrow or too far out to the edge of the valve instead of in the centre. In days gone by there was also a 1 degree interference angle that helped with sealing but with todays modern machining tolerances this ususally is not needed anymore. Properly done heads give "free" power, reduce detonation and increase efficiancy without any downside. The ccing of the combustion chambers can dramaticly affect smoothness since if not matched you can have a difference in the combustion ratio of each cylinder. A change in the design of the combustion chamber can also be an advantage since many modern heads primary design is to reduce emissions. If power and or efficiancy is the primary goal the cylinder head will have a different design. If you compare the EVO bathtub design to the open chamber twinkie design you will see a larger quench area on the bathtub which helps with combustion chamber turbulance and more even burning. Check out Branch Okeefe or some of the other shops doing the proper research on what makes heads work.

[CVO103]

Now i have finished my building of my 103" inch engine. I used 22483-04 piston, cometic 0.030 gasket, SE-251 cams, kit 29877-06 and new bearings.

The result is 101 horsepower and 150 Nm torque  (111 ft-lbs?)