RedMist wrote:Revhead, I think your going the right route for a good mid range engine. The flow work we completed on both silvertop and blacktop pointed to the silvertop as the engine to work. For much the same reason as the smallport is better than the bigport. Velocity.
Just as an indicitive I ran two silvertops one blacktop and the race big come smallport in the Bunderson.
Our silvertops produced 122 and 123 bhp at the wheels stock with a shitty exhaust and a Link LEM3
The Blacktop produced 132bhp with a considerably better tune and the LEM4.
The Race big come smallport produced 177.5bhp With the same LEM and a custom doggies danglers exhaust.
All were on dynopac chassis dynos.
When you compare the black and silvertop you have to consider the sum of the components. With all the changes and only a 9bhp increase on power there has to be some changes that acutally reduce peak power. I'm a great believer in squish and velocity. Both which are low in the blacktop. One blacktop feature I would certainly complete on the silvertop would be to increase the exhaust ports size dramatically. The silvertop's really choke on exhaust, hence Franklins (I think) or possibly CSL (I'm getting Altzhiemers) that use a bigger exhaust cam than intake cam to counter the exhaust problems. God knows why the didnt just port the bloody thing!!!
funny in cc's the blacktop attualy has a smaller port so off teh bat tehy shoudl have more velocity
you talk of teh silvertop exhaust and opening it up...been there tried that theres only 2mm of wall thickness to teh inside of teh head and the water jacket
so no you cant do that
we played a fair bit with teh silvertop head and becaue ive done that personally i can tell you some things as fact
1 you cant open up teh ex port or they will crack though
noythings proven
one of teh other forum members here spent moonbeams on toda gear..and no cigar
ewan spent lots on workign his as well...full monty and while he has great power under the curve peak was not high
revhead your making outlandish cliam that are unfounded and you have no eveidence to back them up
if you were anyone else than a mod this threed would be locked and discared because of it
im not tring to be insulting in tring to keep it nice but hell