Discussion in 'Engine, Fuel and Exhaust' started by 03hd4me, Dec 11, 2007.
A couple things to remember, That's a "B" engine so you need to keep the rpms down and concentrate on making torque down low with a 6000 rpm max redline, instead of roller rockers and billet support I'd spend the bucks on having the bottom end lightened, balanced and trued, upgrading the oil pump and cam support afterwards.
The Ultima 6 speed isn't that great, if a Baker is out of the budget look into S&S's new 6 speed!
NVPC has some great ideas there and I agree with the ultima not being the best to use.
thx for the info. so any insight into how to make sure the torque is where i need it and not way up in the rpms was reading something about rocker arm ratio affect cam duration thereby affect torque/hp was gonna do gear change 25 tooth crank gear to 24 tooth and 37 in clutch basket go from 3"15 to 3"37 in know the will give me the torque will it be where i need it. i was gonna then drop 6 speed in it to get a highway gear back race round town in first five gears hit the road with the overdrive. just learning myself
To start, all good 6 speed transmissions are "Direct Drive" in 6th gear! Just like a 4 or 5 speed. The point of going to a 6 speed is to give you a lower 1st - 5th so you can run a higher final drive ratio for lower RPMs at highway speed without killing you around town or in the Mts.
As far as building torque in the lower RPMs, Keep the stock intake valves and have the exhaust replaced with EVO exhaust valves and do a clean-up port job (Some head porters are calling this a street port package) You don't want to enlarge the ports just straighten out and smooth the flow, then match the head ports to the intake runners. Use a 2-1 header with longer head pipes and a larger collector like the V&H pro pipe.
For the Tw6 cam to work right it needs 10/1CR, and valve springs to match it. 10/1CR will be hard on the starter unless you have compression releases installed. In a 103ci engine It'll build lots of torque in the 2000 -4000 rpm range, just what you want.
fogot to throw in the +4 degree cam gear im adding to the cam as for roller rockers etc. i was told that with a 590 lift cam they were all most mandatory and the the rocker supports to keep everything where it belongs. Can i get by on stock rockers (what about side loading) and why do some places say their 6 speeds have 6th as an overdrive if they are all "direct drive"
oh i forgot i already have the V&H pro-pipe right now i have the torque baffle in im taking it out and putting the competition baffle in it. plus using a SE 45 mm mikuni
how best to make the 10:1 comp with flat top pistons will the duration 240' be a factor and cometic gaskets, need i mill the heads.
in terms of springs etc any ideas are SE good enough any body have feedback about beehive vs dual spring design my understanding is my cam to big for beehive anyhow
Not all the 6 speeds are DD6 some have a 1:1 5th and a true overdrive 6th, but they are of a weaker design that eat HP that should go to the rear wheel.
The .590 lift cam would benefit from the rollers and support but They are not required!! If your on a budget I'd spend the cash on the lower end, also you would lose a few ft/tq with a swap to the standard TW6 and not the TW6H, You could run 9/1CR and run about any pump gas, not need the comp. releases, much less wear and tear on the engine and only lose 5-7 ft/tq. Still get you over 100 ft/tq !!!
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