How do you get more Hp out of a ROW 3lt?

[slow car]

Hi ,
Now the end of race season is here ,i am wanting to freshen up and maybe up spec my 83 3lt row SC running 40 webers,964 cams, programmable MSD dist and 1,1/2" tuned headers into straight through resonators. Approx 275 HP at flywheel.Running 98 Octane fuel.

Would like to get 320 usable Hp?
What options have i got without changing to twin plug and still keeping the 40mm webers if possible?

Going to 98mm with 10.5 and a cam/porting ?
Any real life success story's and how to,s would be great?
The car is used for Road racing ,autocross,and track days, so need a all round motor.
Not used as a street car.
Thanks for any help.
John

[toddu]

Got 300 out of mine. 98mm 10.5, mods cams, 3.2 heads and 46 PMOs. Oh, and twin plug (which you will need if you go 98/10.5).

Todd

[Henry Schmidt]

320 hp is a stretch for a 3.0 or even a 3.2. To get a number like that you have to spin it.
40mm Webers won't do for the rpm you need.
I would clean up the Webers and sell them to buy a set of PMO 46 or even 50.
The RPM (7600-8000) will require better rods, higher compression.
Think about twin plugs and great valve springs as well as porting to match. (40-41 mm)
If you want it to last, shuffle pin and install the best oil pump you can afford.
Because of your desired HP, I would make it as big as possible. I like the LN Nickies for their 100 cylinders. 70.4 X 100 will yield a 3.3 short stroke.
Beyond that, cam selection will be critical. I would look to John Doughtery @DRC for advise but DC80 at a minimum.
Cheers

[lindy 911]

How did you determine you have 275 rwh? From what you described I would guess more like 230. The reason I mention it is because your goal horse power might not need to be what you think or are asking for. I got about 245 rwh from a 3.0 with 10.5:1, twin plug, '78 SC heads, GE 60 cams, headers and 46 Webers. At that power level it ran extremely well. Carbs were set up well and ran about 26 degrees total timing on 98 pump gas. That car would spin 315-30-17 tires in second gear without banging the clutch. And slide, oh boy!

[3literpwr]

Originally Posted by lindy 911

How did you determine you have 275 rwh? From what you described I would guess more like 230. The reason I mention it is because your goal horse power might not need to be what you think or are asking for. I got about 245 rwh from a 3.0 with 10.5:1, twin plug, '78 SC heads, GE 60 cams, headers and 46 Webers. At that power level it ran extremely well. Carbs were set up well and ran about 26 degrees total timing on 98 pump gas. That car would spin 315-30-17 tires in second gear without banging the clutch. And slide, oh boy!

Where are the GE60's running out of steam at? I'm looking at cam selection now for my 3.0 rally build and was thinking DC60...

[lindy 911]

GE 60 in this combination makes great set-of-the-pants torque. They start to sign off at about 6700 but will pull to 7000. They hit pretty hard at around 3800. I thought what was most impressive is that below 3500 it's hard to tell it's not stock.

[slow car]

Hi Indy 911
The 275 is Engine HP you are correct the RWH was around 230.

[lindy 911]

Duh! Now that I reread you original post it says right there "275 at the flywheel". Sorry bout dat.