SBF Balance question.. Neautral... 28.. 50..

[Gary Smith]

Bret Velde could probably shed some light on the subject I believe he played with external balanced SBF a long time ago.

[BRETV]

Brad, we did pick quite a bit going from 50oz to 28oz, but we also changed some other things to, so not sure how much was just the change in the weight.





Bret Velde
2003 ??/SA

[Stephen & Horace Johnson]

[QUOTE=HawkBrosMav;628254]

Originally Posted by Stephen & Horace Johnson

Fortunately in the combo we are running it's never seeing over 6500 RPM we've had a stock crank 50oz motor together for going on 10 years now and have never had any issues outside of now having 1000+ passes on it we finally wore the bearing out.. Don't really need to spend to money/effort on neutral balance if there isn't any performance gain, but wanted to consider the option of if verse the cost buying the Eagle crank and going neutral. if we were having reliability issues I could justify the expense for it, but at this point the investment is simple for potential HP gains for a car that will never make the top half of the sheet on the current budget.

Additional info; were making 300-350 HP tops... not a speed demon by any means haha

Brad

also makes a difference if its stick or auto.I was turning my sbf 68-7.... I'd rather be safe then sorry

I have not had any issues with scat or eagle in my engines or the ones I have built for others ... maybe I was just lucky .....good luck

[SSDiv6]

Originally Posted by Stephen & Horace Johnson

I have not had any issues with scat or eagle in my engines or the ones I have built for others ... maybe I was just lucky .....good luck

Stephen,

It is touch and go with Eagle and Scat. I have heard that Eagle improved their machining, but some issues still linger. The last two Scat crankshafts I used, required rework.
Still, if a replacement crank is available from Molnar or Callies, that is the way I prefer to go. Everything I get from Tom Molnar is right on the money. Tom was the guy at Oliver Rods for many years and the quality of his products is outstanding and he stays behind his products.

[HawkBrosMav]

Originally Posted by SSDiv6

Stephen,

It is touch and go with Eagle and Scat. I have heard that Eagle improved their machining, but some issues still linger. The last two Scat crankshafts I used, required rework.
Still, if a replacement crank is available from Molnar or Callies, that is the way I prefer to go. Everything I get from Tom Molnar is right on the money. Tom was the guy at Oliver Rods for many years and the quality of his products is outstanding and he stays behind his products.

Not sure if it's actually enforced, but being a stocker only the Eagle and Callies cranks are legal... looking at Callies it doesn't even look like they produce the stock legal crank any more. I've run Scat stuff in all my bracket car motors with no issues. I agree all the eagle stuff I've ever bought needed to be turned to use it.. at this point I think we're just going to stick with a stock crank at 50 oz. on our budget with our performance goals it doesn't sound like this is really worth it.. we'll focus on other places to better invest our money that may be worth something as we know there are places elsewhere in the car that could use some attention. This was more of an opportunity presenting itself type situation ha

thanks for the input all

[RJ Sledge]

Brad
In your Combo a nice well prepped OEM crank will work great at 6500 rpms. Cryogenic treatment helps but it’s not a must.

Eagle steel crank 3.00 stroke neutral balanced turning 8800 for 2 years now with no issues.

Good luck.’
RJ

[Ralph A Powell]

I ran a Boss 302 crank stroked to 3.25. Pin width was 1.820 @ 2.00 dia. BME Aluminum rods 5.35 length big end width.900. Assembly was 100 percent internally balanced with a Fisher damper. Ran this combo to 9500 rpm for 3 years with no crank or Block problems. Block was a Boss 302 ( D1ZE- B service block. Bore started @ 4.030 and ended up 4.080.