I've been holding off posting anything on the dyno testing of my 331 cu. in. motor because it's still ongoing. We have only done 2 pulls to 5,000 RPM and still are trying to dial in the A/F ratio and timing. The motor seemed to like more advance on the first pull which was 42 degrees all in at 2950 RPM making 5.5 psi boost at 5000 RPM with 10% under-drive pulley set up. We have changed the secondary jets (bigger) and and have modified the power valve restrictors, but something seems to still be holding the motor back. We will be doing more testing today. We have burned up a few O2 sensors, but they have been very helpful  in determining how each cylinder is burning.

  Ron Lane,  Meridian, ID

Rono.  Sorting-out the engine set-up you've got on a dyno can make a lot of difference and save you a lot of frustration.  NOT inexpensive, I'm sure, BUT money well spent. in dialing it in AND not driving you crazy accomplishing it. 

I'm surprised at how much advance the engine likes, but I suspect that tuning a supercharged engine is a different game from anything I've ever worked on.

Best Wishes, Always,
Charlie


NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York

Charlie;
I've learned a lot over the past couple of days working with the shop owner on this. Today we got the A/F ratio mixture almost perfect by changing jets and the Idle and power valve restrictors. We set the timing back to 37 degrees all in and the boost control dial off the MSD box to 0. We basically tuned it for a street driver. I left the pulley's the way they were, at 10% under-driven and we got 7.5 lbs. boost at 5500 RPM. One issue I didn't consider was the cam which I never changed after giving up on the VS-57 unit. That cam was purchased for that blower and had 110 degrees lobe separation and 17 degrees overlap. For this blower the shop owner Frank said this cam should have 112 degrees lobe separation with only about 7 degrees overlap. I won't be changing the cam any time soon so it is what it is.

  Ron Lane,  Meridian, ID

any numbers Rono?

Daniel Jessup

Lancaster, California

aka "The Hot Rod Reverend"
check out the 1955 Ford Fairlane build at www.hotrodreverend.com

375 Ft. lbs of Torque at 4900 RPM. I'll just say the motor made between 3 and 400 HP, but didn't make any additional power over 4900 RPM and we think it was the cam profile that was the culprit. The Comp Cam that I had installed for the VS-57 supercharger had 17 degrees of overlap and 110 degree lobe centers. I believe the cam choice was based on the fact that you couldn't run the motor above 5500 RPM without over-spinning the supercharger and possibly burning up the ball drive. A more appropriate cam profile for the roots style blower may be a 114 degree lobe center and maybe 7 degree overlap. so that the boost wouldn't just blow out the exhaust. The motor did run well though so I am going to run it the way it is for a while.

  Ron Lane,  Meridian, ID

Talk to Ted about the cam he put into my 4-71 combination. It is super friendly on the street but makes horsepower too.



Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

Will do, Thanks!

  Ron Lane,  Meridian, ID

Hi, what cylinder heads did you use and what was done to them? also what is the deck height?

Thanks Cliff

Cliff; The heads were ported (by me) 471 heads. Not sure of the deck height.

  Ron Lane,  Meridian, ID

I run a 312 .060, with 471 heads, exhaust porting only, Isky RPM 300 cam and kit, stock manifolds (intake and exhaust), Holley 3310, spalding flamethrower, and a vs57 with a sn 2000 back half, it runs hard for what it is, I turn it about 6500, the engine comes on about 3500, I think you should be making at least 450 HP @ 6000, have you checked the cam timing? I have seen timing gears retard the cam as much as 2 1/2 deg.