462 Stroker - Disappointed

[Nightmist66]

Howie, in the vid., did you have the Jerico in yet and also was it the 3.25 gear in the description?

I have a wheezed out little 390 with a mild hyd. flat tappet in mine and even with the drag radials and Cal Tracs, I have no problem putting some rubber down.

It was a pretty stock 390 with iron heads, Wide Ratio Top Loader and believe it or not a 3.25 highway gear.
The Jerico with much steeper rear gear will get a smidge of air.

Seemed decent. Which cam did you run then?  I remember the pic you posted of the air at the track. 

Mine still has original heads with a home port, for now.

Sorry for getting off track on this post, rockhouse. Btw, it should run a tad richer with the air cleaner in place.(slight restriction in air flow)

[cjshaker]

The AFR ran in the 14's from 2500-4000 RPM and then in the 15's after that.

That actually kind of scares me. You said you had the timing all in by 2000, which is a FAST curve. Couple that with a pretty lean mixture, which you've got, and you've got a detonation scenario. That will kill power in a MAJOR way, along with bearings, rings and pistons. It's not always easy to hear detonation with a big block engine either. Granted, you have a stock exhaust, but it can still be faint to hear sometimes.

[4twennyAint]

I didn't see any mention of fuel volume.  A kink in the fuel line under the car somewhere, or a restriction in the tank can goof the deal all together. 

[plovett]

I also think something is wrong.  Not just the high overall gearing.  A bone stock 428 CJ Mustang would run about 14 flat at over a 100 mph with a close ratio toploader and 3.50 gears.  I'm sure the launch required some deft clutch work, but still it would no doubt fry the tires.

My first thought was timing.  The curve does sound too fast to me, but that shouldn't kill the low end.  Doug had a good point about detonation with the quick curve.  That could be exacerbated by the high overall gearing.   The total timing sounds low to me for factory heads, though rockhouse66 says it was set on the dyno, and he's experimented with it.  I would have expected 39-40 degrees total timing to make the best power.

I think you should concentrate on ANY differences in the engine between the dyno and the installation in the car.  Fuel supply was mentioned.  Exhaust was mentioned.   Are you sure the timing is still right?  Balancer slipped?  Different coil in the car than was used on the dyno?

JMO,

paulie

[rockhouse66]

The total timing sounds low to me for factory heads, though rockhouse66 says it was set on the dyno, and he's experimented with it.  I would have expected 39-40 degrees total timing to make the best power.

I think you should concentrate on ANY differences in the engine between the dyno and the installation in the car.  Fuel supply was mentioned.  Exhaust was mentioned.   Are you sure the timing is still right?  Balancer slipped?  Different coil in the car than was used on the dyno?

paulie

Good points and I agree.  This is the 4th iron head FE I have run on this same dyno and the best power always points to timing in the mid 30s which is a little puzzling since so many run high 30s and even 40.  I'm not worried about the fuel supply because it pulls quite well in 4th which should eat fuel.  And as noted, I had my thinking cap on backwards and the air cleaner should richen the mixture but it could still be pretty lean so I will jet up a bit and see what happens.

Thanks for the input and concern guys.  I don't know if I will get a chance to test more this year as Winter is on the doorstep here.

[machoneman]

Thanks for the input and concern guys.  I don't know if I will get a chance to test more this year as Winter is on the doorstep here.

By all means do your testing now. It'll give you some peace of mind, knowing come Spring it's all good to go. Have had the same dilemma here on other issues and always kicked myself after parking my cars and wondering still what was wrong come Spring.

[Falcon67]

I would be looking for 12s in that range, 13s maybe at cruise.  That's way lean IMHO.  That may also contribute to the soft leave, along with not enough - or properly calibrated - pump shot.  As above, 3.70s min or 4.11s in the back to work with that motor.