Dyno results

[awsumcars]

I trust all had a great Christmas and looking forward to seeing all @ Beech Bend in June hint hint . Santa didn't check over his list very well cuz the race engine was pulled off the dyno just in time for Chrismas! ....I attached the dyno sheets here and had some questions. It seems the torque peaks and flattens out around 5100 rpm and the HP peaks and starts to fall off @ around 6000 rpm. I thought it would pull a little better through that range. Most of the specs are noted on the dyno sheet except it doesn't mention that I have the stock dual quad intake with Hooker headers. My guess is that the intake may be holding it back but I have no experience with this so I was looking for a little input. The car has a 2 speed powerglide, so I was wondering were the shift point would be best.

 

[Don Jacks]

Yes,I'd say there's a problem[by about 25-30 hp] with that intake.As the package stands now,shift it at 6,300.40 degrees of timing may be a bit much as well.

 

[La Hot Rods]

How much help are the carb spacers for this intake?

 

[BSL409]

How much help are the carb spacers for this intake?

I know when we did my first stoker with the stock 881 intake we picked up almost 15HP with the 1" open spacers

 

[models916]

Should have dyno'd with 36-38 to see what happens. Those big Hookers will maybe like less timing.

 

[63 dream'n]

congratulations on your build........

 

[La Hot Rods]

In the first dyno sheet it goes flat from 5700 to 5900 rpm.
Maybe the dist needs recurve.
What was changed from the two pulls?

 

[awsumcars]

I have 1/2" open spacers, mainly to clear the hood with stock air cleaner. The engine builder played with the jetting and timing the day before these pulls (I wasn't there). I mentioned to him that these engines usually run @ 36 and he said it liked 40.
(I didn't get those pull sheets yet). They also pulled the springs out of the distributor and locked it??? Nothing was changed at all on the last pulls. There was actually 1 more pull, which was pretty much identical to the first pull. It's a pretty reparable engine builder in Denver, but being a "small guy", and not spending 40K+ on an engine, I don't feel like I got very good attention, and being a rookie, don't really know how to address things correctly, trusting them to do the right thing. The dist recurve thought makes for interesting question for them. I appreciate all comments.

 

[Don Jacks]

When you get it in the car,and the car on the track,you may have to adjust both the timing and the jetting.I'd suggest running it just as it came off the dyno for a few runs to establish a baseline,then back the timing off and watch for mph changes.A lot will depend on the operating temp.If you run between 140-165 degrees or so,it might not want as much as it has now.

 

[awsumcars]

When you get it in the car,and the car on the track,you may have to adjust both the timing and the jetting.I'd suggest running it just as it came off the dyno for a few runs to establish a baseline,then back the timing off and watch for mph changes.A lot will depend on the operating temp.If you run between 140-165 degrees or so,it might not want as much as it has now.

That makes sense Don. I'm not looking to squeeze every ounce out of the engine, just want to learn a little and enjoy the sport, camaraderie and share the stories with this great group of gear heads.

 

[snoopybob]

I think it's good that it has a "flat" HP. peak. Wish mine looked like that. However; the "problem" is more like 150 HP.

 

[awsumcars]

I'm not sure I understand what's good about the "flat" HP peak?

 

[snoopybob]

That's just more available horsepower for a longer period of time.

 

[snoopybob]

I think you need a bigger cam

 

[buildit]

I think using the stock #881 manifold will nullify some of the advantage provided by the BWR heads? What is the comp. ratio?

 

[snoopybob]

The cam: I think you need about a 268-278 ( @ .050 ) ground with 112* lobe separation and degreed in at 108 ( 4* advanced)

 

[awsumcars]

I think using the stock #881 manifold will nullify some of the advantage provided by the BWR heads? What is the comp. ratio?

I'd agree with that....Then the next question is what intake ....probably McQuillen (to fit under the hood), otherwise, I think Walden's would be the way to go. Dreamin' here of couse . I'll stick with this for now, but really would like to try Aubrey's Speed-port 7000. With the right carb setup, I think it would out perform the stock 2-4's, but loose the look.

Oh yes, the compression came in @ 12.2..........

 

[snoopybob]

By the way--I have a cherry set of original carbs and intake like yours for sale. Also 340 hp. BIG Rochester 4GC and manifold. Thanks. Also : If you don't have an 8" converter, you need one BAD.