Dyno'd the 352 again this morning....

[shady]

I suspect that it is just getting ready for St. Paddy's day. probably looking for a little alcohol.

[Twinibeam66]

Hey Brent sounds awesome ! Question what are the valve springs open and closed LBS ?

Thanks

[blykins]

280/680.

[Twinibeam66]

Thanks Brent pretty strong 

[turbohunter]

Sounds fantastic Brent.
Got enough carb?

[blykins]

I used the 830 Holley dyno carb.   That carb has been there for years because it makes more horsepower than anything else you bolt on.  It's a Scott Perkins special that is a bad chick. 

Bottom line is the plug got hot, hot enough to turn it green and glaze it over.   I just don't know *why* it got hot with nothing but a head flow change. 

The engine will pick up a good bit of power when I get back down there and throw some AR33s in. 

I've got a couple tricks up my sleeve if I need to sneak a few more hp out of it while I'm down there.

[427John]

This is weird,the easy answer is the higher flow heads leaned it out a little and demanded a colder plug, but the power numbers and A/F numbers don't support that. Did you try backing the timing a couple of degrees from the 42* to see if it made any difference?Was there any work done to the combustion chambers that may have increased the burn rate,kind of made it closer to a fast burn chamber?

[Stangman]

ith a better chamber and flow maybe it wants less timing like 427John said and maybe go up a jet size to try. That along with the colder plug who knows. I wanted to try going up 2 jet sizes to get into the 10s at the reunion. If I have my heads hand ported which Im thinking about Ime going 3 instead to start.

[Gregwill16]

Sounds great Brent! That would be a blast in a little Cobra.

[blykins]

Gonna head back down to the dyno this weekend and get it sorted out, then I'll be putting JJ up for sale, or parting him out if no one is interested.   Got my eyes set on another build.

[blykins]

Ok, we ended up with 465 hp @ 7200 this morning, turning the water pump.  410 lb-ft of torque. 

It still liked 42° timing and I just went ahead and put AR32 plugs in it.  Could probably have used the AR33's, but these worked.   38° total dropped 15 hp.  A 2" Super Sucker opposed to the 1" Super Sucker also dropped 15 hp.  Interesting. 

Little engine still sounds marvelous just sitting there idling.   Pulled hard to 7500. 

Debating on keeping it and trying other things.  It's earned a soft spot in my heart, we have beat on it hard. 

Video to come in a bit.

[frnkeore]

No other changes, just the AR32 plugs?

How low would it pull?

[blykins]

No other changes, just the AR32 plugs?

How low would it pull?

On a higher strung engine, pulling it hard at low rpm is not one of my goals.  Everyone knows that a 352 that's peaking at 7200 rpm is not going to have any guts down low, so there's no use in stressing the engine. 

A 4.30-4.56 gear would be this engine's friend.

[frnkeore]

The only reason I ask, is that you were talking about putting in a street car. Drag only, it wouldn't be a issue but, on the street, it would be nice to know what rpm you could use w/o it bucking.

So then, you only changed plugs and it picked up over 30 hp?

[blykins]

The only reason I ask, is that you were talking about putting in a street car. Drag only, it wouldn't be a issue but, on the street, it would be nice to know what rpm you could use w/o it bucking.

So then, you only changed plugs and it picked up over 30 hp?

I wouldn't run it down the street with it lugged under 2000 rpm, but it should do fine in a street car.  My definition of street is a little different than some others' LOL

Yes, the previous plugs were just too hot.   I was pretty confident that it would pick up with a spark plug change.  We basically gained 32 hp from the first iteration to the second iteration.   It also peaked the horsepower 400 rpm higher, which is a logical change going from a lower flowing head to a higher flowing head.  It makes it easier for the camshaft to do its job.