360 dyno

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Dalton697

Dalton697

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Trying to figure out why this came in so low

Motor is rebuild 360
.60 over
9.3:1 piston
Xe268 comp cam
Wieand dual plane intake
Edelbock thunder 650 with 100 primary and 102 secondary
 

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1. Chassis or Engine Dyno?
2. Was the Cam degreed?
3. Was the timing & air/fuel adjusted on the dyno or is this just a one pull deal?
 
This was whp

Cam is
Lift 477/480
Duration 268/280
Cam installed @106

This was just 3 pulls with no adjustments
 
Without A/F ratios it's hard to say, BUT, I'll guess it's fat.

Should be making 320-340 the crank on a dyno. Figure about 250-270 at wheels.
 
I'd probably do a leak down check to rule out an internal issue. Also, how's the exhaust setup?
 
Comes stock with .095 and .098 jetting and you've got .100 and .102... That's a big jump with the stock metering rod.

Dynos are fun, should have had a sniffer in it to give you some A/F number so it would have been useful to further tune it up.
 
This is stock exhaust manifolds into 2 1/4 with h system, and we bump the jet to get max performance out of the 650 without going to 750 and 110/113
 
I know I need headers, but need to find good header for a 74 sport 360 that don't break the bank and work with power steering and power brakes
 
That looks like the results I got on my 'Cuda

My build:
Low compression build 8.5:1 87 octane
.060 over dished pistons in the hole
Comp XE284 Hyd. Cam
Eddy Alum. RPM heads
Eddy Air Gap intake
Eddy 500 cfm carb
Stock cast iron big bore manifolds
TTI 2-1/2 exhaust with h pipe
2800-3200 converter
Roller rockers

My air/fuel was right in the middle
Only had them run mine up to 5000 rpm

Those numbers may be typical for a low compression build
with "big" cams.
 

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Dalton697 said:
This is stock exhaust manifolds into 2 1/4 with h system, and we bump the jet to get max performance out of the 650 without going to 750 and 110/113
Click to expand...

That doesn't help if the carbs original calibration was spot on. The 750 has a larger jet because it can pass more air.

Putting larger jets may not help performance and could cause it to go backwards. The increase you have may be as much as 18% in fuel delivery that is unneeded.
 
crackedback said:
Without A/F ratios it's hard to say, BUT, I'll guess it's fat.

Should be making 320-340 the crank on a dyno. Figure about 250-270 at wheels.
Click to expand...

crackedback said:
Comes stock with .095 and .098 jetting and you've got .100 and .102... That's a big jump with the stock metering rod.

Dynos are fun, should have had a sniffer in it to give you some A/F number so it would have been useful to further tune it up.
Click to expand...

crackedback is again absolutely correct. Those carburetors come jetted for sea level. Even though you are only at 400' elevation it probably could have been jetted down a small bit. As it is you have richened the carburetor 11.6% by increasing the total jet area from .0258 sq in to .0288 sq in.
 
Dalton697 said:
This was whp

Cam is
Lift 477/480
Duration 268/280
Cam installed @106

This was just 3 pulls with no adjustments
Click to expand...

Sounds right to me for RWHP. YOu have a small cam, small eddy carb and low compression. So you have a mid 300hp combo at the crank. I think you made out well.
 
roccodart440 said:
Sounds right to me for RWHP. YOu have a small cam, small eddy carb and low compression. So you have a mid 300hp combo at the crank. I think you made out well.
Click to expand...

I think 300hp for this engine is highly optimistic. Mid-300? very unlikely IMO.
 
frosty_the_punk said:
I think 300hp for this engine is highly optimistic. Mid-300? very unlikely IMO.
Click to expand...

It's a shame to have to agree. But even considering this could be a very stingy dyno, it looks like no more than 266 hp at the flywheel.

I'm thinking there would be some more with a proper tune.
 
How does it drive? Does it feel like it has more than 200hp?
 
IQ52 said:
It's a shame to have to agree. But even considering this could be a very stingy dyno, it looks like no more than 266 hp at the flywheel.

I'm thinking there would be some more with a proper tune.
Click to expand...

Yes, I thought it had headers for the range I original gave.

It's probably a 300-310 engine and missing some on the tune up to have the current results..
 
"This was just 3 pulls with no adjustments"

Without knowing the timing setups, and the fuel curve you're just guessing anyway. We used to do those "3 pulls for $100" deals and at least 60% of the time guys were disappointed because they only think about the numbers. Several either sold the car or pulled the engine as a result. With some real tuning I'm sure that could be picked up. But unless you have a really savvy guy to tune it off the dyno, or cash to tune it on one (and again - with the right guy), then those results are nothing to worry about.
 
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