How much is the new combo gonna make?

SadbutTrue

SadbutTrue

Founding Member
May 1, 2002
2,390
4
49
Granada Hills, California
#1
Getting pretty excited, the new pushrods and the rest of the major components are coming in tomorrow from summit, and then just have to finish putting it together this weekend. Assuming everything goes well (fat chance...), could be running next week...

So, on that note, I can't wait any longer... how much do you think the below combo will make? I've always thought it'd be good for 400 hp and probably 400+ torque at the flywheel. Some have hinted that might be conservative, and then I see some results that make it seem like it might be unrealistic. Anyway...

351w .060 over
9.3:1 CR :(
Trick Flow Twisted Wedge Heads :rock:
Compcams XE274H camshaft (.519/.523 max lift, 274/280 adv duration, 230/236 @ .050, 110 LSA) :spot:
Weiand Stealth intake :banana:
Holley 670 Street Avenger :cheers:
Heddman 1 5/8" swap headers/2.5" exhaust w/ Hpipe/Flowmasters :neat:
MSD 6a/Pertronix Unit/Pertronix plug wires/Accel coil :shrug:

Goes through a T5 (that I hope doesn't break) and a 9" rear.

Been planning on a combo like this for a long time, think its pretty well matched, and every part seems at least on par with Edelbrock's Performer RPM package, which they advertise at 400 hp. I also realize this is small potatoes compared to what some of you guys are doing... but I'm still pretty amped. So... who knows?
 
#5
rhyno9 said:
Any chance you have the flow data for the heads? I have the compcams camquest software installed. I can input the cylinder head flow data and then maybe get a decent estimate.

I have already input the data for my cylinder heads (Windsor Jrs.) and using that cam it lists 350 hp and 400 tq.

RV
Click to expand...

Sure do! When i was on hold yesterday I did hear about that camquest software. Wasn't aware it had guesstimating capabilities ala desktop dyno on it... I might have to cehck that out.

Lift Value Intake Flow CFM Exhaust Flow CFM
0.100" 63 53
0.200" 141 107
0.300" 205 144
0.400" 233 171
0.500" 251 187
0.600" 251 193
 
#6
SadbutTrue said:
Trick Flow Twisted Wedge Heads
Click to expand...

I have the standard twisted wedge cylinder head flow data and that maybe will provide a decent estimate.

Camquest shows at a compression ratio of 9.3

397.7 hp
425.0 tq


I also changed the compression ratio up and the increase was minimal.

compression ratio of 9.5
401.5 hp
428.1 tq

compression ratio of 10.0
410.2 hp
435.8 tq

compression ratio of 10.5
416.3 hp
442.9 tq


RV
 
#7
SadbutTrue said:
Sure do! When i was on hold yesterday I did hear about that camquest software. Wasn't aware it had guesstimating capabilities ala desktop dyno on it... I might have to cehck that out.

Lift Value Intake Flow CFM Exhaust Flow CFM
0.100" 63 53
0.200" 141 107
0.300" 205 144
0.400" 233 171
0.500" 251 187
0.600" 251 193
Click to expand...

Using those flow numbers it says

410.5 hp @ 6000
428.9 ft/lbs @4000

Yeah it provides simulation numbers with all their different cams. You can obviously enter head flow data. The one gotcha is that the intake manifold selection is very weak. They give you 3 options

Dual Plane-std flow
Dual Plane-High flow
Dual Plane-Max flow

I choose the high flow which I believe to be a basic port match on a higher flowing intake. I just made the associations myself because they don't provide much insight on what the definitions are for each type. So my assumptions are as follows


Dual Plane-std flow=performer
Dual Plane-High flow="cleaned up" performer rpm/stealth
Dual Plane-Max flow="ported" air gap performer rpm/stealth

It used to be a free download, now it appears that they are charging $12 for it.

RV
 
#8
rhyno9 said:
Using those flow numbers it says

410.5 hp @ 6000
428.9 ft/lbs @4000

Yeah it provides simulation numbers with all their different cams. You can obviously enter head flow data. The one gotcha is that the intake manifold selection is very weak. They give you 3 options

Dual Plane-std flow
Dual Plane-High flow
Dual Plane-Max flow

I choose the high flow which I believe to be a basic port match on a higher flowing intake. I just made the associations myself because they don't provide much insight on what the definitions are for each type. So my assumptions are as follows


Dual Plane-std flow=performer
Dual Plane-High flow="cleaned up" performer rpm/stealth
Dual Plane-Max flow="ported" air gap performer rpm/stealth

It used to be a free download, now it appears that they are charging $12 for it.

RV
Click to expand...

Nice. High flow is probably a good guess. I had considered pocket porting the stealth to match the heads (since both are used I'm not sure there's a downside... and since it appears I will have plenty of free time this weekend maybe I will), but it probably isn't worth the time.

Im surprised there's that much of a difference over the Windsor Jrs. Thanks for checking that for me :cheers:

rhyno9 said:
I have the standard twisted wedge cylinder head flow data and that maybe will provide a decent estimate.

Camquest shows at a compression ratio of 9.3

397.7 hp
425.0 tq


I also changed the compression ratio up and the increase was minimal.

compression ratio of 9.5
401.5 hp
428.1 tq

compression ratio of 10.0
410.2 hp
435.8 tq

compression ratio of 10.5
416.3 hp
442.9 tq


RV
Click to expand...

That too makes me feel better. I had always heard that a 1 point (ie 9.0 to 10.0) jump in compression was worth abotu 10% (when you're talking about 8-11 CR ranges and non-ridiculous horsepower #s). Again, a bit surprised there isn't more difference.

Cooooool :flag:
 
#11
Dont worrry about the T5.Your combo wont probably make enough to break it on the dyno. I have the weakest of all T5’s and it lasted on the dyno and so far on the street. That’s not to say it wont break, because I know it will. But Im thinking about back to a C4.
 
#12
The T5 has the steel bearing retainer, and yeah, no slicks or 5k launches. Still figure it'll break sooner rather than later, but probably more on the 'in a year or two' timeline than 'within the first 500 miles'. I hope anyway.

I went with the 670 Street Avenger based on recommendations of many on this board who said that it'll work as well as most mech secondaried carbs and that my cam, while substantially more aggressive, is not so aggressive it will impact vacuum enough so as to hinder performance. I'll see how it goes.

My friend has a 650 double pumper with mech secondaries i might be able to buy and rebuild if I'm not happy with the 670 SA.
 
#13
Anyone have suggestions for good SoCal/Los Angeles-area dyno test/tune facilities? Particularly any deals on them? Seems some of these boards have the occasional free dyno days sometimes...

Also, still open for more guesses. Like I said, closest gets a 6 pack :)
 
#16
woodsnake said:
I have the same cam/carb combo on my 69 Cougar, plus I have the air gap intake.

I hate to be a buzz kill, but at the rear tires, no more than 225 hp.
Click to expand...


What heads are you using though? That cam/carb/intake combo with stock heads or GT40s is gonna be a lot different than what it makes with quality aftermarket parts. But thats cool, got you down for 225 rwhp.
 
#19
squidz said:
You remember my dyno from last week. I only got 305hp and 320 tq to the wheels and my setup is basically the same as yours...

347 stroker
Click to expand...

Well, I wouldn't be incredibly disappointed with those #'s. Disappointed, sure, but that still translates to 360 hp/380 tq. Can't complain too much there.

And like I said in that post, I do believe the Trick Flows will outperform the Patriots. Same exact carb, similar camshaft, and similar intake. Forget what you had for exhaust, but I do have longtubes and 2.5" pipes/h-pipe all the way back, so probably similar there too.

You have an extra point of compression on me, not sure how much of a difference that makes (as I said earlier in this thread, I had always heard 10%, but then again those simulations above imply that it might only be worth 5-10 hp). I also have 15 extra cubes (351w .060 over = 362.5 cid) which probably compensates for the compression edge you had.

What does that all mean? :shrug: Basically, i think they're basically identical setups except the heads, which are the most important part. I guess you'll see how good/bad those Patriots really are when I finally do get a dyno done.

Like I said though, I wouldn't kill myself over 360 hp. Considering I was probably running with 225 (if i'm lucky) before... it'll still feel pretty good, heh.

If I get it together tonight or tomorrow night, I might try to break it in Friday and dyno it this weekend or next.
 
#20
you should make around 400 hp/ TQ at the flywheel maybe a touch more, TW heads are great on 351w engines the flow #'s are not super high but low lift and mid lift flow are some of the best of any head made and because of the int valve being closer to the int port the smaller port size works excellent.

My 351w made 360 fwhp with 8.9 compression, TW heads, hyd roller with 212 220 520 542 with a torker 2 and a demon 650 VS carb.
 
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