critique my 340 w2 combo please

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bigfoot

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Here is what I have to peice together a combo for a 72 dart. It will be a mostly street car running a viper t56 6 speed with a .50 od sixth gear.

Short block is a rebuilt forged crank 70 style trw flat tops .036 above the deck (verified).

Heads are 810E w2's. 2.05 intake 1.60 exhaust. Chambers are 66cc open chambers. Lost the flow sheet on the heads but remember the flow 198 at .300, 260 at 500 and 270 at .600 lift.

Cam is a racer brown hydraulic roller, 236 at .50 on the intake and 241 at .50 on the exhaust. .545 lift 108 lsa and installed at 106.

Intake is an M1 single plane, copy of the holley street dominator, plenum ported. It will be setup to run port efi.

My question is how will this run on the street? Will it be a slug until 5k? What should it make for horsepower, compression looks like pump fuel may be questionable.
 
bigfoot said:
Here is what I have to peice together a combo for a 72 dart. It will be a mostly street car running a viper t56 6 speed with a .50 od sixth gear.

Short block is a rebuilt forged crank 70 style trw flat tops .036 above the deck (verified).

Heads are 810E w2's. 2.05 intake 1.60 exhaust. Chambers are 66cc open chambers. Lost the flow sheet on the heads but remember the flow 198 at .300, 260 at 500 and 270 at .600 lift.

Cam is a racer brown hydraulic roller, 236 at .50 on the intake and 241 at .50 on the exhaust. .545 lift 108 lsa and installed at 106.

Intake is an M1 single plane, copy of the holley street dominator, plenum ported. It will be setup to run port efi.

My question is how will this run on the street? Will it be a slug until 5k? What should it make for horsepower, compression looks like pump fuel may be questionable.
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With Jim doing the cam and 5 gears how could it be a pig down low?
 
yellow rose said:
With Jim doing the cam and 5 gears how could it be a pig down low?
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I bought the cam used. This is kind of a throw parts I have laying around on a budget combo, so Im wondering how it will run. Also my first engine build.

The machinist I had do the block and flow the heads is a chevy race engine builder in the area, has never seen w2 heads and was worried about the port size. He compared it to a boss 302...
 
3000 rpm and up will be a blast.
Below that 'might' feel soft, doubtful .. but will recover quick. The trans and if you have 4.10+ gear ,then compression you have ...it should compensate a good amount for the short stroke down low.
 
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100% high overdrive, LOL! That might require the torque of a black hole to pull unless you are running 5.57 or lower gears. But otherwise, I see it being pretty responsive if geared properly in the first five.
 
AJ/FormS said:
Why the 6speed for street? Cuz you already have it?
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I have it, and I live in montana. We have lots if wide open highways and 80mph speed limit/suggestions here! I was thinking a 4.10 or 4.30 rear gear might be ok starting around 80 in 6th gear.
 
Depends entirely on what rear tires you are planning on running. 4.10s will be 2.05:1, 4.30s will be 2.15:1, 4.56s would be 2.28:1, and 4.88s would be 2.44 in 6th. Drive line balance and fabrication becomes really critical when you start running it twice the rpm of the engine. Whole different world out there on the Montanabahn, though.
 
Oldmanmopar said:
Toss the hydraulic and install a solid. You'll be happier
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^^^^^^^THIS^^^^^^^^^

If Jim at Racer Brown didn't pick that cam I'd sell it.

IMO, you need a relatively fast lobe for that head on your displacement. The very LAST thing you need is a slow lobe that opens early, and slow, and closes late and slow. That will be a power killer

Cams are relatively cheap. Get the right one and do it right.

Also, your head guy is hilarious. The Boss 302 intake port is a very slow, lazy port. The W2 is nothing like that.
 
yellow rose said:
^^^^^^^THIS^^^^^^^^^

If Jim at Racer Brown didn't pick that cam I'd sell it.

IMO, you need a relatively fast lobe for that head on your displacement. The very LAST thing you need is a slow lobe that opens early, and slow, and closes late and slow. That will be a power killer

Cams are relatively cheap. Get the right one and do it right.

Also, your head guy is hilarious. The Boss 302 intake port is a very slow, lazy port. The W2 is nothing like that.
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What should this combo make for horsepower?
 
Are you going to use the cam specified and what is your actual static compression ratio going to be? Do you know the exact timing events of your cam?
 
Garrett Ellison said:
Are you going to use the cam specified and what is your actual static compression ratio going to be? Do you know the exact timing events of your cam?
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Im probably going to be using the cam specified. Static compression comes out at 10.25 to 1. I dont have the cam timing events handy, but remember its installed at 106. I think dynamic compression came out around 8.5 to 1, 180-185 psi.
 
you own that cam run it
too many variables to make changes till you get your build dialed in
post up your cranking compression and a dino sheet if you dino it
have fun
take notes
 
I would expect an "average" of about 1.3 hp per cubic inch, give or take a couple of tenths. That 108 LSA with that monstrous plenum probably won't play very nicely together at lower rpm, even with direct port injection. The mid to upper rpm should be incredible, though.
 
Pump gas should not be a problem with this build. Unless you can not get at least 91 octane.
As far as power goes, I’m not sure if I’m with YR on 500hp but I’d agree real with close to it.
 
Be prepared to run a quality, fresh, 91 octane if that's the best you have available to you...and maybe some octane boost handy if its questionable.
I've run 188 psi on 91 w "tight quench" and it was not making more power over 25-28 degrees full advance/total..so start it/break it in at no more than 30* total timing till you figure it out. That's my advice.
I've decided 185 is the max I care to run on 91 anymore. ..it just keeps getting worse in California.
Oh and if you dont believe me, try like I said...then get some 100 sunoco and run it, tune unchanged...and you'll feel what I'm saying. It just gets by, but it's a few short of what it could put out... still better than less compression/less power
 
mbaird said:
What part are you in ? Thats about as low as itgets for MT
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Currently in Fort Peck area, moving to the bigfork area. Both are about 2500 give or take.
 
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