Thoughts on 372" sb requested.

Posted By: Cevidicus

Thoughts on 372" sb requested. - 01/14/15 09:55 AM

A friend has this 372" small block that's built and ready to go. I just want to get some thoughts on its power potential and what could be expected from it in say a 3400lbs a body. All thoughts and criticisms welcome. I just want to know what y'all think its capable of. Thanks!

372"
340 block .030 over,
360 cast crank with mains turned down to fit,
eagle rods,
KB hyperutectic pistons,12.5:1,
W2 heads ported and flowed 290,
Mopar 1.5 roller rockers,
Howards solid .599/.620 solid cam,
Holley strip Dom intake

Posted By: MR_P_BODY

Re: Thoughts on 372" sb requested. - 01/14/15 03:04 PM

Quote:

A friend has this 372" small block that's built and ready to go. I just want to get some thoughts on its power potential and what could be expected from it in say a 3400lbs a body. All thoughts and criticisms welcome. I just want to know what y'all think its capable of. Thanks!

372"
340 block .030 over,
360 cast crank with mains turned down to fit,
eagle rods,
KB hyperutectic pistons,12.5:1,
W2 heads ported and flowed 290,
Mopar 1.5 roller rockers,
Howards solid .599/.620 solid cam,
Holley strip Dom intake

That would be about 520hp... JMO

Posted By: 1967dartgt

Re: Thoughts on 372" sb requested. - 01/14/15 03:36 PM

Haven't seen good luck with 360 cranks in 340s. Should be a stout motor, high tens if you max the combo.

Posted By: J_BODY

Re: Thoughts on 372" sb requested. - 01/14/15 03:41 PM

Cast crank with mains turned down makes me cringe...... but I'll wait for more knowledgeable folks to kick in.

Posted By: Guitar Jones

Re: Thoughts on 372" sb requested. - 01/14/15 03:44 PM

Quote:

Haven't seen good luck with 360 cranks in 340s. Should be a stout motor, high tens if you max the combo.

I agree on the 10's. I don't know about the crank but I'd think if you kept the RPM's under 7000 it would probably hold up.

Posted By: MR_P_BODY

Re: Thoughts on 372" sb requested. - 01/14/15 03:51 PM

Quote:

Cast crank with mains turned down makes me cringe...... but I'll wait for more knowledgeable folks to kick in.

In 73 the 340 had a cast crank... it was just the 1
year then the 340 died

Posted By: 70AARcuda

Re: Thoughts on 372" sb requested. - 01/14/15 04:11 PM

MP/Scat sells a 3.58 stroke 340 main cast crank.

Should be in the 10s...

Posted By: Rob C

Re: Thoughts on 372" sb requested. - 01/14/15 04:32 PM

That is an old time poor mans stroker combo that has been very effective.
The turned down cast crank should not be a problem if it was proper done and treated correctly. I remember reading a long while back a fella did that combo and topped it with ported Edelbrock heads and a roller. It dyno'd high 500's. A very stout combo.

Posted By: Thumperdart

Re: Thoughts on 372" sb requested. - 01/14/15 05:11 PM

What carb..............

Posted By: cudadoug

Re: Thoughts on 372" sb requested. - 01/14/15 07:35 PM

Ditch the Eagle rods, unless they're H beams. If you want I beams, RUN AWAY. SCAT for I beams.

Posted By: cudadoug

Re: Thoughts on 372" sb requested. - 01/14/15 07:39 PM

Quote:

MP/Scat sells a 3.58 stroke 340 main cast crank.

Should be in the 10s...

A buddy of mine was going to do this SAME combo. "Poor Man's Stroker"? Well, not so much. GOOD shops were quoting him $500 and up to cut and re heat treat the crank. Bought that MP/SCAT from Jegs for $360-ish.

Posted By: 340B5

Re: Thoughts on 372" sb requested. - 01/14/15 07:49 PM

Get a good crank and use a lot of converter. 10.90's maxed out w/4.86 gear.

Posted By: 733404spdCuda

Re: Thoughts on 372" sb requested. - 01/15/15 12:13 AM

My Combo built by MRL Racing

340 Block 4.100"
3.58 Eagle Crank
2.100 Eagle sbc H Beam rods
Diamond Piston 9.7 comp
Edelbrock 63CC Heads CNC ported my MCH
Houghs 1.6 roller rockers
Solid 243/251 duration @ .050" .550/.570 lift
Edelbrock RPM Intake
Kevco pan with baffles
750 quickfuel carb

520HP @ 6200 and 490TQ @4500 on pump gas

Nice street / strip motor

Attached File

8396392-JimB3780001(3)(1).pdf (132 downloads)

Posted By: Cevidicus

Re: Thoughts on 372" sb requested. - 01/15/15 04:34 AM

Thanks! What y'all are saying is right about what I was thinking.

Posted By: cudadoug

Re: Thoughts on 372" sb requested. - 01/15/15 07:23 PM

Sorry OP, I didn't realize that you said "BULIT" (as in ALREADY BUILT)in your opening post before I started running off at the mouth.

Posted By: CMcAllister

Re: Thoughts on 372" sb requested. - 01/15/15 09:14 PM

2250# door car. 9.40s, 30s on a good day. 142-143 MPH. 7200-7400 RPM. 360 crank cut with no other work other than balanced.

I fought rod bearing issues for a long time before doing some work on the oil system. Still had to do bearings at 120 runs, but that's about what I put on it in a year. Just freshen it up over the winter and put it back in.

That was a while ago. Wouldn't do it again with the parts that are available now unless it would maybe be a nice street deal with less RPM. Inexpensive cubic inches.

Posted By: topside

Re: Thoughts on 372" sb requested. - 01/16/15 04:35 AM

Basing my comments on my 368" Batten W2 motor Duster:
There's 300-320 CFM in a W2 head. But the flow "curve" matters.
Good intake, same here. I'd prefer a lighter piston with a low-drag ring pack. Hopefully H-beam rods.
Cam sounds a bit small on In and quite offset on Ex...what's the lift specs?
It'll want at least an 850CFM carb.
Depending on tire, 4.88-5.38 gear & proper converter (probably 5500 or so) a W2/372 should go mid/high 10s @ sea level in a 3000-3200-lb A-body.