HP/torque Calc to help determine new transmission

[oceanhighz]

So, my transmission needs to be replaced and I'm trying to figure out which 200r4 to put in it (if I choose to stay with one instead of replace with a th400). Between a few different shops, they have similar transmissions but I need to figure out torque numbers (most important) and horsepower.

So here it is:


The engine is a 400 two bolt main SBC from a 1972 caprice, no emissions equipment at all. It's bored .020 over which makes it about a 404. Here is what I have:


RHS Racing Aluminum Heads 180cc Runner, 72cc chambers 2.02
intake 1.6 exhaust

Holley Street Avenger 670 cfm
Federal Mogul Hypereutectic Flattop Pistons
Sealed Power Moly Rings
Clevite Rod Bearings
Clevite Main Bearings
Clevite Camshaft Bearings
Melling Hi-Volume Oil Pump (street pump)
PBM Performance Camshaft .465" intake .465" exhaust 220 duration
Speed Pro Lifters
Cloyes TRUE Roller Timing Set
Freeze Plugs
FelPro Gasket Set 1205 (.060 thickness)
1.6:1 Aluminaized Full Roller Rocker Arms w/ Lock Nuts
Trick Flow Hardened Push Rods and Push Rod Guide Plates
Hardened valve Springs.



So for the compression calculator, I used http://www.angelfire.com/fl/procrastination/motor.html

Bore: 4.125
Stroke: 3.75
Cylinders: 8
Chamber in cc's: 72
Flattop pistons (confused about this part, I would think since the pistons say +6CC (they have valve reliefs) that you would subtract that space in the calculator)
Compression I came up with was about 10.1:1, although this may be off depending on if the calculator is accurate, for some reason I thought when I calculated before I was closer to 10.5 or 10.8:1.

I have electric cutouts in my headers (3inch openings), and if they are closed, it goes through true dual exhaust that is 2.5inch and the mufflers are flowmaster hush power II's.

I realize based on tune, carb jetting, and vacuum advance the HP and torque could change, but I'm looking to a general baseline so I can figure out what I need. I'm thinking I'm somewhere around 400ish right now, and may go up some if a better tune was put in (will be done after new transmission, which is part of the reason I'm concerned with picking the right one.

Any help would be greatly appreciated, as I cannot find an accurate torque calculator and I never had it dyno-ed before the transmission went up.

 

[SSedan64]

You didn't include your Deck Height or Head Gasket thickness above.
Assuming:
4.145" Bore X 3.75 Stroke.
4VR Piston 6cc, 72cc Chamber Head.
0 Deck Ht., .040" Gasket / .040" Quench.
Would = 10.55Cr.

Comp has a free Dyno download called CamQuest 6. >> http://www.camquest.com/

 

[oceanhighz]

SS: thanks for the input, I appreciate it. The gasket thickness is in there, next to the gasket set I have in there. 0.60 thickness.

Deck height, I'd really have to go through my paperwork, I don't remember off the top of my head. I'll look into it. I've downloaded that program before and couldn't get it to work, I'll try it again.

PS are you retro on MCSS?

 

[SSedan64]

Yes same as on MCSS.
I saw the .060" by the 1205 Intake Gasket & it confused me. With everything else the same but using the .060" Head gasket Cr= 10.09
A thinner gasket would be much better. If your Deck Height is stock at about .025", a .015" coated Steel Shim gasket would work and give .040" Quench.

Just a guess but, CK's & EA's Level 1 or TBP's Basic or Standard 2004R builds should be fine.

 

[oceanhighz]

I asked my Dad about Deck height as I wasn't sure I remembered correctly, and he said it was about .020. We used a thicker gasket, because we were trying to keep the compression down and the calculator we were using was still reading it out at about 10.8:1. When I go to replace the head gaskets again, I'll remember what you said and replace them with thinner gaskets. We were trying to keep the compression based on that calculator within the range of premium pump gas. I'll definitely keep that in mind. I'm going to look around a little more locally, and if I don't find anything within a day or two, I think I'm gonna order the EA Stage I. I thought about turbo-ing my car eventually, but not so sure that'd be anytime soon, so I'll just stick with what I have and get a transmission to match.

 

[SSedan64]

With .020" Deck Ht. & .060" Head Gasket your Quench will be .080", not good. This can make the engine prone to Pinging/Detonation. Compression would be about 9.67Cr.
Running .040"-.050" Deck Ht. would make the Engine more resistant to Ping, Compression would be about 10.30-10.40Cr. Also with Aluminum Heads you can normally run about 1 point more Cr. than with Cast Iron Heads.

Could run a slightly larger Cam in the 405, the extra cubes will tame down a Cam's duration compared to running in a 350 engine. Most all SBC cam rpm operating ranges are for 350ci.
Basic Duration vs Compression guide:
http://www.chevytech.info/2c40o5.html

Is this your Cam? Erson E110038K
http://www.pbmperformance.com/store.php?catId=327

 

[oceanhighz]

yea, thats the cam. I thought about replacing the cam when I had to redo the top end (guy before me was a hack, and was running the timing too far advanced and it cracked the head shortly after I got it). Money was tight, so the cam stayed. As of right now, the engine isn't having a problem with detonation or pinging, and I'll keep it in mind when I take the heads off to replace the gaskets. My dad has built many cars and was a mechanic for a long time. He'd heard things in the engine I never noticed until he pointed out what they were. I'll make sure to pay attention and ask him to after I get the transmission replaced. Right now, everything else is gonna stay as is, because the transmission is all I can afford at the moment. I've basically replaced everything the guy I bought it from didn't do a good job on, so hopefully from here its all easy sailing
new transmission will be next, bottom end is good, top end is recently rebuilt......