Thread: 1937 Plymouth 5 Window Coupe

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Originally Posted by mprevo

I also have not purchased the gars for the rear end yet so I still have that option open to me yet also.

I'd go for a TH400 1:1 transmission and some 5.13:1 cogs. That's what the cam will want.

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OK, your stack is 9.015". Now you need to know the block deck height so you can determine the head gasket to use in order to put your squish/quench at 0.030" to 0.032". If you can't find a readily available gasket, you'll need to cut the decks to +0.004" and use this gasket.....
http://www.summitracing.com/parts/na...make/chevrolet
Or cut them to -0.009" and use the Fel-Pro 1003. This is based on a static compression ratio of 10.5:1 to 12.0:1, which is what the cam will want.
With the piston at 0.004" down in the bore with the piston at top dead center and using the gasket shown above, your static compression ratio would be 10.68:1 and the squish/quench would be 0.032".

The cam you have chosen will want to cruise at somewhere between 3800 and 4600 rpm's. Sort of makes your 700R4 choice look a little silly, doesn't it?????

That cam will also want somewhere between 10.5:1 and 12.0:1 static compression ratio to work right. Good luck trying to run the motor on pump gas. The aluminum heads will help make it work, but you'll need a really tight squish/quench. I'd be engineering it down around 0.030" to 0.032" as I suggested above.

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A couple more thoughts as I read through your list of parts....
I would not use the Air Gap model of the Performer RPM, I'd use just the plain old RPM due to drivability problems in cooler weather with the Air Gap. I also would not use 1.6 rockers due to the additional strain on the entire valvetrain. You will gain from nothing to maybe 10-12 horsepower with them, not worth the strain put on the system in my opinion.

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Certainly no expert, but curious why you choose a 6-3/4" balancer over a 8" for your cast stroker crank? And, why forged pistons over hyper? Won't the additional piston clearance and expansion rates affect the streetability? Again, I'm no expert and don't mean any disrespect, just trying to learn.

Originally Posted by 36 sedan

Certainly no expert, but curious why you choose a 6-3/4" balancer over a 8" for your cast stroker crank? And, why forged pistons over hyper? Won't the additional piston clearance and expansion rates affect the streetability? Again, I'm no expert and don't mean any disrespect, just trying to learn.

I would believe your curiosity to be well-founded, as it has appeared to me over the years that the OEM's use a larger and larger damper the longer the stroke gets. This larger damper, however, tends to require additional torque to accelerate, torque that could be applied to the rear tires to accelerate the vehicle. So most fellows who want to accelerate the vehicle quickly will choose a smaller damper at the expense of betting that the subsequent lack of damping won't crack the crank. Here is probably the best collection of technical information that I have seen gathered on the subject of harmonics......
Damper White Paper : BHJ Dynamics, Harmonic Dampers and Specialty Crankshaft Vibration Dampers

As far as pistons, most fellows will find that a street motor will do just fine with cast pistons or cast hypereutectic pistons. The hyper part simply means that there is an overage of silicon used in the alloy that the pistons are made from. As you have alluded, the cost and initial start-up noise from excessive piston to wall clearance makes forged pistons seem like overkill for the common street motor. Now, if a fellow is going to add spray or bolt on a lung, then forged pistons begin to look like a better choice.

I don't know if we'll ever see mprevo back posting here again because I may have embarrassed him by telling him the truth.
Here is his post telling us who recommended the overdrive transmission and the fellow's credentials.....

"I have already purchased most of the parts for the engine. The cam I selected is a little aggressive but my tranny builder says it will be OK. My friend (and builder) owns a transmission shop and is probably the best mechanic & builder I know. In fact he also teaches these subjects at our local college. He is going to go through this 700R4 from top to bottom with me. He is the one that told me this is the tranny I need for the usage I am planning. He says he can build it "bullet proof" for me. Only time will tell though. Why do you say it won't work? I always say that I'm never to old something new from the experts, so I would be interested in your thoughts."

Well, I told him that this transmission fellow failed to take into consideration the camshaft that was to be used in this combination and matching the cruise rpm to the final drive gear ratio and so I suspect that mprevo is a little put-out over that as well as a few other comments I made concerning his choices.

It is my hope that he will continue to post here, but I have my doubts.

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Mprevo, I hope that you understand that everything said here is offered in a spirit of helping people understand how to get to the end package that fits their needs, as opposed to simply throwing money at suppliers for the biggest, best, baddest pieces and parts and maybe being disappointed when they've built a racer that doesn't street well.

My roadster project is a 700R4, and I went in and tweaked my spreadsheet for 4.11 gears. If you manage to fit a 30" tall tire at 70mph you'll be spinning 2256rpm; or 2333rpm with 29" tires; or 2417rpm with 28" tall tires. If your engine has a torque curve that comes in at 3500rpm and up your going to be so far down on the curve your economy is going to really suck, as will the driveability. It's not that it won't work, but if you're looking for a cruiser that has punch you can do better.

Stick around, join in the discussions, and make CHR a better place from you being here! Looking forward to watching that coupe come to life!

Mike ----since your up in ne mich--------contact Pat Mc Carthy-long time member on here and has a shop doing very exacting work--------

Also, that Summit free shipping doesn't apply to blocks and may cost you a couple hundred dollars more. And I dought that the cam bearings are align bored as all the holes/journals are different sizes.

Originally Posted by jerry clayton

Mike ----since your up in ne mich--------contact Pat Mc Carthy-long time member on here and has a shop doing very exacting work--------

Also, that Summit free shipping doesn't apply to blocks and may cost you a couple hundred dollars more. And I dought that the cam bearings are align bored as all the holes/journals are different sizes.

What kind of shop (what kind of work does he do) and where is he located?

I have not purchased the gears for the rear end yet so they can be what ever suits my needs best once I get to that point. Once I can get some reassembly work done on the car I will be able to tell how large of a tire I am going to use. To be honest I hadn't even thought about the gearing much yet. I know I said 4:11 early on but that was pretty much just a minimum and the original start in my plan. The engine is currently 95% complete so that probably won't get changed. If I find that it is not exactly what I was hoping for it can be a project for next winter to change the cam (one is truly never 100% done with a Hot Rod correct??, there is always something better or something to do. lol). As far as the tranny goes the reason for the 700r4 is that is the one I have (what came with the car). All of the frame work (getting it to fit) has been completed, drive shaft is built, etc. We are just going to go through it and beef it up. My plan is to put stall converter in also (which we will size out once we know the tire size, gears, etc.). This car is being built for cruising in town (mostly in the the lower gears). The closest highway to my house is about 2 1/2 hours away so it probably will never see the highway. I love to hear the sound of an engine coming down the road so I have a tendency to cruise at a little higher RPM then most.

It was a little shocking to hear that apparently almost everything I did was wrong for my build (camshaft, gaskets, carburetor, intake, balancer, pistons, transmission, etc.). Even more shocking (and what I expected to get the most grief from) was the fact that I was putting a Chevy power plant in a Mopar and nobody said anything, ???

I was also surprised that nobody seemed to be to interested in the rotisserie unit I built to aid me in the restoration process. I thought that it was pretty cool. The people I know who have restored cars around here don't have one. I have never had one before but it has made my life so much easier so far. Restoring this car is just one of my hobbies that I enjoy. It brings me a lot of peace of mind to be able to go into the shop and work away with my hands (which I don't get to do enough at work any more). I try not to sweat the small things. Like I said before this project is supposed to be my down time and my get away from the craziness of everyday life. I will probably continue to post on my build because I enjoy sharing my experiences with others, but I will just be more guarded now.

Originally Posted by mprevo

I enjoy sharing my experiences with others, but I will just be more guarded now.

I'm sorry to hear that. What I hear you saying is that you don't want to know the truth.

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Originally Posted by techinspector1

I'm sorry to hear that.

Hey Tech, take a look at post #26.

Originally Posted by mprevo

Even more shocking (and what I expected to get the most grief from) was the fact that I was putting a Chevy power plant in a Mopar and nobody said anything, ???

Well, I was going to say something about that... but people put Chevy engines in these old cars all the time, usually because they're cheap and easier to install or just had one laying around. But when I first saw the thread I was thinking how cool it would be if you were dropping a late model fuel-injected Hemi in there!!! I also understand it's your car and we sometimes have to go with what we've got. It's all good. Cool car! I look forward to your progress.

Pat McCarthy---Bay City Mi-member here, face book,and web site

Rotisseri-I've had one for years and lots of old timers have them-especially anyone doing old barn finds--------

You can back off on camshaft and probably change it out in less than a hour-----get 3.70 to 4.11 gears-if you want revs for a couple miles run it in 2nd gear

Nothing wrong with a double pumper if they are big enough to run in the primaries and sec come in late---------there are also some high cfm vac sec carbs now that work nice-----

Originally Posted by jerry clayton

Nothing wrong with a double pumper if they are big enough to run in the primaries and sec come in late---------there are also some high cfm vac sec carbs now that work nice-----

Jerry, you must not have had your coffee yet when you wrote this. When you step on the loud pedal with a double pumper, you get all 4 bores balls to the wall at one time (there ain't no secondaries comin' in late) and if there are insufficient revs at that point, the motor will load up and nose over, that's why the minimum 3K converter. And this chap needs another 500 rpm (3500 stall minimum) to get up on the cam.

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Originally Posted by techinspector1

Jerry, you must not have had your coffee yet when you wrote this. When you step on the loud pedal with a double pumper, you get all 4 bores balls to the wall at one time (there ain't no secondaries comin' in late) and if there are insufficient revs at that point, the motor will load up and nose over, that's why the minimum 3K converter. And this chap needs another 500 rpm (3500 stall minimum) to get up on the cam.

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I also have not purchased the carb yet. The one I listed is what was recommended by the people who gave me the original plan/parts list. What would be the best/most suitable application for me?

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