Thread: 1937 Plymouth 5 Window Coupe

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Anyways I still have lots of stuff to figure out yet. The engine is not installed so things can still change. A different cam is not the end of the world and it won't break the bank. I will see what the responses are to my question above and maybe I will make the change while it is still the easiest. Most people here seem truly genuine and very knowledgeable and I appreciate that. I hope that I can learn something and most importantly I hope I can make my Hot Rod the best I can using the advise from people who have "been there and done that".

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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 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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Tech-

I have had carb size/configuration discussions with hundreds of different people of varying expertize of doing engines------

A double pumper has progrssive linkage to the secondaries and alltho they will reach wot at the same point, they are not equally open front and rear-as you drive within the part throttle region, the bores aren't equal.

Double pumper carbs are easier to tune for high performance driving altho vacume sec are easier for pussy/check writer drivers that want to say (insert various quotes here) I got this much horse power--------yep on a dyno wot -----but can you drive it in any of those upper rpm/hp ranges?
A double pump carb can be set up ( I like the 800/850 sizes) so you can drive higher range on just the primaries at a more effient fuel milage/mixture and yet have the secondaries come in the last part of the throttle range without needing to be wide open and/or not getting it til later -the mech sec carbs have the advantage of running richer jets toward the top end and also added power valves to make up for leaner cruising on pri.

I have done thousands of set ups for various vehicles ranging from Grand mas car to road racers, drag racers, hill climbers, etc------I aim for drivability range in the street area and record setting results for the racers-------

Originally Posted by mprevo

If I were to decide to swap the cam out. Would either one of these be a better match for me?

Howards Cams Hydraulic Roller Camshafts 180265-10 - Free Shipping on Orders Over $99 at Summit Racing

or

Howards Cams Hydraulic Roller Camshafts 180245-10 - Free Shipping on Orders Over $99 at Summit Racing

Both of these cams are recommended by the people I bought my parts from?

Nowhere in any of this thread have you told us what the exact static compression ratio of the motor is and you cannot intelligently choose a cam for a motor until you know that. That's why I asked you in post #14 what the block deck height was and you never answered. You need to know either the block deck height or how far the piston is down in the bore with the piston at top dead center (piston deck height). I went back and read where you have used a 0.030" gasket. Can you give me the part number and manufacturer of the gaskets?

Here's the thing: Your stack is 9.015". If the block deck height is 9.015" (zero deck, then the static compression ratio of the motor will be 10.74:1. This is the upper limit that I can figure for you with the information you have provided so far.
If the block deck height is 9.025" (0.010" piston deck height), then the static compression ratio of the motor will be 10.49:1. This is the lower limit that I can figure for you with the information you have provided so far. Either of these static compression ratios will require a cam with at least ~222 degrees intake duration @0.050" tappet lift or a cam with at most ~238 degrees intake duration @0.050" tappet lift. Disregard exhaust duration, it plays no role in figuring the cam you need. What you are interested in knowing is where the cam closes the intake valve.

If I were building your motor, I wouldn't have built it with this much static compression ratio in the first place, but if I did, I would choose a cam in the middle of this range, ~230 degrees intake duration @0.050" tappet lift. I would also choose a cam ground on a 112 degree lobe separation angle or even a 114 degree lobe separation angle in order to try to have a little intake manifold vacuum for power brakes. I predict you'll have to use hydroboost off an Astro Van anyway, but having a little manifold vacuum to provide a signal for the carburetor is a good thing.

You cannot use a smaller cam than 222 because the intake closing point of such a cam will make too much cylinder pressure for use on pump gas and you'll detonate the motor to destruction. Cruising rpm's for a 230 cam will be in the area of 3600-4400, so again, the 700R4 is not the transmission that you want to use, particularly with that long fosdick 1-2 shift. What you need is a TH400, a set of 4.44/4.56 gears and a 3500 stall 10" converter. Don't be fooled into using a 12" converter with the fins bent over, go for a 10" to begin with. Budget $500 to $600.

BOTTOM LINE: You have painted yourself into a corner with your choice of parts.

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Originally Posted by jerry clayton

Tech-

I have had carb size/configuration discussions with hundreds of different people of varying expertize of doing engines------

A double pumper has progrssive linkage to the secondaries and alltho they will reach wot at the same point, they are not equally open front and rear-as you drive within the part throttle region, the bores aren't equal.

Double pumper carbs are easier to tune for high performance driving altho vacume sec are easier for pussy/check writer drivers that want to say (insert various quotes here) I got this much horse power--------yep on a dyno wot -----but can you drive it in any of those upper rpm/hp ranges?
A double pump carb can be set up ( I like the 800/850 sizes) so you can drive higher range on just the primaries at a more efficient fuel milage/mixture and yet have the secondaries come in the last part of the throttle range without needing to be wide open and/or not getting it til later -the mech sec carbs have the advantage of running richer jets toward the top end and also added power valves to make up for leaner cruising on pri.

I have done thousands of set ups for various vehicles ranging from Grand mas car to road racers, drag racers, hill climbers, etc------I aim for drivability range in the street area and record setting results for the racers-------

Sorry Jerry, I'm just visualizing solid linkage.

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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.

A lot of people with many years of experience are giving you some very good advice. You'd be a fool not to listen to what they say an put their suggestions into practice. The biggest mistakes novices make are: cam too big, carb too big, heads too big. Bigger is not better! Bigger is dumber! You have to think of an engine as a system of interrelated parts that must work together efficiently if it is going to perform to expectations. Mistakes are disappointing and expensive.

I have definitely been listening to what everyone has to say. I have been giving lots of thought to everything. I also have reached out to other people I know. I have began to put together a revised plan with the drive train. I am sure in the end it will work out. Thanks for the advice guys.

I have been watching this thread, and I have a question. I am not trying to start an argument with you, techinspector1, as you have considerably more experience than I have. But I don't quite understand your recommended cruise rpm for a cam with 230 degrees @ .050 duration. Perhaps you can explain that to me because I have achieved different result. My 383 has a 230 cam [CompCams 280 Magnum], AFR 190 heads [68cc chambers], flat top forged pistons w. 5cc relief, 6 inch connecting rods, and a zero-decked block with a .039 head gasket. That equates to 10.6:1 static compression, 8.44 dynamic compression. I know that is somewhat on the edge of what pump gas will accommodate. I had it run on an engine dyno to set timing and dial in the carburetor, and its best pull was 450 hp @ 5200 rpm/468 ft. lbs. of torque @ 4300 rpm. It made the most power with 32 degrees total. It runs fine on 92 octane pump gas, it will cruise all day in overdrive [700R4] at 2100-2200 rpm without ever dropping down a gear to climb a moderate hill. But if you get much too below 1800 rpm, it is going to want a lower gear. Is this because the engine makes so much torque and the vehicle is so light? This is in a '32 Ford coupe weighing around 2600 lbs.

Originally Posted by rumrumm

I have been watching this thread, and I have a question. I am not trying to start an argument with you, techinspector1, as you have considerably more experience than I have. But I don't quite understand your recommended cruise rpm for a cam with 230 degrees @ .050 duration. Perhaps you can explain that to me because I have achieved different result. My 383 has a 230 cam [CompCams 280 Magnum], AFR 190 heads [68cc chambers], flat top forged pistons w. 5cc relief, 6 inch connecting rods, and a zero-decked block with a .039 head gasket. That equates to 10.6:1 static compression, 8.44 dynamic compression. I know that is somewhat on the edge of what pump gas will accommodate. I had it run on an engine dyno to set timing and dial in the carburetor, and its best pull was 450 hp @ 5200 rpm/468 ft. lbs. of torque @ 4300 rpm. It made the most power with 32 degrees total. It runs fine on 92 octane pump gas, it will cruise all day in overdrive [700R4] at 2100-2200 rpm without ever dropping down a gear to climb a moderate hill. But if you get much too below 1800 rpm, it is going to want a lower gear. Is this because the engine makes so much torque and the vehicle is so light? This is in a '32 Ford coupe weighing around 2600 lbs.

As I have stated before, I lean on the manufacturers for actual information about what will work and what will not work. None of what I say comes out of my mind without verification. In the case of posting the cruise rpm for a 230 intake cam, I would refer to the Crane HR-230/352-2S1-8 IG, 108 LSA in the Crane catalog, where that cam is listed as needing 3000-3800 cruise rpm or the Crane HR-230/359-2S-12.90 IG, 112 LSA in the Crane catalog, where that cam is listed as needing 3600-4400 cruise rpm. I have no doubt that the cam you have in your motor should be operated at approximately the same cruise rpm. The fact that you are cruising it at 2100-2200 just means that you are out of the cams operational range and that you would get much better fuel mileage and throttle response with a cam that is designed to cruise at 2100-2200 rpm's.

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Originally Posted by techinspector1

As I have stated before, I lean on the manufacturers for actual information about what will work and what will not work. None of what I say comes out of my mind without verification. In the case of posting the cruise rpm for a 230 intake cam, I would refer to the Crane HR-230/352-2S1-8 IG, 108 LSA in the Crane catalog, where that cam is listed as needing 3000-3800 cruise rpm or the Crane HR-230/359-2S-12.90 IG, 112 LSA in the Crane catalog, where that cam is listed as needing 3600-4400 cruise rpm. I have no doubt that the cam you have in your motor should be operated at approximately the same cruise rpm. The fact that you are cruising it at 2100-2200 just means that you are out of the cams operational range and that you would get much better fuel mileage and throttle response with a cam that is designed to cruise at 2100-2200 rpm's.

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That makes more sense to me now when you put it that way. Basically the cam that is in my engine will work, it will just not be as efficient or responsive if the transmission is in overdrive. I have also done some homework after reading through the comments on this thread and I am 95% that I am going with the 3500 stall and 4:56 gears for my built. That will give me a cruise RPM of 3406 in drive (not overdrive) at 60 MPH (which I probably won't do that much since most of my cruising will in town at lower speeds) . I just need to verify the size of tire I can fit under my car. I believe it is going to be 27" but I need to set the body back on the frame to verify. I have also been checking out the different stall converters available. Does anyone have an recommendations on Manufacturers (or ones to definitely stay away from). This will be my first tranny with an aftermarket stall and I don't really have any knowledge of them (all of my other builds have always been a manual transmission). Thanks.

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stall is for setting at the traffic lite and initial acceleration--if you have a trans with decent ratios(not a 2 speed powerglide) you won't and probably shouldn't run a high rpm stall converter for street driven vehicles. If you are racing the car a high rpm stall lets the initial launch be more positive.

A more modern trans-4l60- with a lock up converter will be a better choice for a driven car and better milage--better performance for cruising, etc

mprevo, I agree that you probably don't want the high stall speed given the intended use you've explained for the car. Your 700R4 has a 1st gear ratio of 3.06 (same as the 4L60E), so with 4.56 rear gears your ratio from a light is gonna be almost 14 to one, so 1st to 2nd will be quick. I'd probably drop back to a 2400 to 2800rpm stall speed to make it more street friendly, but that's just my $0.02.