VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 235 Swap Advice

Hello to all.
I am in the process of installing a 62 Chevy 235 into my 1942 3/4 ton pickup. I am using the flywheel, generator, dist. & starter from the 235, and the bell housing, clutch fork, throw out bearing, clutch (new) & pressure plate from the 216. Needless to say the truck is being converted to 12 volt.
I am aware of the issue with the short shaft water pump. I believe the 235 I bought already has the short shaft WP installed. I also have all the parts needed to convert the truck to 12 volt (coil, gen, dist, volt reg, battery, etc. I know I will have to install a voltage reducer for operation of the fuel gauge.
Aside from the things I've mentioned above, am I missing anything else that will be needed to complete this engine swap? Any and all advice or comment will be appreciated, especially from those who have already made this swap. Thanks in advance.

Did you check to see if the 216 pressure plate will bolt up to the later 235 flywheel?

Some of the 42 pickup clutches were large, near 11". That 62 flywheel may not take that large of a pressure plate or clutch. You could use the 62 flywheel with the pressure plate and clutch on the back of the 235 engine, but you will give up that large truck clutch.
You might want to use the 42 flywheel, pressure plate and clutch and use the original 6 volt starter to spin it. It will do fine as long as you don't crank it for long periods, just shorts bursts.

Thanks for your reply.
I checked it visually and it looked like they would mate. Before I install the clutch I'll double check alignment of the pressure plate holes. The 42 3/4 to does have the larger 11" clutch
Tom

Thanks for your help.
I measured the two pressure plates and their overall diameter is within 1/8 inch. The primary difference is the number of teeth on the start gear. I counted 168 on the 1962 235 flywheel, and 140 something on the 216 flywheel. Both starters have 9 teeth on the bendix gear, and the gears are about the same diameter and depth.
I did want to keep the larger clutch, so I will most likely go with the 42 clutch components no matter which flywheel I have to use. If necessary, I'll use the 42 starter and flywheel but, I'd still like to convert the truck to 12 volts.
If necessary I suppose I could set up a system to start at 6 volts and run at 12 volts but, that could get expensive and complex.

i have my 39 converted to 12 volts . it is hooked directly to the 6 volt starter & no problems . i think the 6 volt starter is built heavier than the 12 volt one ! i did use voltage reducers on the 6 volt gauges . also i put a brand new wire harness in it . also i used an alternator , so no need for a voltage regulator , as that is built into the alternator. frank

p.s. somewhere - maybe on stovebolt there are easy directions for the conversion .

Frank:
Thanks for the advice on the starter and 12 volt conversion. I may have to go with the 6 volt starter cause the flywheels and pressure plates were different. Therefore, I had to install all of the 42 clutch components on the 1962 235 engine. I now have it just about ready to go back in the truck.
Both of the starters I have on hand have 9 teeth on the bendix. If the throw length is the same, I might be able to use either starter. The only reason I'm reluctant to mount the 12 volt starter is that the two flywheels had different numbers of teeth. However, as long as the 6 volt starter works OK on 12 volts, I'll start with that one. Tom

yup , do not mismatch the ring gear to correct starter ! p.s. i wish i would have put a new ring gear on the flywheel when the motor was apart . oh well.....................frank

Frank:
Thanks again for the advice.
BTW, did you change out your oil pressure gauge when you put in the 235 or, do you just run it pegged? If you changed out the gauge, were you able to get a replacement gauge with the greater range that also fit into the gauge cluster?
In addition, do you run your 12 volt alternator driven system through the amp gauge, or is it wired differently from the original 6 volt system? As you can tell from my questions, wiring is not my strongest skill.
Thanks once again for your input.
Tom

I did the same thing you are doing. I put a '62 235 in a '46 3/4 ton and converted to a 12 volt system. Some thoughts that come to mind.

I tried the short shafted water pump and had overheating problems even with a recored 3 row radiator out of a two ton truck. I attributed this to the low position of the short shafted pump. I went to one of those adapter plates that allowed me to use the 216 water pump (puts it in the correct position in relation to the radiator) and it eliminated the overheating problem.

I used the 216 flywheel, clutch, clutch linkage, etc along with the 6 volt starter. Starter works fine. I reversed the ring gear on the flywheel to get some good teeth for the starter to engage.

If you want to add original accessories like a radio or heater you will have to get voltage reducers to use them.

Accelerator linkage will have to be changed slightly.

The old horn works fine on 12 volts.

I used an oil pressure gauge out of a '46 GMC (GMC's run with higher oil pressure than the 216's). This compensated for the higher oil pressure in the 235.

Definitely keep the 6 volt starter with the 6 volt flywheel (139 teeth) and the 12 volt starter with the 12 volt flywheel (168 teeth). Even though there are 6 teeth on each starter, the pitch of the teeth are different. Changing the ring gear is one way to use the 12 volt starter on a 6 volt set up, but the 6 volt starter will do fine on 12 volts as long as you don't crank it for long periods of time.
The amperes gauge will work fine with the alternator. It's all you really need because it will show charging when the alternator needs to charge and will stay in the straight up position when the the alternator is not charging. It will never read to the minus side unless the lights or a radio are on with the engine not running. I'd suggest keeping the amp gauge as opposed to installing another type of gauge that won't match your cluster.
In the older 30's and 40's trucks, a high engine fan is the way they are designed to run cool. Lowering the fan isn't as effective. Another choice is an electric fan up high on the radiator that can be turned on with a switch when you need it.
Sounds like you've got the rest worked out! Good luck!

http://www.stovebolt.com/techtips/12_volt_conversion.html

copy & paste or click on link this address for more info .

i let the oil peg out - works fine . i used a voltage reducer on the fuel gauge ( w / new float unit in tank ). i want most things to look & be original . frank

p.s. i also bought a " custom replica " wire harness & installed it . that 6 volt wireing is double strength vs 12 volt wire .

This site, and you guys, are great. Excellent information and advice which will save me a great deal of time, money, and effort in completing this swap.
BTW, if I have not yet mentioned it, the 1962 235 I bought came with Fenton headers, Offenhauser dual intake, and two Rochester carbs (and linkage). All of these are in good shape and, will be used in the swap.
I have to agree concerning the replacement of the wiring harness. I will also use voltage reducers for the gauges, heater and other accessories.
It also makes perfect sense to change the 216 flywheel ring gear out to use the 12 volt starter. However, if the 6 volt starter will work OK, I'll most likely stay with that, and trim some cost.
Using the 47 GMC oil pressure gauge is an excellent bit of advice. I completely forgot that GMC engines ran higher pressure. I'll try to track down a GMC gauge and make that change.
Thanks again for all of the valuable advice and comments. It is truly appreciated. I'll post again as the swap progresses.
Tom

the 6 volt starter works as good - i think better than a 12 volt.

Wouldn't the six volt starter burn out eventually using 12 volts on it? I know the six volt starters are pretty tough, and using 12 volts will turn the starter faster, but I would be skeptic to try it on 12 volts. could be I'm not seeing things right.

I guess in theroy it is ok to run the 6 volt starter for a few seconds at a time but most of these that I have seen sooner than later the six volt starter burns up. I would keep the original late model 235 starter flywheel and clutch rather than mess around with six volt stuff, when changing to 12 volts.

As long as you don't crank on the six volt starter for long periods of time, the six volt starter will last for years on 12 volts.

The Mangy Old Mutt

yup i agree , it is more robust than many beleive !
& i have cranked mine pretty hard in the past . frank

My experience, when using the 6-volt starter on a 12-volt system, is that the Bendix spring and the two mounting bolts are abused and tend to break after a short period of use. That is, in relation to the durability in a straight 6-volt environment.

I converted a english built tractor from 6 to 12v to get away from lucas electrics that fail on a regular (daily) basis. I had to use the original starter which worked well for 5 years of almost daily use. As JYD said short bursts up to 30 seconds with 60 seconds between wont cause any trouble.
Tony

lucas electrics

sounds as bad as the lucas brake system - pure problems !

My 1951 Chevrolet cab-over slide back truck that I had for about 15 years was converted to 12 volts back in the 1960's and the six volt starter remained. The vehicle still had the six volt starter on board when I sold the truck a couple of years ago. In all that time I never had a problem with the six volt starter on the 12 volt system.

I converted my 54 wagon 12 years ago ..the 6 volt starter was a great surprize.. sounds great. Patricks Antique trucks has a free How to brochure on 12 volt conversion..His shop is in Casa Grande Arizona.Give him a callblue38