HA/GR, gmc 235 or flathead rebuild expense?

[vectorsolid]

I'm in the "accumulate parts" mode. I have access to the 235 and a decent amount of flathead stuff. Having never built either, and never owned either, I'm outta the loop here.

Here are my current options for an HA/GR driveline.

a) 235 w/trans and a rear end $600, needs overhauled.

b) 24 stud 239 flathead with trans and rear end, needs overhauled, $600

c) yet another buddy wants to sell me a 1954 chevy truck with a 235 and 4 speed in it. Runs like a top. $3000 truck is not all that bad, but needs a lot of attention.

The dilemma as best as I understand it.
Both engine and drivelines will come with everything required, but both need to be gone through.

I can get the truck for $3000 (maybe a few bucks less), and gut the entire drivetrain out from underneath it and build my rail. At that point I have a USED engine and some good sheetmetal. Or, for the same money, I can pop $2400 into either engine and have a fresh overhauled engine. And the cool of the flathead kinda trumps (for me) the 235.

I'm having trouble rationalizing taking apart a good truck... :o It could be a daily driver.

Here's where it gets really off the wall. My good buddy with the flathead stuff, is the machinist and the shop manager. He will build this with his personal stock. He's built dozens of flatheads and knows his stuff. We sat down and went through a few books and put together a more bad ass flathead, and it ended up being $5500 done and on my door step. Here's the rub... He's my buddy, and says, "man, that's always been my dream, to build this engine the way we spec'd yours... that's my dream engine" he says to me.

He also wants to build an HA/GR with a flatty. I want him to have the dream engine if we're gonna build one, not me. So know I'm torn on that too. But I know he could use the money from the build... *AAAAARRRRGG* what the heck am I supposed to do?

I don't want to irritate a bud, I don't want his dream, I want him to have his dream, and I'm having a mental problem stripping down a good running old truck. And I bet it costs me more than $3k to overhaul that 235. And I have to pay to have it done. I'm not "that guy" with the 235 knowledge.

Now what?

And part of the original fun, at least for me, was going to be able to say I knocked this dragster out for less than 2 grand. Starting to look like 6-7 grand... You know what you can get for 7 grand in a regular F.E.D? Some NICE stuff....

Why does everything need to be so complicated? I think this was more of a rant out of frustration than an actual question... :o

[Godzilla]

I built a 235 chevy (1955 model) recently. There are quite a few problems with this engine that can get expensive to try to fix. I gave my engine builder unlimited time and funds to see what he could come up with. It took him almost two years to get my engine built and $6800. Everything was made special for it and that translated into time...that I could have been racing. If I had it to do over...I wouldn't. Zilla.

[iagsxr]

I built a 235 chevy (1955 model) recently. There are quite a few problems with this engine that can get expensive to try to fix. I gave my engine builder unlimited time and funds to see what he could come up with. It took him almost two years to get my engine built and $6800. Everything was made special for it and that translated into time...that I could have been racing. If I had it to do over...I wouldn't. Zilla.


Would you care to elaborate on specific problems? I have a 1960 235 in my possession. Right now I'm basically storing it for the owner with the understanding I may want it. Can give it back if it's not what I want.

[Godzilla]

To answer your question...it may be easier to list what parts were put into the engine to fix the problems...and not go into the why: offest the crank to 250 CI, Groden aluminum rods, Ross 13.5:1 lightweight pistons, Perfect Circle rings, Melling HV pump, Pete Jackson billet steel timing gear set, head ported and polished, special built pushrods for length, special built Manley stainless valves on exhaust and intake for length, Comp beehive valve spring special for length; ARP studs for mains and head, Fluid dampener, Schneider solid cam .600/309, corvette solid lifters, Mallory electronic distributor, SBC mini starter and custom SFI flexplate.

Very hard to get this thing balanced...and enough clearence inside the block to clear the custom 6.385 BBC connecting rods. I got to know the engineers the companies that made the parts for this build very well over the two years. Everything was one-off and came with no part numbers. I hope this helps. Zilla.

[17dracing]

235 is chevy !And parts are everywhere for them !!! 236 is GMC ,and pound for pound if you can find a GMC 302 ,1954 to 1958 motor use it !!! I have a 235 in my car and it is awesome !! our lakester has a GMC 302 ,1954 motor bored out .125 to make a 322 cu.in. motor and it is wicked !!!! Then we have a couple more 302 's for future projects !!!!Any ways Good Luck on your build !!!!

[17dracing]

Also a quick note if the truck has original chassis under it , it will have the enclosed drive line !!! Not good for these cars !!! More work and more money !!!!

[CrkInsp]

Zilla,
How did you go about balanceing that 235 that was so much trouble?
I've been around these things (I6's) for a long time, with many different combinations and haven't seen that problem. Under or over balance???? What componet was the problem?

[Godzilla]

The combined weight loss of the new rods, pistons, pins and rings were equal to the weight of two of the old stock rods and pistons. The journals were built up and offset ground to the diameter of a BBC and the fillets were cut back. Have you built an engine like this and tried to balance it? If you have and didn't have any trouble then we should have had you do it..........Zilla.

[348chevy]

First off if the pickup is pre-1955 it has babbit in the connecting rods and a splash oil system not good. I wouldn't take a good driving pickup and waste it for the drive train. You can put a saginaw 3 speed and have an open drive line and a lot stronger trans. Get a catalog from Patrick's out in AZ. The catalog will tell you all you need to know about the 235. Without all that Zilla went through you can easily make 175 HP with a 235 a lot cheaper than building a flathead. A flathead will cost at least $5500 to $6000 to get the same HP as the 235. Don't use a reground cam because you need as much lift as possible because the rocker arms are not a good ratio. Parts for the Chevrolet are cheaper and more available than for GMC. The 236 GMC is useless engine, it has a bad head design, shrouds the valves and won't breath. Go a 270 GMC, much more available, with some high compression pistons a cam in the 270 duration and .500 lift use Chev small block valves and grind some in the pocket and unshround the intake. That engine should easly make 225 HP. The drawback to the flathead is that you can't make it breath because the cam runs the valves which have no multipying factor of rocker arms. The cam lift is all you get. You have a weak lowerend and exhaust that come through the block with the center cylinders sharing the one center port. The flathead was a cheap engine to hotrod in the old days and the parts were a dime a dozen. Not so in 2008 parts are like pure gold but they are avaiable. You can make a flathead that will make power but it will cost you plenty. How much are you willing to pay for romance? Arkus Duntov invented the ARDUN heads for the flathead, which made it a hemi, which addressed all the problems I just said. There are guys who don't care and run flatheads anyway. 2B beat me 3 out of 4 times with a flathead. He popped out of the hole and I couldn't catch him on the top end. 2B's flathead is a premier running flathead. I think if he went to 3 carbs he would be even faster on the topend, I hope he is not reading this.:DRoy

[CrkInsp]

Zilla
I understand you had a problem. I'm just trying to learn what caused the problem.
After seeing what you did I now understand, some what. I have avoided the BBC bearing idea in favor of SBC or something in that area. How much did you have to take off the cam for clearance?
How does the car run, ET & MPH? What kind of 60' times?
Bring it to Tulsa and run with The SDRA next year. They welcome Ha/Gr cars. Your not that far away, come on over and join in the fun.
CrkInsp

[vectorsolid]

Thanks for the input guys. :)

348chevy, I swung the deal for that truck tonight...:o It'll be fine. I don't need to run in the 15's to have a good time. I think our spirit is in the right place with what we've found. And I can put some other crap 307 in that truck and make it work, which means that REALLY, I got my driveline for free.

And THAT is cool. Even if the car ain't fast when it's done. and for ET bracket racing, that's all good with me. :)

[vectorsolid]

What do I look for to make sure what I have is the newer High-pressure oil system and not the oil dipper?

Here is the information I found on some Chevrolet in-line stuff.


In 1941, a 235 cubic inch version of the 216 engine was introduced for use in large trucks. This engine also had a "dipper system" as described above, in reference to the oiling system, as in the 216.

The 235 in³ (3.9 L) version was added to cars in 1950 to complement the new Powerglide (http://en.wikipedia.org/wiki/Powerglide) automatic transmission (http://en.wikipedia.org/wiki/Automatic_transmission). Hydraulic lifters were used in the Powerglide 235 and a fully pressurized lubrication system was introduced in 1953, but only in cars ordered with the "Powerglide" transmissiion. Two versions were used in 1953 cars - a solid-lifter version with 123 hp (92 kW) for standard transmissions and the hydraulic-lifter 136 hp (101 kW) version for Powerglide use.
From 1954 to 1962, the high-pressure 235 cubic inch engine with mechanical valve lifters was used in trucks. From 1956-1962, all 235 cubic inch engines used in cars had hydraulic lifters.
It is interesting to note that the original 1953 Corvette engine was the high-pressure 235 cubic inch engine equipped with mechanical lifters. A 150 hp 235 engine was used in the 1954 Corvette and into 1955 (until they were all sold). The Corvette 235 was equipped with the same high-lift camshaft as used in the 261 truck engine.

[348chevy]

Well now that you've committed or your wife might say you need to be committed. Go to one of the national book stores and order California BILL'S CHEVROLET, GMC AND BUICK SPEED MANUAL THE 1954 EDIITION. It is certainly a useful book and also be sure and get Patrick's Cat. The phone number is [520] 836-1117. These will save you lots of time in research. Good Luck!:)Roy

[nexxussian]

The 'splash oil' vintage engines will have a kidney shaped tin plate on it (IIRC on the driver's side) in the middle of the block. It is held on with 3 screws.

[vectorsolid]

The 'splash oil' vintage engines will have a kidney shaped tin plate on it (IIRC on the driver's side) in the middle of the block. It is held on with 3 screws.

IIRC...what's that?

Got a comparison pic?

[Ron Golden]

IIRC: If I Remember Correctly

[vectorsolid]

IIRC: If I Remember Correctly

Look at you geezers using the "lingo"... ...lol...:D

Ron, my buddy didn't make it back your way. I was bummin, I said you gotta stop by, this guys knows his shite! :)

[nexxussian]

The newer full pressure engines don't have anything there really (well, a tap to the bypass filter, but no plate).


Oh, a splash oil engine (if still in the original vehicle) will also have a 60 or 80 psi oil pressure gauge, splash would have 15 or 20 Psi for the guage.

I'll see if I can locate a pic.


Eh, what's that sonny, whadda ya mean 'geezer'??:p

Edit: that would be a 'full pressure engine would have a 60 or 80 Psi gauge':confused::rolleyes:

[64 DODGE 440]

Look at you geezers using the "lingo"... ...lol...:D


WTF.......we're just old.......we ain't dead.:cool:

[nexxussian]

No luck on the pic of the oil reg plate, yet. I'll keep an eye peeled.