The Stovebolt Site Forums The Shop Area Engine Shop Phantom 235 Head, 3835913?

Checking out my engine numbers on my latest project a 1954, 3604 w/stock 235 just to see if all is original to the truck. The block serial numbers check out ok and the casting and serial numbers tell me Flint, on March 29, 1954.

The head casting number threw me for a loop though. Casting number is 3835913 and that isn’t shown in either the 1929-1954 or 1929-1957, or 1958 parts books.
Finally went to Hemmings list of casting numbers and it comes up 1954-55 only.
Anyone have any stories about the first 2years of the new 235 head and why they changed it in ‘56?
Denny Graham
Sandwich, IL

3835913 head was 1954 and 1955-1st
What is the date casting code?

I'll look up info on the late 55 head (hp also increased).

112hp in 54; 123 hp in 1955-2nd

rocker arms changed

The block was significantly different with respect to the water pump have internal vanes in late 55.

Maybe Pre '68 Dave will have information about changes?

1956 went to electric temp gauge so the hole in the head is larger and is pipe thread.

Haven't had the Rocker Cover off yet Tim. but it had to be March or before because the engine casting number is March and the truck was delivered and registered in April of 1954.
Just thought it odd that it wasn't listed in any of the Chevrolet Parts books.
So what went wrong with the '54-'55 head that they came out with a revision?
Denny Graham
Sandwich, IL

Thanks, Dave

What changed gave it the higher hp?

I haven’t seen any service news for anything past 1955 nor have I seen any engineering features later than ’55.
Been searching since late last night and I haven’t found any reference to the change in any of the literature I have access to. The parts book –1957 just shows the 3836848 head as a replacement for 1953-1957. We’ve all heard how the 848 head is the head that you want to use and I seem to remember comments being made about the difference in this head to the earlier head. I’m sure there were other changes than the temperature port.
It appears the cam geometry was changed often which would account for the higher hp of the later engines but it only stands to reason if they were changing that then they would have also improved the porting.
DG

The higher-compression "848" (3836848) head became available in 1956 (and was used until the "end-of-the-line"). From 1956 onwards, it was the replacement head for all high-pressure 235s (maybe even the 1953 Powerglide 235?).

This style of adapter was/is used on trucks with mechanical (tube) temperature sender (also available at NAPA).

Once again, let's hope Pre'68 Dave adds-to or corrects this.

Even the 'non full-pressure' '53 235 such as mine.

Hey Denny,
I have that same head on my '61. It was on it when I got my truck.

I have to credit this information to Chevgene over at the VCCA. So here is what he had to say to sort things our in my mind:
The 1953 head casting 3708887 dropped the screws for the side cover but still retained the center rocker cover studs. It had a compression ratio (CR) raised to 7.1:1
The 1954-55 first series head casting 3835913 incorporated the four drilled and tapped holes to attach the rocker cover. Intake valve guides are shorter than 1953. CR upped to 7.5:1, 20hp increase over 1953.
The 1956 head casting 3836848 Was the same head as the 913 but now has a pipe thread for the electric temp gauge. CR was 8.0:1
The 1957 head casting same as 1956
The 1958 head casting same as 1956 but CR now upped to 8.25:1
The 1959 to 1962 head same as the 1958.
And as is presented in the parts books the 3836848 head was a replacement for the 1953 to 1962 235. And of course in 1953 the old 216 was still retained in the light trucks so the head info doesn’t apply for that year truck.

So, all I can say is the information clears my head!
Denny Graham
Sandwich, IL

Thanks Denny, this should clear things up. I will stress the point that in 1953 both the splash 235 and full pressure 235 used the same head.

Thanks for the info, very informative thread

Denny,

Is Chevgene referring to car 235 and/or truck 235 when he states that 54/55 had a 20 hp increase over 53? Which two 235 engines?

The two car 235 engines in 1953 supposedly had:
7.1:1 cr (108 hp) - low pressure
7.5:1 cr (115 hp) - high pressure
And, the Corvette 235 supposedly had 8.0:1 cr (150 hp)

The two car 235 engines is 1954 supposedly had (all high pressure):
7.5:1 cr (115 hp)
7.5:1 cr (125 hp)
And, the Corvette 235 supposedly had 8.0:1 cr (150 hp)

Supposedly, there was a 20hp gain between the 1953 Thriftmaster truck 216 and the 1954 Thriftmaster truck 235?

The truck low-pressure 216 engine in 1953 produced
92/85 (gross/net) hp (6.6:1 cr) - Thriftmaster, standard

The two low-pressure truck 235 engines in 1953 produced
107/102 (gross/net) hp (7.1:1 cr) - Loadmaster, H-D COE
108/103 (gross/net) hp (7.1:1 cr) - Loadmaster, H-D conventional

The three high-pressure truck 235 engines in 1954 produced
112/105 (gross/net) hp (7.5:1 cr) - Thriftmaster, standard
110/102 (gross/net) hp (7.5:1 cr) - Loadmaster, standard
112/105 (gross/net) hp (7.5:1 cr) - Loadmaster, H-D conventional

Maybe your head is clear, but my head is spinning.

Was the 3836848 the same for all years? What changes between 56-63 (between 56-58, actually) caused the higher compression ratio?

Is it correct to say that blocks were different and heads the same on the high-pressure and low-pressure car 235 engines in 1953? The crankshaft was certainly different.

It also looks like the car and truck 235s in 1953 used the same head (is that right - 18 bolts on car and truck heads)?

Also, it looks like the low-pressure car and truck 235s used the same style of block (maybe with different casting-codes)?

Hey Tim,
I can't answer you question about the 848 head, I will look in my Service news, but as far as the 53 235, the block, crank, and pistons(cast iron on splash, aluminum on full pressure) are different. The splash engine also used solid lifters and the pressure engine used hydraulic. The splash engine was also used in the big trucks, most likely because of the torque from the heavy pistons.
The main difference between a 53 head and a 54-55 head is that the 53 head is not drilled for the four bolt valve cover.
I use up my 53 heads on 53-62 engines where the customer wants to use a 216 valve cover.

I didn't quote Gene word for word Tim, I just used his reply as a starting point for my own research. The 20 hp info came from the Service News.
I tried to clear the water by noting that this was for the 235 which wasn’t used in the light trucks. I suppose I should have also said that there are a lot of changes going on during that period depending on what the application was.
Gene did address the increase in CR in ’58 for the 848 head and his guess was that they might have just shaved the head.
The early 235 head, i.e. 1953 3708883, head had the combustion chambers reworked according to the Service News for that year and was being used for all three applications of the 235. This really was a transitional year for the Stovebolt. From what I gather, even though the Load Master and 3speed pasenger 235 block was upgraded it still remained a splash oiler. The new block uses the new head and all of the blocks were strengthened supposedly because of the increase in CR. Makes me wonder if the block wasn’t the same 235 casting they were using in the Load Master, standard passenger car and powerglide. It also seems odd that they didn’t go full pressure with the standard 3speed passenger and Load Master engines at the same time as the powerglide engine. According to the Service News they were using the new rods and cranks in this engines.

This can get very convoluted and requires more comparison of the block casting numbers. I just don’t have the time to do that now.
Denny Graham
Sandwich, IL

The head that came with my '50 1/2-ton is a 3835913. It's pretty beat up and I don't have a plan for it, except that I'm working on getting a 261 to drop into my truck and I've considered adding an 848 head for compression. If there's no difference other than my 913 and the later 848 except for the threaded temp gauge hole, should I consider rebuilding this head for my 261?

If you use the 235 head a 261, you most likely know you should drill additional coolant passages in the head to match the additional coolant passages in the 261 block? Use the 261 head gasket as a template for drilling the six holes in the head.

Great advice, thanks!
n

because of the torque from the heavy pistons

The what?

The splash engines used cast iron pistons.