rebuilding 350 sbc - first timer

Schnitz · MILTON, ONT

rebuilding 350 sbc - first timer

hemi43 · ONTARIO

Looks like a good donor for a rebuild.
Even though the bores are not scored, measure them to see how much taper they have. Most wear will occur 1/2 from the top. Any more than .003 and you should rebore. If they are within spec, I would still deglaze the bores and throw new rings and bearings in.
If it's going into a 1946 car, then make sure you have a 1970 or older block. If it's newer, don't use it or you will have to use all the emission controls that came with that engine.
What type of transmission will you be running and gear ratio? That intake is for higher RPM.
With aluminum heads, you will have no problem using regular 87 octane fuel.

Schnitz · MILTON, ONT

I'm trying to figure out the year of the engine.

Here's a picture of the engine code and block casting number.

I can make out the last 2 characters "HS". The only reference I can find to HS is a 69 Camaro LM1 with a TH350 auto, 4 barrel , hydraulic cam with 255 hp.

It looks like there is a character before the HS but I can't find any other codes with HS in them.

-- Edited by Schnitz on Tuesday 31st of December 2013 07:32:02 AM

-- Edited by Schnitz on Tuesday 31st of December 2013 07:32:43 AM

fatchuk · ST MARYS, ONTARIO

Here is where you can find out what your engine is..I can not read the numbers from the pic..

http://www.mortec.com/castnum.htm

I t would be a lot easier to read the numbers and determine the condition if it was cleaned up, It's pretty scungy looking to determine anything from the pics..

Schnitz · MILTON, ONT

It has a 305 with a 3 or 4 speed overdrive and an unknown GMC rear end. If I can retain the transmission I'd like to. As far as I know it should bolt up to the 350 I have. I want an overdrive auto in it for easy cruising.

I can always swap the rear gear for whatever works best.

Schnitz · MILTON, ONT

The casting number is legible - 3970010.
That casting was used from '69 to '79 though so I have to rely on the engine code for more specific info.

fatchuk · ST MARYS, ONTARIO

All the casting number and large harmonic balancer tells me is that it's a 4 bolt..but I could not read the engine number you need to clean it up with a wire brush or some sand paper to be able to read it better..

DaveM · ONTARIO

HS- 1969 350 ci , 4bbl, 255hp, turbo 350, Camaro Chevelle Nova.

And clearly a 2bolt.

hemi43 · ONTARIO

fatchuk wrote:
All the casting number and large harmonic balancer tells me is that it's a 4 bolt..but I could not read the engine number you need to clean it up with a wire brush or some sand paper to be able to read it better..

The picture he posted showing 2 bolts on the mains, would kinda tell me that it's a 2-bolt main block !! LOL

fatchuk · ST MARYS, ONTARIO

Davem said

And clearly a 2bolt.

Guess I should have looked at the first pic eh!! disbelief confuse ...most of those with that casting # and large balancer are 4 bolt.. that has been my experience..but I am old,bald and have too many broken screw drivers in my drawer

hemi43 · ONTARIO

Schnitz wrote:
It has a 305 with a 3 or 4 speed overdrive and an unknown GMC rear end. If I can retain the transmission I'd like to. As far as I know it should bolt up to the 350 I have. I want an overdrive auto in it for easy cruising.
I can always swap the rear gear for whatever works best.

If you're going to build an engine for cruising with an overdrive transmission, then you'll want to get rid of that intake. Know exactly what you want BEFORE you start putting any money into it.

-- Edited by hemi43 on Tuesday 31st of December 2013 10:55:29 AM

Schnitz · MILTON, ONT

I want an easy cruiser that can light the tires when I feel the need.

Doh! I guess I'll be getting new lifters. I turned the motor upside down on the stand and a few fell out.
I pulled the cam because it didn't have any stamping on the end. There are a few numbers between the lobes. It says GM 22, 6964 and F6. From my research it seems as if it is a cam from an L46 or an L82 - 222/222 lift @ 0.050", .450 & .460 duration & 8.5 compression.

I'll definitely but that book and clean a piston.

Schnitz · MILTON, ONT

I'll also check the walls more closely in the morning. And I'll make sure to have the Code restamped.

I want to rebuild it as a project. I know I could just buy one but what's the fun in that? ;)

I really appreciate the help from everyone.

slim · DUNDAS, ONT

It never hurts to mark or scribe your main caps and rods so they stay as matched sets .

Bruce Rossiter · TORONTO, ONT

Schnitz wrote:
- 222/222 lift @ 0.050", .450 & .460 duration & 8.5 compression.

The duration is 222 degrees @ 0.050" and the lift is 0.450/460".

That cam is close to the one that GM uses in their 290 HP crate engine.

-- Edited by Bruce Rossiter on Tuesday 31st of December 2013 10:28:31 PM

-- Edited by Bruce Rossiter on Tuesday 31st of December 2013 10:29:36 PM

Redneck Rydes · TRENTON, ONT & SOUTH CAROLINA

That is NOT a 1969 engine, 1st is 3970010 is backwards,2nd small pad on right front,3rd has boss at top of bellhousing, build date is on right rear will be a letter=month,number=day,single number=year.I am guesing 74 onward 1969 blocks have larger boss for id,3970010 is facing trans,and the extra meat of cast was not on 69 blocks,if you need a 1970 and older engine I have a couple.

Bruce Rossiter · TORONTO, ONT

I checked the information in the Chevrolet by the numbers book and engines with an HS suffix were 255HP 350 engines used in 1969 Chevelles, Camaros, and Novas with the 3 speed turbohydramatic transmission. In 1970, all engine prefixes went to a 3 letter designation.

The prefix V indicates that the engine was cast in Flint Michigan and it possibly could have an M designation in the engine code but its hard to read. If this is an M designation, it could possibly have been intended for a transistor ignition system but that`s just a guess on my part because I can`t see the code too well.

58Chev · ETOBICOKE, ONT

What about the colour? GM Blue started in 1977.

What are the numbers on the rest of the parts?

Intake, heads? Might give an indication of year, if they have not been replaced.

-- Edited by 58Chev on Wednesday 1st of January 2014 09:52:59 AM

Schnitz · MILTON, ONT

The heads are part number 462624.
From what I've found is that they were used from 76-87 and have either 1.94/1.50 or 2.02/1.60 valves.

They are pretty crappy heads from what I've read. Very prone to cracking and they are 76cc. I'll be replacing them.

I don't think the heads or cam are stock for this block.

-- Edited by Schnitz on Wednesday 1st of January 2014 07:13:25 PM

-- Edited by Schnitz on Wednesday 1st of January 2014 07:27:06 PM

hemi43 · ONTARIO

Make certain that it's a non-emission block, or you will be opening a can of worms for yourself.

Bruce Rossiter · TORONTO, ONT

Schnitz wrote:
The heads are part number 462624.
From what I've found is that they were used from 76-87 and have either 1.94/1.50 or 2.02/1.60 valves.
They are pretty crappy heads from what I've read. Very prone to cracking and they are 76cc. I'll be replacing them.
I don't think the heads or cam are stock for this block.

The casting numbers on those heads are the same as the 290 HP GM crate engine. It looks like the cam and heads are off a 290 HP crate engine installed on an older style short block and I'm wondering if this engine was used in an entry level stock car. The rocker cover is a "tall" type cover and the oil breather is the type that is used on stock cars and they generally have 2 breathers on the driver's side of the engine. Also these crate engines aren't supplied with an intake manifold, when new. which could explain the use of an aftermarket intake being used.

Schnitz · MILTON, ONT

I'm going to have to nail down the block code to make sure it's a non emissions block.
The stock car idea does make sense. I'll ask the guy I bought it from.
I drained the oil but not the coolant, my mistake.
I'll talk to the machinist to figure out the engine code and whether he thinks it needs a rebuild. I'm good either way.
I plan to drop it off on Friday.

-- Edited by Schnitz on Thursday 2nd of January 2014 11:22:11 AM

JohnnyBgood · ST CATHARINES, ONT

Cast these blocks for years at g.m. All blocks have a hour or shift and year cast on the side of the block. Should be passenger side. Might have a letter for the month.

Schnitz · MILTON, ONT

Looks like the engine code is CHS with an E108 build date. This means the motor was built in 1978 for a Camaro with an auto and a 4 bbl carb.
So just for my own info what kind of emissions stuff came on a '78 350?
I'm just trying to figure out if this block is a complete waste or can I work with it.

Edit: Emissions parts alone will cost upwards of $300. I can find an older stock block for less "I think".

-- Edited by Schnitz on Tuesday 7th of January 2014 10:50:32 AM

Rochie · LONDON, ONT

If memory serves…."any combination of 28 emission control units may be in place". 1972 was the start of the real emissions war in California and spread east rather quickly. My 1978 El-Camino was pulled over by the MTO Nazi's. I took it to court and explained that I could NOT find exactly which emission control units were factory installed…even with the considerable access I had to GM info(Great Lakes zone Tech training centre, GM apprenticeship training centre) at the college. The justice reduced the fine to $100.00 and said fix what they told you was missing. You might want to consider an earlier block. There have been a number of 350 's on Kijiji and craigslist over the past few months

Rochie · LONDON, ONT

I've known George Zahora for a long while now. He's officially the head of GM restoration archive in Oshawa. He couldn't give me a definitive answer even with the VIN #

JPB · AYLMER, ONT

Rochie wrote:
I've known George Zahora for a long while now. He's officially the head of GM restoration archive in Oshawa. He couldn't give me a definitive answer even with the VIN #

Rochie,last name spelling is Zapora. smile

Rochie · LONDON, ONT

OF COURSE IT IS DAMN FAT FINGERS

Schnitz · MILTON, ONT

Rochie - If your El Camino had the V8 (LM1) then look at the same year Camaro with the 350. It's an LM1 as well.

I spoke to the head MOE enforcement officer.

He quoted from a book he had called the 'Emission Control Systems Manual'. He told me all the stuff his book listed for the '78 LM1 and it coincided with all the emissions stuff listed in the documentation on the GM Restoration website for a '78 Camaro (LM1) - http://www.gmheritagecenter.com/docs/gm-heritage-archive/vehicle-information-kits/Camaro/1978-Chevrolet-Camaro.pdf