project 1951 Pontiac Chieftain

[PhilA]

In this case no, it just has a water jacket and that's about it.

 

Phil

[Zelandeth]

That is odd... really looks like someone has bolted eight Briggs & Stratton side valve engines together

 

(Which 805 Road King on YouTube did to make a four cylinder version).

 

There's not much soot in there, must have been running pretty clean by the looks of it.

[PhilA]

It's been running a bit rich, but overall it's pretty clean. Both primary jets are adjustable externally, which is nice. Colortune territory.

 

Oh, and there is quite a bit of variance across the cylinders because the manifold hadn't been tightened correctly and wasn't sealing well across all the ports.

 

 

Phil

[PhilA]

I had a think, it turns over using my 3/8" drive ratchet on the harmonic balancer pulley.

 

It's overall ok, a little tight in a few places so I have a feeling a set of new bearings were fitted without the crank being ground and it's slightly oval. Not so bad that it binds up hard but it's may also just be the points where I'm moving the pistons the most.

 

I think the bottom end can stay buttoned up (plus it doesn't leak), the oil strainer should be ok. It'll get an oil change and I think there we'll be good to go.

 

Gearbox does worry me though. There's silicone sealant around the oil pan. If any of that been ingested that could very well be the changing issues. I found a (crappy quality, the guy liked to hang the camera out the window too much) video of someone driving a Star Chief with an automatic. It changed smoothly 1-2, flared up and dropped to 4. Apparently another common fault when the valve block gets leaky.

These boxes seen to be really finicky about pressures- factory spec is within 10psi for most values, some closer than that. I'll have to get a gauge, some brake flexi and hook up to see what pressures I get. The brake bands will also need adjusting. That's more of an on-the-car item, being set by RPM and drag measurement.

 

Phil

[hairnet]

never seen straight eight like that

 

cool

 

literally flat head

[PhilA]

 

Pistons! Valves!

 

 

Phil

[spartacus]

Mega!

It is huge, I'm surprised it doesn't weigh more as a unit with the 'box. I'm sure an SBC with THM350 weighs more.

Are you re-fitting on your own, or getting help?

[PhilA]

That combo weighs 165 lbs less than this does.

 

I'm going to put it back in by myself, it's remarkably straightforward with the front of the car removed.

 

Also, there's something in the GIF of the engine that I want the eagle-eyed of you to try and spot that's wrong.

 

Winner gets a hundred Internet points.

 

Phil

[egg]

That engine is amazing.

 

'everything in teh past was better'

 

well it just was, wasn't it?

[mat_the_cat]

Number 4 cylinder, the valves appear to change the opening order?

[Sir Snipes]

3rd cylinder from the front has some funky valve timing?

[PhilA]

You are both on the right track, but not correct.

 

The odd order is a trick of the camera shutter speed versus how fast it spins over on the starter (6V starter, 12V battery). I had to slow the GIF down to 50% to make it display better.

 

Phil

[Sir Snipes]

Cylinder nearest gearbox seems to be missing a valve?

[PhilA]

Cylinder nearest gearbox seems to be missing a valve?

Bingo! The exhaust valve was stuck open. I had heard the engine down on one pot the last time I ran it, that'll be the culprit.

 

 

I doused it in penetrating oil and gave it some gentle persuasion with the handle of my lump hammer. The bolt holding the manifold on goes through to the water jacket, was leaking past the manifold and it had drawn water through and gotten onto the valve stem.

 

That cleaned off, it moves freely again.

 

I've been told the copper gaskets are not reusable (despite this one looking like it's been used several times).

 

Top end gasket set and I think I'll be good.

 

Phil

[PhilA]

That engine is amazing.

 

'everything in teh past was better'

 

well it just was, wasn't it?

Well, consider The design of that can trace it's roots to the early 1930's...

 

It's before 1986; acceptably early.

 

Phil

[Inspector Morose]

Nah, the copper gaskets can be reused - they do need anealing though before reuse. That’s as long as it’s complete. Sadly on this side of the pond straight eight copper gaskets are a little thin on the ground. I had to do a top end on a Packard super eight a while ago and the only way was to get a new one custom made. I did find a place near to me that can do custom copper gaskets and looking recently, it seems that they are still around.

[PhilA]

It's copper on the block side, that only folds around to form the fire ring. The top side is some silver tinfoil stuff.

 

Funnily head gaskets after available for these- $64 a pop. Not too bad considering they're custom made.

 

How hot you gotta get them to anneal the copper?

[Inspector Morose]

Cherry.

[PhilA]

It looks to be some sort of composite stuff inside. I don't think it'll tolerate cherry red heat, so new gasket is probably the way to go.

 

A copper gasket that's never been heat cycled doesn't need doing, right?

 

Phil

[320touring]

Superb work, looks like you're powering through it.

 

I need a larger engine.

[Inspector Morose]

Nah, should be soft enough when new. The one we had made (the old one had blown between cylinders) was pure copper - I had no clue as to whether that was original or not but beggars can’t be choosers. It had to come apart again, strangely enough for a stuck valve and the guys who made the gasket told me just to anneal it by getting it cherry and letting it cool by itself. If you quench, it’ll just make it brittle and hard.

 

$64? Bloody hell, at those prices it’s a no brainier!

[PhilA]

I'm going to go get a new blade for my scraper, clean the head and block up, probably whiz the paint off and redo it in green. I'm thinking of getting some John Deere green, and some Windsor Blue engine paint and mixing them to get the correct shade green for this (or something close, at least).

 

Phil

[PhilA]

Went to AutoZone.

 

Bought a box of 100 #9 razor blades. 10¢ a pop but it pays dividends to be able to replace them regularly when going over coolant passages and bolt holes.

 

Broke out the brass brush. Going to need a new one soon.

 

Looking pretty good actually.

 

Gave these pistons a quick wipe over with carb cleaner, then soaked them in protective oil.

 

Finally re-coated the head in protective oil for the night. Big storm rolling in, put a stop to working outside.

 

Phil

[DeeJay]

The rate you're going at it'll be painted, back in the car and ticking over by Wednesday.

[PhilA]

Not quite. Gotta order some bits from That There California.

 

But, soon. And yes, there will be engine startup on the floor. Because.

 

Oh, and I did a bit of research. There's a video of one of these engines being run to death in the dark, and no- it doesn't make flames at full throttle with the exhaust removed from the manifold. So there won't be that.

 

Phil

[DeeJay]

Are you going to give the head the Dave numbers treatment (wet and dry glued to a flat bit of worktop)?

[PhilA]

Nope. Straight edge shows it to be true. It'll simply be cleaned with the blades. That's as good as it requires.

 

Don't forget, the service manual states the head gasket is an "it's taken to overheating so change it at the side of the street" item. It wasn't leaking before and it wasn't particularly clean, but that was good enough.

It's also only 6.5:1 compression so it takes a fair bit to make it unhappy.

 

Phil

[Clanger]

Not quite. Gotta order some bits from That There California.

 

But, soon. And yes, there will be engine startup on the floor. Because.

 

Oh, and I did a bit of research. There's a video of one of these engines being run to death in the dark, and no- it doesn't make flames at full throttle with the exhaust removed from the manifold. So there won't be that.

 

Phil

CA help available - ya know, just in case you don't have phones n internetz down there in Napoleonville...

[PhilA]

I'm not in Napoleonville.

 

I'm in Larose.

 

Napoleonville is up Hwy 20 out of Thibodaux.

 

 

Phil

[Junkman]

Mega!

It is huge, I'm surprised it doesn't weigh more as a unit with the 'box. I'm sure an SBC with THM350 weighs more.

Are you re-fitting on your own, or getting help?

 

Please don't take this as criticism, or patronising you, or any other dismal shit that's ripe on this forum lately.

 

The SBC was designed by Ed Cole within 6 weeks.

Arguably he had a lot of knowledge built up in preceding years, which he deployed on the design of the Chevy V8, but he was an excellent engineer in his own right.

 

The fundamental technology he pioneered with the Chevy V8 was thin wall casting. In mid 50s America, casting precision had been developped to an extent, that it allowed Cole to apply it for mass production. This fact is one of the cornerstones why the SBC became the success it became, and let's not forget, that this very success is it being the most produced ICE of all time.

 

Now, back then there was fierce competition between the individual GM Divisions, but over a relatively short period of time, each of them came up with their own design of a thin wall casted OHV V8. This went on until 1968, when Cadillac unveiled a clean sheet designed 'ultra thin wall casting' 472, which grew to the legendary 500 (8.2 litre) in 1970. That engine is arguably the best engineered septic V8 ever built. Few people know that it actually weighs 20kg LESS than a SBC.

 

Phil's straight 8 is a remnant of an era far preceding this and even in 1951 it was decidedly dated. That engine can trace its roots back to prohibition era 1932.

It took Pontiac until the late 50s to catch up with what was merely deemed current at the time. This should give you an idea what kind of a palace revolution it was when Lee Iacocca pressed for the legendary GTO in the early 60s.