292 Engine specs

[Classic1965]

Hi I'm new to the forum and I would like to know the engine specs (piston ring end gap, side clearance, etc. ) for the 292 in my 1965 Chevy C10.

[66Submarine]

According to the book I'm looking at ("MOTOR" truck and diesel repair manual, 28th ed):

Piston clearance .0026-.0032"
Ring gap = .010" compression .015" oil

[Classic1965]

I may need some more specs from you as I'm thinking about taking the motor apart and checking the pistons, rings and bearings while I have the engine out. My truck came from Virginia originally and I got it from a man in Georgia.

[66Submarine]

Oh-those specs are for new parts anyway, not wear limits. FWIW, these engines are very tolerant of wear/abuse and aren't known for problems, so if it's internally clean, mechanically quiet, good oil pressure, etc., you're probably just fine. If all that was/is good, I'd personally probably just run a leakdown (not compression) test on it to check the rings and call it good to go. If you do want/need additional specs just let me know, though.

Also, welcome to the forum!

[TJ's Chevy]

I agree with whats been said...the 292 is a great engine...factory red line is 4000 rpm...and I have done 4800 rpm with it..48 years later and 148,000 miles.

[Classic1965]

I started reading your thread last night TJ. would you happen to know what the compression ratio is for the 292 ?

[TJ's Chevy]

Originally Posted by Classic1965

I started reading your thread last night TJ. would you happen to know what the compression ratio is for the 292 ?

Compression brand new was 8.0.1 and some say it was even as low as 7.6.1, but 8.0.1 is the actual ratio..that's about 130 pounds.

[66Submarine]

IIRC the 7.6:1 ratio was for a later piston with a heavier dish (full circle instead of d-shaped?). The pistons will also almost certainly be down in the bores somewhat in a factory engine, which will affect the actual ratio vs. advertised.

[Classic1965]

Thanks for the response. I was going to do a compression test before I pulled the head to get the valves hardened.

[Wrenchbender Ret]

292 heads come with hardened valve seats even on the older models. They also have valve rotators on the exhaust valves.
I used to run them practically wide open for hundreds of miles in P30 step vans. They are a tough engine.

[66Submarine]

I don't think they came with hardened seats, and I've never seen anything that said they did, either. They did have the rotators, but I think that's the only difference.

FWIW, IME/IMO hardened valve seats are unnecessary. Countless thousands of miles have been run without them and continue to be, and automotive gasoline hasn't had lead in it in years. Unless the head actually needs work done to the seats I'd leave it alone; there's debate how much TEL (tetraethyl lead) in gasoline really helped, anyway. At best, people claim under extreme conditions it did a little something, but in normal use it's probably pretty much totally pointless. Lots of guys are running air-cooled airplanes on unleaded now with great success, and that's much, much more demanding.

[cg285]

they most likely had induction hardened seats. i almost always replace the exhaust seats on the older engines when doing a valve job and, unless requested otherwise, i normally install new valves. they are cheap enough and it makes a better job.

[hddoc]

Originally Posted by Classic1965

Thanks for the response. I was going to do a compression test before I pulled the head to get the valves hardened.

I have a 64 292 and did a compression test a few weeks ago. 150 lbs in all 6 cylinders FYI. Doc

[Classic1965]

I will be getting the valves hardened regardless because the truck has roled over once and it can't hurt it. Does anyone know what the name of the green the motor is painted is called?

[66Submarine]

They didn't say anything about them being hardened in any way, or that they were different from the other engines in the series, so I think they are just soft seats.

It won't hurt to do valve work, but IMO it would be kind of a waste of money right now if they don't need it. Why not run it until they need to be done and then just freshen up the whole engine? Unless you are planning for it to be a daily driver for years and rack up tens of thousands of miles you probably won't ever need to mess with it at all. You can determine if the rings and valves are still sealing up like they should with the leakdown test. If it checks out good I wouldn't waste time taking it apart and messing with it, but that's just me. Considering it's all still together and has a few miles on it I'd just run it until the rings got too worn for my liking and rebuild it. In a truck you don't drive everyday that might be decades!

I think most people say Detroit Diesel (GM) Alpine Green is a paint match. (That's what everyone seems to use, anyway.)

[Classic1965]

I just don't want to get stranded on the freeway in Toronto somewhere, that is why I thought a valve job would be worth while, but you what say makes sense. This would be smarter than what I was planning to do.

[66Submarine]

I get that, no one likes being stranded. I don't think you need to worry too much about being stranded with one of these with <200,000 on the clock though; look at this one I have!

This was my father's truck before he got his '66 and stopped driving it. Before that it was his DD, and he ran it for years; well over 100K miles. Never had ANY engine work in the time he owned it, and doesn't look to have had any for a very long time before that. I figure it probably has (at least!) 400,000+ miles going from wear (also it was totally shot when he bought it). After sitting for seven years I dusted the points off and it lit right back up! When his '66 was down he ran it for a few months, driving over 100 miles a day and eventually racking up another trouble-free 10K or so miles.

Also, it has at least seen the abuse of being boiled over from the water in the rad freezing, and being run at highway speeds in this condition and blowing most of the oil out.

After all that, the only thing it really does is burn (a lot of) oil! Still starts right up and goes down the road like it should. They really got the built-like-a-rock thing down when they designed these!

[66Submarine]

I forgot to mention that the blow-by/leakage from extreme ring wear also means the truck will roll down a very slight grade in first gear/reverse like the plugs are out! (That was actually a logistical problem when parking with no parking brake, as you can imagine... )

[Classic1965]

Wow I never knew these 292 engines were so tough. My truck has 105,067 miles on it. Sounds like it could go a lot further. My parking brake worked before I removed the body from the frame.

[66Submarine]

Wow, only 105K! That's got to be a nice truck. I wouldn't think twice about going anywhere in one with that low of mileage if it checks out good.

You should post a picture or two of the truck up.

[Classic1965]

The truck has a perfect frame still with factory paint, the body has been repainted multiple times and has lots of dents and bondo and enough rust to keep me busy. It's a southern truck so it's way better than the ones up here.

[Shaky]

Loves me some 292.

[TJ's Chevy]

I did a compression test on my 292 in my 66..95 pounds in all cylinders...runs really well for being so low in compression..that was a cold compression test though. The 292 is my 64 has about 120 pounds in all cylinders cold..and it sat for 14 years and after a dusting of the points it lit right off! The 292 is one heck of an engine I'll say! Specially when the one in my 66 will do 4800 rpm with stock internal components that have 147,000 miles and 48 yeas of wear!

[66Submarine]

BTW Shaky, I loved the CT to AK thread--thanks for posting that up! Great story with some really great pictures to go with it.

[Classic1965]

Nice post, I still have to do the compression test on the engine. Been working on other things and the truck is not getting the attention it deserves, but it will as soon as the boat is done.