455 Engine question

[Fred Rawling]

This is a 1972 Electra with 108,500 miles on it.   Igot it hot 10 years ago and bkew a head gasket.  t has sat from then.

 

I WANT SOME OPINIONS OR ADVICE.

 

I have the heads off.  The valves and seats look pretty good so I am thinking of laping then in and having a clean up cut on the surface of the head.

 

Should I do the rings?  I should have measured  the bore taper before I asked that question.  There is a ridge on the cylinders.

 

Fred Rawling

 

 

 

[avgwarhawk]

If the ridge on the cylinder is catching a finger nail I would look to have the block machined and rebuild the engine.  If the ridge is not much of anything maybe hone and new rings.  You should install a new timing chain and gears as well.   

[Ben Bruce aka First Born]

Technically, I expect Chris is correct.  BUT!  Do you expect to drive it a lot? Or just a thousand or so a year?  When these cars were just used cars, we often/always reamed the ridge out, installed new rings and drove them. When they were the only thing we had. 

 As to the overheat, that would convince me to pull the pistons and inspect. Alum pistons do gaul [sp] from too much heat.  If they, the pistons look ok, I would re ring , new bearings and go.  

 

  Ben

[Fred Rawling]

Thaks to both of you.  I am going to drive it for my everyday car.

 

I was thinking that I would have to do the rings.  On the other 2 cars that I had, around 100,000 the engine was getting tired.  I appreciate the reminder on the timing chain also.  I was not thinking of that.

 

I bought a 1973 Pontiac Boniville new.  The next one was a 1973 Caprice.  This Buick is the basically the same car with a couple if dash switches in a different place. I like the car. It is a 4 door hard top.  The seats fit my but, it rides nice,  I can cherp the tires from the stop sign and I can work on it without and engineerng degree .

 

Thanks again.

 

Fred

[NTX5467]

I'd vote for the ring and bearing route, personally.  Do get the heads surfaced (mill-cut is usually better than the "rotating rock" surfacing).  PLUS a new Cloyes double-roller timing chain!  OEM-level rings and bearings, ONLY.

 

I found some Castrol black bottle 5W-30 syn oil at Walmart a while back.  This one is different as it is "SL"rated, which is supposed to be the newest rating which has about 1000ppm of zddp in it for good camshaft life.  NO "Dexoa Approved" logos anywhere, either.

 

Usually, from what I've seen, pistons will not "gaul" if they have good lubrication on the skirts (from splash or "fog" oil mist).  IF you find that, it's re-bore and new piston time, usually.  Although some file work on the skirts to smooth them back out might be a shade-tree short-cut, followed by a quick dingleberry hone job.

 

Just some thoughts,

NTX5467

[Fred Rawling]

I was thinking of synthetic oil.  Is draining the pan enough or do I have to remove it and clean it?

 

I had 2 valves with a 3/16 inch crack in the edge. 

 

The guy at the machine shop said that the valve seats looked real good and suggested that I wear them out before changing them.

 

When I removed a water pump bolt and saw the anti seize that I put on them,   I looked through my file on the car and found that I had changed the timing chain.

 

ANY SUGGESTIONS ON WHAT I COULD DO TO GET BETTER THAN 10 MPG?

 

[Fred Rawling]

FORTUNATLY IT IS SMOG CHECK EXEMPT

[Ben Bruce aka First Born]

7 hours ago, Fred Rawling said:

I was thinking of synthetic oil.  Is draining the pan enough or do I have to remove it and cl

 

ANY SUGGESTIONS ON WHAT I COULD DO TO GET BETTER THAN 10 MPG?

  That is BAD!  

       Not too popular on here, but I went EFI on my 1950.  Also installed higher speed gears.

 

  Ben

7 hours ago, Fred Rawling said:

 

 

[old-tank]

10 hours ago, Fred Rawling said:

ANY SUGGESTIONS ON WHAT I COULD DO TO GET BETTER THAN 10 MPG?

That is about right if town driving...or 85-90 mph on Texas interstates.  Should be 14-16 mpg at 70 mph freeway trips.  Start by checking ignition, especially vacuum and centrifugal advance and base timing.

[NTX5467]

Not sure what went haywire with the 455s compared to the 430s that came before them (which would get approx 20mph on road trips, according to posts in here a good while back), but something did!  Was it the lower compression ratio by itself?  "Retarded" emissions-tune ignition timing?  Retarded cam sprocket timing?  Seems like that most road tests of the 455s in Electras and such did good to get to 14mph on a trip?

 

BUT . . . before you start messing with it, once everything's back together, fill the tank and head out on a 100 mile Interstate cruise on "flat lands" with the cruise control in use.  70mph from and back to the same gas station and gas pump.  While on the road, use the mile markers to calibrate the odometer, too, IF your phone does not have a GPS speed/distance function on it.  Please let us know how this trip works out.  MPH, mpg, and such.  It might ride a bit rougher, but set the tire pressures to 32frt/30rr when "cold" before the car is driven.

 

Going to throttle body EFI as Ben did CAN increase fuel economy, but it is NOT a magic bullet on some cars, by observation.

 

You might be getting 10mpg in your daily driving (stop/go/cruise), but it's best to get a handle on highway cruise economy FIRST.  As that is with the engine fully warm, at an efficient rpm level, etc.  Once THAT is determined and optimized, THEN worry about the other stuff (which also might include some tips about driving techniques/orientations).

 

Keep us posted as to your progress,

NTX54667

 

Edited March 25, 2022 by NTX5467 (see edit history)

[Fred Rawling]

This has been going slower than  hoped for.

 

I got the heads on and found that I had not bought exhaust manifild gaskets which had to be ordered.

 

I see that the rocker arms have worn about 1/32 grove in the shaft. All the after market shop manuels do not say anything about what the maximum wear allowed would be.  What thoughts do any of you have?  I am going by the machine shop Monday to see if they know anything about it.

 

I was thinking about EFI but I need to get it running first.  

[Fred Rawling]

Reading the thred on carbs vs injection, I am wondering if I should have the carb rebuilt?

[old-tank]

http://www.rockerarms.com

 

[carbking]

If it got hot, rings and bearings for certain.

 

If it is a daily driver, I would do a complete rebuild with boring the cylinders and pistons, as well as the rings and bearings.

 

As to the fuel economy???

 

Dad bought a 1972 225 new in 1972; trading in a 70 Mercury. The Buick wouldn't run with the Merc; but the 14 MPG of the Merc went to 17 MPG with the Buick (highway 70 MPH). It wasn't driven around town, so I have no idea what to expect with city driving. But 10 MPG highway simply means something is BAD WRONG! 

 

I would suggest trying to determine the issue before throwing different parts at it.

 

Jon

[carbking]

Thinking about that fuel mileage:

 

Tire pressures?

Dragging brake?

Partially clogged mufflers?

Bug screen on the hood? (No joke, Dad bought a used Ford F100 with one of these, removing the bug screen ALONE improved fuel economy by almost 25 percent!)

 

All fuel economy is not the fault of the engine.

 

Jon.

[avgwarhawk]

I owned a 73 Estate wagon.  If one  purchases an Estate wagon gas mileage was not a concern.  The wagon averaged 15 miles per gallon.  Then again, I was and still am a lead foot. I did take my wagon to 75-80 Dragway for a bit of bracket racing. Call me crazy.  One fine afternoon the wagon made a Baltimore MD to Washington DC in 30 minutes flat.  I miss that 9 passenger Porsche.