Freshening up my A headed 526ci

The oil pressure was acting funny so We pulled the motor apart and found a crack. The motor needed to be freshen up anywas. It was getting to much oil to the top. This block doesn't owe us anything. It's been around forever. I also broke the trans.









So we had a Dove block and we machined it for the replacement. We also had another set of pistons for the A heads that will bump the compression up a tad to 15.46:1.

how much time / passes where on the block?

dfree383 wrote:how much time / passes where on the block?

I would say the block has around 6,000 runs on it. It's been a race block for 20 years. On this set up I have 402 runs on it.

Boy it looks like you got lucky and caught it in time before it got real nasty. Good luck on the new engine faster is always nice.

Yea I got real lucky.

Which main is that ?

Number 2

BigBlockFalcon wrote:Number 2

Seems that's most always the case.

Yea I was going to tell you to guess. Yea that's seem like the one that lets go.

Thanks for the input. Being that the #2 main is the most likey to fail it would suggest that going to the 351W or Flat head firing order would be a better deal in a very high horsepower engine.

On our C headed motor we run a flat head firing order. I will look into doing a firing order swap in the future. Number 2 and 6 firing right after each other puts a pounding on that main.

BigBlockFalcon wrote:I would say the block has around 6,000 runs on it. It's been a race block for 20 years. On this set up I have 402 runs on it.

If you are serious about the 6000 passes on the block throughout its build history then that is quite a feat.  Good thing you pulled it down when oil pressure started acting funny.

I cannot make out what this picture is, please explain what we are looking at here (trans?):




Also, which type of main fasteners were used? And you said the transmission broke at the samed time--what happened there?

Paul

Over the history of that block it probably an honest 4000 runs. I'm using factory main cap bolts. Yes the picture is the trans where the shift linkage and band adjuster is. I wouldn't say they both broke at the sametime. It just happened that way. The last past when I saw the oil pressure acting funny it went 5.13@133. When i got back to the pits we looked thngs over and seen a puddle of trans fluid. The trans pressure relief valve stuck and built up pressure and cracked the case. New case and I'm ready to pick it up tomorrow.

Makes you wonder if a good 4 bolt cap would have spread the load more evenly across and out to the pan rail and eased the loading on the number two main bolts and webbing some.

IDT-572 wrote:Makes you wonder if a good 4 bolt cap would have spread the load more evenly across and out to the pan rail and eased the loading on the number two main bolts and webbing some.

That is the case....and is the value of a four bolt cap.

Putting grade 18 bolt/stud or whatever in a two bolt cap application and jacking the tq. up to 155 lbs. ft. or whatever just loads a small area of the block more.

Lem Evans wrote:Thanks for the input. Being that the #2 main is the most likey to fail it would suggest that going to the 351W or Flat head firing order would be a better deal in a very high horsepower engine.

would'nt it be the same with #3 and #7 having a 351w firing order?

BigBlockFalcon wrote:Over the history of that block it probably an honest 4000 runs. I'm using factory main cap bolts. The last past when I saw the oil pressure acting funny it went 5.13@133.

Wow, 5.13 @ 133 mph in a door slammer.  I'm guessing you had between 900-1000 bhp in that engine.  Too bad the block finally broke but 20 years of racing with it is nothing to sneeze at, especially at the power levels you brought it up to. New build is looking good.

Paul

Lem Evans wrote:Thanks for the input. Being that the #2 main is the most likey to fail it would suggest that going to the 351W or Flat head firing order would be a better deal in a very high horsepower engine.

Lem is this common to do?

what fuel you running in that? or did you run on those pistons? are they the ones out of the other engine?

I ran Sunoco 116 with the other piston. These are different pistons and will run the same fuel.

The texture on the one picture looks like it was detonating slightly or is it just the picture?

I know my motor started detonating towards the end of its life. It was getting more oil up top then should of been there. These piston that are going in my motor now were in a motor 10 years ago. I think its just the picture

68formalGT wrote:

Lem Evans wrote:Thanks for the input. Being that the #2 main is the most likey to fail it would suggest that going to the 351W or Flat head firing order would be a better deal in a very high horsepower engine.

Lem is this common to do?

It is common to do the alternative firing orders on engines with very high hp & very long strokes. I am not a proponet of guys with 521" pump gas engines buying a new cam.

If I were doing a 1,000-1,300 hp engine plus putting the 'hose' to it like a T/S of T/D deal....the flat head firing order would be part of the package.

BigBlockFalcon wrote:I know my motor started detonating towards the end of its life...

I would say that the detonation is a factor in the cylinder block's demise (and the fact that it ran for 20 years supports this). Had the engine been kept out of detonation, the cylinder block very well might have stayed together. Nevertheless, it's served well all these years.

Paul