Blown Engine

I not sure you can have to much compression. Maybe it was not enough octang in the fuel or to much timing.

Mark,
I've always run it on premium which as you know is only 91 octane out here. Unless something has moved, the timing should still be set at 34 degrees total. I never could hear any pinging which I think would be consistant with detonation or a lean condition?

quote:

Originally posted by Mark Mensen:
I not sure you can have to much compression. Maybe it was not enough octang in the fuel or to much timing.

What did your exhaust pipe tips look like inside? Black, White? Maybe you were running lean?

Also wondering if you have pulled a valve cover yet? When I had blown the motor on the blue car, the valve head had snapped off and put a hole in the piston

Sorry to hear of your troubles.

Art,

From what you explained the Tech session in Vegas and your post on the DT e-mail list with a disintegrated spark plug I think it has to be more than just running lean or too much compression, more like something mechanical failed. You drove it all the way to Vegas right (I heard pretty fast too ) and any problem of the lean nature one would have expected to surface on extended driving runs.

Good luck and let us know when you strip it down.

Julian

I also cracked my drivers side cylinder head on the trip to and from Vegas. I think anything that is marginal on our cars will surface when we push them hard. We threw my head in the trash. Hopefully your damage was minimal. Good luck too!!

I don't ever remember the exhaust tips looking anything but black. The engine has always used a lot of oil, so even if it was running lean, I don't know if I could tell by looking at the tips?

quote:

Originally posted by Rapid:
What did your exhaust pipe tips look like inside? Black, White? Maybe you were running lean?

What makes me think I may have too much compression as opposed to being lean is that my problems have all been in the right bank, #'s 1,2,3 and 4. I can understand having more compression on one side than the other. I haven't heard much of an explanation as to how I could be lean on one side and not the other? I am by the way running a carb.

I did start by pulling my right valve cover and could see no obvious problem. Then we pulled the plugs and saw very bad things.

quote:

Originally posted by Rapid:
Also wondering if you have pulled a valve cover yet? When I had blown the motor on the blue car, the valve head had snapped off and put a hole in the piston

Art, Sorry to hear of your engine woes. You asked on the Detomaso mailing list about the new cleveland blocks being cast in iron and aluminum and I havent noticed any responce to that yet. Is there anyone here who can supply an update or a link to that info? This is where I heard about it in the recent past. best regards, Jim Coyne

quote:

I haven't heard much of an explanation as to how I could be lean on one side and not the other? I am by the way running a carb.

Are you running a dual plane or single plane manifold? A dual plane without any equalizing notch/cut out and a carb problem/blocked jets I guess could permit a lean on one bank scenario.

How many miles were there on this engine?

Julian

Thank you Jim. Will Demelo on the other list posted a link to the 335 Cleveland forum where I found the info on the new blocks.

Art

quote:

Originally posted by tecnosound:
Art, Sorry to hear of your engine woes. You asked on the Detomaso mailing list about the new cleveland blocks being cast in iron and aluminum and I havent noticed any responce to that yet. Is there anyone here who can supply an update or a link to that info? This is where I heard about it in the recent past. best regards, Jim Coyne

Julian,
I'm running the Blue Thunder dual plane with an equalizing notch. The engine has about 13,000 miles on it. Even with the notch in the manifold, I guess it could be a carb problem? A way to check that would probably be to put the car on the dyno, and stick the sniffer in one side and then the other? When I had the car on the dyno, it was not lean, but the sniffer only went into the left side and not the right. The right side being the problem side.
Thanks,

Art

quote:

Are you running a dual plane or single plane manifold? A dual plane without any equalizing notch/cut out and a carb problem/blocked jets I guess could permit a lean on one bank scenario.

How many miles were there on this engine?

Julian[/QUOTE]

quote:

Originally posted by tecnosound:
...new cleveland blocks being cast in iron and aluminum ...Is there anyone here who can supply an update or a link to that info...

The info is posted here as timely as it is posted on the Cleveland forum.

http://pantera.infopop.cc/eve/forums/a/tpc/f/8250045562/m/6130089184

there is no new "news" since this post. the last word was Tod was going to a financer to fund the project. He's ready to cast the first experimental blocks. those will be delivered to select engine builders to assemble for their feedback about any changes that may need to be made.

I'll keep you posted about any further developments as I am notified.

cowboy from hell

Thank you George. An aluminum Cleveland block sure sounds like a winner to me.

Art

Art,
Until you get into the tear down will you really know for sure what happened to the internals. So why wait, start throwing wrenches and pull it...

One other area to inspect is the muffler on that bank of cylinders. Just make sure nothing is creating a restriction.

It doesn't matter whether your manifold is single or dual plane in this case. Two cylinders in each bank are fed by the opposite side carb venturi on dual plane and all cylinders feed from a common plenum on a single plane. If you had a problem with the center two cylinders on one side and the outer two on the other then it well could be a carb issue. You need to get it torn down to determine what went wrong. Check deck heights on each side after you pull the heads.
Forest

Forestg
Not to get off topic but when is the artichoke festival?

Miles

My exhaust bracket on the right side did break on the trip. That allowed the exhaust pipe to ride on the sway bar, slightly denting the pipe. I doubt that this caused the problem because I have had problems on the right side before. But it probably didn't help matters any?
Thanks Steve,

Art


Steve

quote:

Originally posted by ROVERLTD:

One other area to inspect is the muffler on that bank of cylinders. Just make sure nothing is creating a restriction.

Forest,
How do I check the deck heights?
Thanks,

Art

quote:

Originally posted by forestg:
It doesn't matter whether your manifold is single or dual plane in this case. Two cylinders in each bank are fed by the opposite side carb venturi on dual plane and all cylinders feed from a common plenum on a single plane. If you had a problem with the center two cylinders on one side and the outer two on the other then it well could be a carb issue. You need to get it torn down to determine what went wrong. Check deck heights on each side after you pull the heads.
Forest

An interesting side note. After buying the heads, I had them CC'd. The numbers I wrote down are 62.5 and 66.6, maybe that is where the problem lies? It appears to me that one of those heads would make for higher compression than the other? It seems that this could explain my problem? What do you guys think?

Art

[QUOTE]Originally posted by Art Stephens:
Forest,
How do I check the deck heights?
Thanks,

Art

You can get an approximation with a feeler gauge when the heads are off and a piston is at TDC.
Most of the Cleveland pistons I have seen have a flat, square edge at some point on them.

You are trying to determine how far down in the hole the piston is at TDC. In an ideal world it would be .000". Probably .010" would be ideal.

Apparently the Clevelands vary from year to year but it could be as much as .050". That's what I would expect to find.

It can also vary from the front of the block to the rear, so you should at least check front to back if not every cylinder.

quote:

Originally posted by Art Stephens:
...After buying the heads, I had them CC'd. The numbers I wrote down are 62.5 and 66.6, maybe that is where the problem lies? It appears to me that one of those heads would make for higher compression than the other? It seems that this could explain my problem? What do you guys think?

Art, the 62.5 cc head is a 1970 vintage D0AE casting, the 66.6 cc head is a 1971 vintage D1AE casting. 1970 Clevelands were nominal 10.0:1 compression (11.0:1 advertised), 1971 Clevelands were nominal 9.7:1 compression (10.7:1 advertised).

Doug, to zero deck a Clevo, the nominal material to remove is 0.030", except for the 1972 H.O. motor, which had fordged pistons with a different pin height, the piston rode slightly higher than the piston in any other Clevo.

cowboy from hell

How many cc's is .030"? Haven't built one in a couple x couple of yarn.
The A3's were 60cc's as I recall. Thats I remembers.

When decking a block with a standard 4.000" bore: 1 cc per 0.005” removed from the block. An average zero decked block (standard bore) subtract 5 cc to 7 cc (0.025" to 0.035").

cowboy fom hell

Art,
A small dent in the exhaust pipe would not matter. You are looking for something really bad like the internals of the muffler broken loose and jaming up the works or a major kink (1/3 to 1/2 of the pipe nicked down). The pipes will have to come off when tugging out the engine so worth a check. Rare occurance these days with better assembly processes of mufflers but possible.