Dumbo The Flying Elephant

[Larry Hill]

Got the honing plates on Dumbo with the crank still in the block to check cylinder straightness. Bottom line is we have to do something different, the cylinders were everywhere. .002 tight at 2-8 o’clock,10-4 slightly better, 12-6 loose tight loose, and 3-9 not bad.

I should have quit a little over a year after we started racing, because then I knew most of the answers!

[Glenn Briglio]

Originally Posted by Larry Hill

Got the honing plates on Dumbo with the crank still in the block to check cylinder straightness. Bottom line is we have to do something different, the cylinders were everywhere. .002 tight at 2-8 o’clock,10-4 slightly better, 12-6 loose tight loose, and 3-9 not bad.

I should have quit a little over a year after we started racing, because then I knew most of the answers!

Hey Larry, was the block sonic tested before using. The cylinder wall thickness is thin to begin with.

[Dyno]

I believe that Larry has the Mopar aluminum block. I have had friends that faced the same problems. You can try to hone it straight, but after you run it, the dimensions are all over the place. 8 Darton sleeves would be the place to begin or take a 100 lb weight penalty and use the cast iron BGE block.

[SSDiv6]

Originally Posted by Dyno

I believe that Larry has the Mopar aluminum block. I have had friends that faced the same problems. You can try to hone it straight, but after you run it, the dimensions are all over the place. 8 Darton sleeves would be the place to begin or take a 100 lb weight penalty and use the cast iron BGE block.

As Dyno stated, sleeve it.
The best is Steve Demirjian at Racing Engine Development in California.
He is also the Engine Shop Manager of Darton and one of the foremost experts in sleeving blocks holding many patents on engine sleeves.

http://www.raceenginedevelopment.com...odge-6-1-hemi/

[340Cuda]

Originally Posted by SSDiv6

As Dyno stated, sleeve it.
The best is Steve Demirjian at Racing Engine Development in California.
He is also the Engine Shop Manager of Darton and one of the foremost experts in sleeving blocks holding many patents on engine sleeves.

http://www.raceenginedevelopment.com...odge-6-1-hemi/

In my opinion another expert in sleeving and cylinder wall finish is Brad Lagman at QMP Racing.

Hidden Horsepower episode on cylinder honing.



However last time a checked and it is probably worse now, he had a thirteen week backlog on block work.

[Larry Hill]

It maybe a case of the block is not strong enough for the cylinder pressure generated under full load. My guess, and it’s only a guess, that the cylinders balloon and contract every cycle and become not straight and out of round in time.

For now I’m learning the do’s and don’t of the engine. With few parts available I’m doing my best not to destroy anything. I believe better sleeves will change things.

[Todd Gross]

Originally Posted by Dyno

I believe that Larry has the Mopar aluminum block. I have had friends that faced the same problems. You can try to hone it straight, but after you run it, the dimensions are all over the place. 8 Darton sleeves would be the place to begin or take a 100 lb weight penalty and use the cast iron BGE block.

Sorry to side track the thread, but is it legal to use the BGE in place of the MP Aluminum block? I did not see anything listed on NHRA accecpted products or 2015 Blueprint page regarding the BGE block.

[Larry Hill]

With me weighing 300+ the iron block would have to make a lot more power for me to consider it. If it not on the list I can’t use it. I try to walk on the knife edge on the rules, but I always have a set of gaskets and I am fearless going to the barn. Been doing this 30 some years and have been good every time, but all it takes is one third of the thickness of a hair (.001”) on the wrong side of a number and I will be disqualified.

[Larry Hill]

With the block having 16 main studs and location sleeves for the caps removing the caps quickly use to be difficult. Solution was a Gen III cap puller from Arrow. It’s great

[Stan Weiss]

Originally Posted by Larry Hill

With me weighing 300+ the iron block would have to make a lot more power for me to consider it. If it not on the list I can’t use it. I try to walk on the knife edge on the rules, but I always have a set of gaskets and I am fearless going to the barn. Been doing this 30 some years and have been good every time, but all it takes is one third of the thickness of a hair (.001”) on the wrong side of a number and I will be disqualified.

Larry,
If your weight and the car's weight does not change then all the iron block has to do is make enough HP to offset the difference in the weight between the 2 blocks. I do not know what the difference will be for those blocks. I do know that many years ago on a difference style engine / block making about 750 HP the iron block made about 15 more HP.

Stan