5 main, chev, crankModel A engine

[Herb Kephart]

George

VERY interested in this--and have a couple questions.
You moved the main bearing stud centers out to an area where the rib in the block is thin--what did you do about this? Also what do you intend to do about the misalignment of the lifter holes with the respective cam lobe?
Also, I wonder why you bored the big end of the rods on your lathe? I always did it in the mill, to insure parallelism of the hole, with the just bored wrist pin hole--neglecting inevitable table rock.
Wondering also if you did the line boring your self? I have line bored the mains on both Ford and Chevy fours on the Bridgeport with a truly Mickey Mouse rig--but the reground crank spins in the inset bearings--so I was happy. The table is longer than your Moog, admit ably. Looked for a photo of this, but I guess that it was on film, and now is lost in a one of many boxes.

Herb Kephart

 

[George Miller]

What Chevy engine are the crank and cam out of?

Charlie Stephens

Big journal 327. the stroke is only 3.250. But I,m not after torque. More rpms and HP will work for me.

 

[George Miller]

Also, I wonder why you bored the big end of the rods on your lathe?

To me it is easier faster, no tapper when bored, more rigid, so no chatter.

I always did it in the mill, to insure parallelism of the hole, with the just bored wrist pin hole

The fixture on the lathe makes sure it has no twist. parallels between face plate and part make sure it is square. Then you can check it with a indicator for final check.

Wondering also if you did the line boring your self?

Yes made my own machine. use on the mill with a right angle head.

I have made 3 sets of 7075 rods before for the A crank for different kinds of pistons. They worked real well.

 

[George Miller]

Hey George,
Wow, 'never' worked or seen B ! I'd have lost $ betting against that .
BTW..When you get time to add notes/information (tutorial) on how you add the extra two mains to a stock block !

Punch my name go to my album. hit show all albums. There is a picture there of the 5 main with out a crank, that show what you want to know.

 

[George Miller]

George

VERY interested in this--and have a couple questions.
You moved the main bearing stud centers out to an area where the rib in the block is thin--what did you do about this? Also what do you intend to do about the misalignment of the lifter holes with the respective cam lobe?
Also, I wonder why you bored the big end of the rods on your lathe? I always did it in the mill, to insure parallelism of the hole, with the just bored wrist pin hole--neglecting inevitable table rock.
Wondering also if you did the line boring your self? I have line bored the mains on both Ford and Chevy fours on the Bridgeport with a truly Mickey Mouse rig--but the reground crank spins in the inset bearings--so I was happy. The table is longer than your Moog, admit ably. Looked for a photo of this, but I guess that it was on film, and now is lost in a one of many boxes.

Herb Kephart

The miss alinement of lifter bores will be fixed with new lifter boss made in one long bar. Then attached to the block.

 

[hardtimes]

Punch my name go to my album. hit show all albums. There is a picture there of the 5 main with out a crank, that show what you want to know.

Thanks George ! Keep up your interesting/innovative work,eh !!

 

[Bob Bidonde]

George,
Your cerebral and machine skills are fantastic.

 

[holdover]

Now that is engineering, and innovation.

 

[George Miller]

Squaring up the end of rod,cap and drill holes to hold cap on.

Next will be putting the rotary table on the mill to shape the rods. Then finish bore.

 

[George Miller]

Rough boring crank pin end. Now the rod will get shaped then come back for finish bore. It needs be rough bored first because when you relive all that metal it will distort some. Then when you come back and finish bore it will stay round.

Also a picture of drilling the holes for the rod cap.

 

[George Miller]

Putting on the radius on the big end of rod.

Still more work. Need to do the finish bore, and more shaping on the rod.
Maybe next week.

 

[hardtimes]

Putting on the radius on the big end of rod.

Still more work. Need to do the finish bore, and more shaping on the rod.
Maybe next week.

Hey George,
Nice work, also thanks for pictures !
I curious, since you indicate that you are after/will get more RPMs with this engine....how do aluminum rods rate (for wear/durability) against steel rods ? Ok, less weight, but what about stretch and deforming, etc ?
I contemplated using alum rods , for recipro wt savings, but settled for Crower. I've often wondered whether there are better /best alum rods ?

 

[George Miller]

Well I'm not sure how much weight you would save, depending on what kind of steel. You would have to make the alum bigger to have the same strength. 7075 is about 70,000 for tensile strength. If I was racing I would want steel like 4340.

Like most metals there are lots of grades and types of steel and alum.

 

[George Miller]

up date on rods. Shaped but still need to remove weight. They are heaver than stock chev rods.

 

[George Miller]

Well the rods are almost done. Just have to put in the notch for the bearing tank.

 

[Ron W]

The rods look very nice! How does the weight compare to stock? Ron W

 

[hale1776]

Reminds me of the Donovon Engine also 5 Main bearings http://www.modelaparts.net/hiperf.html/donovansem.html

 

[George Miller]

The rods look very nice! How does the weight compare to stock? Ron W

They are about the same weight. But they are also about 2 inches longer than stock chev rods. I think 7075 is heaver than lesser strength Alum.

 

[johnneilson]

George,

7075T6 is much stronger than 6061T6 tensile and yield. on the order of 1.6~1.8 x

 

[hardtimes]

Well the rods are almost done. Just have to put in the notch for the bearing tank.

Hey George,
Wow, nice product ! Do you know expansion/grow rate of these rods , compared to Ford rods ? What bolts/nuts (chev?) are you using to fasten rod caps ?