Richard Holdener to test the Piston Reversal theory

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rumblefish360 said:
True..... But!!!....
What kind of “Class” in racing would require stock pistons? Ether today or yesteryear?
As mentioned above.... the super right on budget would seem these kinds of tips and tricks.
In my head, if I had to run a stock piston & bore size, then the cams I’m looking at are low lift.... stock-super stock class type cams I think. Long duration and stock lobe lift.

True for the “LA” engine, not so much for a Magnum engine, mileage dependent maybe? IDK!

All in all, a good used core is going to be a Magnum IMO and I think you could build quite a runner with the base long block.
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Those low lift, long duration cams are even more problematic, its more the duration that gets you in trouble with piston to valve clearance rather than actual lift in my experience.
 
True... true.... radical idle @1,000+ rpm acting belligerent.
 
TT5.9mag said:
For what it’s worth my junkyard magnum when torn down showed very little measurable bore wear or taper at 91,300 verified miles. Rod bearings showed a little scuffing, main and cam bearings looked brand new. Measured factory ring gap on all 8 top rings and all were 020-024.
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Magnums really do well when tearing them down. Many 100k motors still show cross hatching. Must be some hard iron.
 
Hell, Richard ain't got a need to do the experiment. We'll have it hashed out right here before he ever gets a chance.
 
440 6 pack pistons have 4 valve reliefs. Hmmm... I wonder what the factory was thinking?
 
pishta said:
Magnums really do well when tearing them down. Many 100k motors still show cross hatching. Must be some hard iron.
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Good iron, good factory machining, well made factory internal parts with tight tolerances, fuel injection, modern ring pack, and most importantly an owner that cares about his vehicle. I got to drive the truck it came out of. Wrecked in the rear and totaled. The interior was spotless and the only wear was in the driver seat. I could tell the owner was diligent about caring for his/her vehicle.
 
Those are the ones to hunt in the bone yards, totaled vehicles that were taken off the road for other than drive train reasons.
 
TT5.9mag said:
Good iron, good factory machining, well made factory internal parts with tight tolerances, fuel injection, modern ring pack, and most importantly an owner that cares about his vehicle. I got to drive the truck it came out of. Wrecked in the rear and totaled. The interior was spotless and the only wear was in the driver seat. I could tell the owner was diligent about caring for his/her vehicle.
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My 01 van has 215,000 use no oil, no ridge, clean inside (had to fix that intake) leaking around one valve cover so I guess I’ll get a gasket. I have another block that’s sludged up bad (bad crank) but no ridge, I’m saying the rings
 
The 318 I found rebuilt 20 years ago in an ecology... i went through with my friend John's advice and flipped the rod/pistons bank to bank to reverse them. I remember one needed pressed a hair more..so I took it to smokies speed m machine and he let barrow the press 'i didn't have one back then'. Motor ran good is all I can say. No big dollar dyno testing of it.
.020 over ,340 cam, 324 heads, performer intake and eddy 600, headers 2 1/2 pipes 4 spd 3.91
Same motor that had the relief spring stick on me.
 
I usually don’t chime in on these debates and I don’t claim to be anything more then a shade-tree DIY’er. I haven’t seen anyone use this analogy (that I described below) to explain why reversing the pistons could add ‘something’ to the motor. This analogy is exaggerated, but it makes it easier to understand.
Compare it to using your 18” HF breaker bar to loosen lug nuts... Put the socket on a lug nut so the bar is clocked to the
11:30 position (looking at the wheel like a clock). Then attempt to break the lug nut loose by pushing straight down, (straight down in the key here) perpendicular to the ground on the handle. Your force is not being affectively applied in the arrangement, most of it is traveling straight down (through) the handle because the angle is so slight.
Now re-clock the bar on the lugnut to 9 o’clock and push straight down on the handle. In the arrangement you are applying the force at a 90° angle making the most use of the level effect.
Same idea with the piston/rod alignment. Reversing the offset give the rod some lead into more angle on the crank when peak combustion/work is being applied from the flame.
I think Richard will need to start the pull as low as possible to see the effect. I think the torque curve will see maybe 10lbs better in the 2,000-3,500 range and then be no different at the top end. Once everything is moving 5 or 6,000 that lead is going to be negligible.
This is why Tony’s says your more likely to feel it in a car and not see it on a graph…
Just my 3 cents…
 
I'm betting you may run into small issues swapping factory C pistons into a EE bore and getting that EE piston into the C bore. Just saying you may end up with a lot of skirt slop on one and too tight the other way.
 
HotRod777 said:
I usually don’t chime in on these debates and I don’t claim to be anything more then a shade-tree DIY’er. I haven’t seen anyone use this analogy (that I described below) to explain why reversing the pistons could add ‘something’ to the motor. This analogy is exaggerated, but it makes it easier to understand.
Compare it to using your 18” HF breaker bar to loosen lug nuts... Put the socket on a lug nut so the bar is clocked to the
11:30 position (looking at the wheel like a clock). Then attempt to break the lug nut loose by pushing straight down, (straight down in the key here) perpendicular to the ground on the handle. Your force is not being affectively applied in the arrangement, most of it is traveling straight down (through) the handle because the angle is so slight.
Now re-clock the bar on the lugnut to 9 o’clock and push straight down on the handle. In the arrangement you are applying the force at a 90° angle making the most use of the level effect.
Same idea with the piston/rod alignment. Reversing the offset give the rod some lead into more angle on the crank when peak combustion/work is being applied from the flame.
I think Richard will need to start the pull as low as possible to see the effect. I think the torque curve will see maybe 10lbs better in the 2,000-3,500 range and then be no different at the top end. Once everything is moving 5 or 6,000 that lead is going to be negligible.
This is why Tony’s says your more likely to feel it in a car and not see it on a graph…
Just my 3 cents…
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A similar story I recall (from Smokey Yunick's Power Secrets book, I think) is that he noticed when assembling an engine, that if the piston pin was centered, no amount of air pressure through the plug hole would push the piston down. Offset, it would go easily. He said that had to be better, less work against itself, and from then on, he specified offset pins when ordering pistons ( I assume reverse direction from stock/OE).
 
kowalski440 said:
A similar story I recall (from Smokey Yunick's Power Secrets book, I think) is that he noticed when assembling an engine, that if the piston pin was centered, no amount of air pressure through the plug hole would push the piston down. Offset, it would go easily. He said that had to be better, less work against itself, and from then on, he specified offset pins when ordering pistons ( I assume reverse direction from stock/OE).
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i was told assumption is the mother of all **** ups :rofl:
 
kowalski440 said:
A similar story I recall (from Smokey Yunick's Power Secrets book, I think) is that he noticed when assembling an engine, that if the piston pin was centered, no amount of air pressure through the plug hole would push the piston down. Offset, it would go easily. He said that had to be better, less work against itself, and from then on, he specified offset pins when ordering pistons ( I assume reverse direction from stock/OE).
Click to expand...
No assumptions, it will be offset in direction to turn crank forward. It’s like getting a head start on turning
 
Yamaha has been off setting the whole cylinder bore over the crank for years now. Piston, when at TDC, the crank is already at like 15 degree ATDC
 
It's funny how modern engines last a long time because of machining and materials and blah blah blah but not once is oil mentioned. The oil of today is 1 billion times ahead of the oil of 1965. Oil, and EFI. Machining and materials are way back in the pack.
 
Today’s machining and materials are much nicer. But even in the early days of machining they could get things to fit amazingly well. The biggest advancement for engines was the aluminum/copper piston.

Oil certainly has come a long way as well as EFI. Nothing like cracking open a Magnum w/80K plus and seeing crosshatching.
 
I have built NUMEROUS chevy LS engines, where you couldn't determine any bore wear, run a hone through it, new pistons and good to go.
 
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