I have unfortunately lost a wrist pin for my Venolia pistons in my small block Chrysler. Because of this I have decided to replace the entire set. The pins that I have currently are 0.927" x 2.850" x 0.090" wall. The I have changed the stroke since the engine was last run (Increased from 3.6"-4.0"), and thus brought the compression up by just under 2 points, it's a tad under 13:1 now. The engine was a pump gas engine, but will now be run on methanol, or at worse, a race gas.
I can get an exact set from Childs&Albert to replace them, but have been thinking about going with a thicker walled taper wall pin instead. Any thoughts on the subject?
Thanks
AL...
Which Wrist pins?
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OldSStroker
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Those are pretty light pins, about 86 gms as you described them. Is the rest of the system light weight? Piston wt = ?
The rotating assembly has not been balanced yet, I assume.
How fast will you turn it? How much HP do you plan to make?
Is it an endurance engine, or a 10 sec. drag engine?
NA or nitrous? How much?
If you bought the pins with the pistons for the stroker, the pins should have been spec'd for the engine's use.
The rotating assembly has not been balanced yet, I assume.
How fast will you turn it? How much HP do you plan to make?
Is it an endurance engine, or a 10 sec. drag engine?
NA or nitrous? How much?
If you bought the pins with the pistons for the stroker, the pins should have been spec'd for the engine's use.
Re: Which Wrist pins?
I would go much thicker especially if you already ate a wrist pin. Like Oldsstroker said look at what you have and look at weight and rpm and intended usage and if you aren't building a comp eliminator engine and maybe even then just use a pin you KNOW will stand up to what you are dealing it. Even with tool steel a .090 wall pin is pretty weak. You can probably go up to a .120 wall tool steel or a regular .150 wall pin and solve a lot of your problems for cheap. Is there a lot of unsupported pin hanging out there as in a wide pin boss spacing and a narrow top end width of the rod? Then it will be even worse with a thin wall pin plus you will have to run a lot of clearance to keep stuff from contacting when the piston and pin are flexing. I would go up on the wall thickness no matter what.la360 wrote:I have unfortunately lost a wrist pin for my Venolia pistons in my small block Chrysler. Because of this I have decided to replace the entire set. The pins that I have currently are 0.927" x 2.850" x 0.090" wall. The I have changed the stroke since the engine was last run (Increased from 3.6"-4.0"), and thus brought the compression up by just under 2 points, it's a tad under 13:1 now. The engine was a pump gas engine, but will now be run on methanol, or at worse, a race gas.
I can get an exact set from Childs&Albert to replace them, but have been thinking about going with a thicker walled taper wall pin instead. Any thoughts on the subject?
Thanks
AL...
Erik Koenig
Houston, TX
http://samracing.com
http://HKRacingEngines.com
Houston, TX
http://samracing.com
http://HKRacingEngines.com
The piston weighs 400 grams, it's a gas ported Venolia flat top piston. It was running a BME Alluminium rod, which are being replaced with a shorter MGP or GRP rod, so the rotating assembly is reasonably light.
The small end on the current rods are quite wide, and I will most likefully have the new rods made in the same manner.
I actually misplaced one of the wrist pins, I am not replacing them because they were damaged. They actually measure up quite well, only showing a couple of tenths of wear from what I recall. It has been a little while since I miced them.
As for the rest of the engine, It was a 365 cube engine, and I will be increasing the stroke to provide 406 cubes. I would like to keep the revs under 7000-7200 rpm.
I was thinking about going to a thicker walled pin, as I would most likefully end up with a lighter rod, the BME rods the engine had when it was a 365 cuber weighed over 600 grams, it was one of their 396 forgings.
Should I go taper wall, or straight wall? It will basically be a normally aspirated Methanol engine, revs will be just over the 7000 range, if that high at all.
I hope I answered everything
Thanks
AL....
The small end on the current rods are quite wide, and I will most likefully have the new rods made in the same manner.
I actually misplaced one of the wrist pins, I am not replacing them because they were damaged. They actually measure up quite well, only showing a couple of tenths of wear from what I recall. It has been a little while since I miced them.
As for the rest of the engine, It was a 365 cube engine, and I will be increasing the stroke to provide 406 cubes. I would like to keep the revs under 7000-7200 rpm.
I was thinking about going to a thicker walled pin, as I would most likefully end up with a lighter rod, the BME rods the engine had when it was a 365 cuber weighed over 600 grams, it was one of their 396 forgings.
Should I go taper wall, or straight wall? It will basically be a normally aspirated Methanol engine, revs will be just over the 7000 range, if that high at all.
I hope I answered everything
Thanks
AL....
