Monday, March 29, 2010
ENDYN I use 4032 alloy on our normally aspirated pistons, unless the customer tells me ....
Hi there, Brian from Wiseco here. Sorry to hear your having issues with your Endyn pistons. Very commendable work doing research on the alloys though. Your descriptions of the alloys was first rate. You're smarter than most of our competition is I have some more info that I hope helps. Wiseco builds almost every sport compact piston w/ 2618 (unless specially requested by customer). All Endyn's are 2618. The reason for this is: to make big power w/ a small engine you either a: run a turbo, b: run nitrous, c: spin the be-jesus out of it. So we try to cover all the bases and go straight to 2618. 2618 does expand more than 4032 due to less porosity. We actually build the same clearance into the bottom of the skirt though as it only see's about 250 degre's of oil temperature.
We build the skirt taper of the pistons differently depending on the alloy and forging design. We do build two different primary styles of forgings. Strutted (like our IRL, CUP, Trans Am, etc.) -extremely light strong, but also so ridged that shape becomes very important; and slipper or full round (very similar except the band that goes out to the cylinder below the pin and heavier). These are more forgiving, but not as strong (this style is what the other piston companies sell as well). If you can furnish the part number from your box, I can tell you which forging was used. We offset almost all of our pins as well like the O.E's to quiet the pistons down. This is an expense that most of the other companies don't want to mess with, but for you guys running on the street, we've found it to be very helpful. I personally run the new 11.7:1 K566 series strutted piston in my own test engine and found them to be ABSOLUTELY silent on start up. I do not yet have 500 miles on it yet, which is the real test!, but I would expect them to develop a small amount of clatter on startup for about a minute, but certainly not to the extent you are experiencing. If you are running a slipper skirt or "full round", I would expect even less noise as we design those w/ less taper. I found the numbers for our pin bore clearance and Endyn's "usual" piston to wall clearance to be correct. Perhaps even a little to perfect which brings me to my next point. If the engine is taken apart yet, I'd HEAVILY suggest you have it taken to another shop and have piston to wall clearance checked again. Have them check taper in the cylinder bore as well. Measuring point is 1.300" below the oil ring groove on all our pistons. We've got a near constant problem of shops used to building chevy's putting in an extra "thou" of clearance knowing that it's better to rattle than seize. Honda's are a different animal though. If you go to another shop, they will likely give you the straight answer. Now, if you do find that they honed the engine too large, your only economical choice is to have the pistons coated to try and take up extra clearance. I'd recommend Polymer Dynamics in Texas at 713 694 3296 as they do many of the coatings for our Pro customers. Please give me a call at 800-321-1364 ext. 3177 if I can be of further assistance. Thanks, Brian Nutter-Wiseco Piston Co.
We build the skirt taper of the pistons differently depending on the alloy and forging design. We do build two different primary styles of forgings. Strutted (like our IRL, CUP, Trans Am, etc.) -extremely light strong, but also so ridged that shape becomes very important; and slipper or full round (very similar except the band that goes out to the cylinder below the pin and heavier). These are more forgiving, but not as strong (this style is what the other piston companies sell as well). If you can furnish the part number from your box, I can tell you which forging was used. We offset almost all of our pins as well like the O.E's to quiet the pistons down. This is an expense that most of the other companies don't want to mess with, but for you guys running on the street, we've found it to be very helpful. I personally run the new 11.7:1 K566 series strutted piston in my own test engine and found them to be ABSOLUTELY silent on start up. I do not yet have 500 miles on it yet, which is the real test!, but I would expect them to develop a small amount of clatter on startup for about a minute, but certainly not to the extent you are experiencing. If you are running a slipper skirt or "full round", I would expect even less noise as we design those w/ less taper. I found the numbers for our pin bore clearance and Endyn's "usual" piston to wall clearance to be correct. Perhaps even a little to perfect which brings me to my next point. If the engine is taken apart yet, I'd HEAVILY suggest you have it taken to another shop and have piston to wall clearance checked again. Have them check taper in the cylinder bore as well. Measuring point is 1.300" below the oil ring groove on all our pistons. We've got a near constant problem of shops used to building chevy's putting in an extra "thou" of clearance knowing that it's better to rattle than seize. Honda's are a different animal though. If you go to another shop, they will likely give you the straight answer. Now, if you do find that they honed the engine too large, your only economical choice is to have the pistons coated to try and take up extra clearance. I'd recommend Polymer Dynamics in Texas at 713 694 3296 as they do many of the coatings for our Pro customers. Please give me a call at 800-321-1364 ext. 3177 if I can be of further assistance. Thanks, Brian Nutter-Wiseco Piston Co.
Let me elaborate a little more on my "rods: good" thing.
Yes, it is true you usually have to spend a little more to balance those rods with your assembly but from what a few machinists have told me it isn't because of the forging of the rod, its just the design of the H-beam.
Also...the reason why i say those rods are good is because i have yet to hear from someone who has broken them meaning the rod itself. It is usually something else that happens first and then takes out the rod. This isn't just my personal hearsay either...this is coming from many race shops and machinists in my area to use them. They have all told me the same thing, they see the rod bolt or something else let go before the rod ever does.
i can give quite a few examples of very high horsepower motors ranging from 800-1200 living with these rods.
Now the cranks are a different story, i will agree with anyone that thinks they aren't very good for a high performance application. I have heard numerous stories of them breaking and just recently had a friend who literally snapped the snout off of his eagle 4340 forged crank ON MOTOR and its not like he has a 9 second on motor car either....it wasn't a balancing issue either in case you ask about that.
These are some of my opinions and some of the racers/machinists around by city's opinions.
The cool thing about stuff like this is that everyone has opinions and makes you consider a lot of stuff you usually wouldn't have before hand
Yes, it is true you usually have to spend a little more to balance those rods with your assembly but from what a few machinists have told me it isn't because of the forging of the rod, its just the design of the H-beam.
Also...the reason why i say those rods are good is because i have yet to hear from someone who has broken them meaning the rod itself. It is usually something else that happens first and then takes out the rod. This isn't just my personal hearsay either...this is coming from many race shops and machinists in my area to use them. They have all told me the same thing, they see the rod bolt or something else let go before the rod ever does.
i can give quite a few examples of very high horsepower motors ranging from 800-1200 living with these rods.
Now the cranks are a different story, i will agree with anyone that thinks they aren't very good for a high performance application. I have heard numerous stories of them breaking and just recently had a friend who literally snapped the snout off of his eagle 4340 forged crank ON MOTOR and its not like he has a 9 second on motor car either....it wasn't a balancing issue either in case you ask about that.
These are some of my opinions and some of the racers/machinists around by city's opinions.
The cool thing about stuff like this is that everyone has opinions and makes you consider a lot of stuff you usually wouldn't have before hand
Sunday, March 28, 2010
Saturday, March 27, 2010
Friday, March 26, 2010
Thursday, March 25, 2010
Sunday, March 21, 2010
Tuesday, March 9, 2010
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