Bushing 440 rods for .990" pins?

[polkat]

Who does this? My two local shops (within 50 miles!) say no, yet I read about it all the time. Where can the bushing material be found? Is there any websites discussing this? Thanks!

 

[Cranky]

Got a thread going over here...hope it's ok to post a link to another site but I've mentioned this board over there too. The guy that would be the 'last word' on this has been busy and is at HRP racing this weekend so he hasn't responded to it yet. I saw him out there yesterday but things were kinda hectic on another racer's car so I didn't bother him with questions. http://www.moparstyle.com/forums/drag-racing-mopars/12753-using-990-pins-stock-rods.html

 

[polkat]

Interesting post over there that I will be following. I agree that the 1.102x.984 bushings might be usable. I didn't see on that thread just where the bushings were available...did you?

My stock Mopar rod pin holes all measure out to 1.093" so the difference for me is .009" plus or minus whatever it takes to get an interference fit. Almost seems small enough to hone the rods out with a brake cylinder hone...just kidding! The bushing inside diameter would have to be honed about .006" with enough added or subtracted to obtain floating pistons...as I don't think bronze bushings can be used with pressed pins... or can they? Then some pin oiling holes would have to be drilled in the rod small end as well.

 

[Cranky]

Dodgeboy8 posted a couple of places in post #4. If I go with what I'm thinking will work, I may just make my own as they are not exactly cheap. I'm pretty sure what the material is but need to find out for sure before going out and buying some stock but I may already have some....

http://www.summitracing.com/parts/MAN-42327-8/

http://www.summitracing.com/parts/ESP-B1040/

 

[Meep-Meep]

Well, it's only about .100" difference. Could it be that the difference in weight between the two pin sizes makes a big enough difference at high RPM? Either that or the piston manufacturers are trying to standardize their piston production to the more common Chevy dimensions. I wouldn't go out of my way to change the size but modifying for floaters is not so bad for future disassembly and reassembly. Ford FE's are all floaters and it doesn't seem to bother them.

I spoke to a guy that had the pin bores honed out in his 440 rods to about .001" over and just ran them like that. Steel on steel. The trick there is to have enough clearance to allow oil to get in. He said there was never an issue. Whatever works I guess.

If you're making your own bushings you might consider something like this http://www.ampcometal.com/en/index.php?page=a18ext or use the already made stuff as you pointed out. Probably a lot less headache that way!

 

[Ron 73]

Id like to have 1/2 the IQ you fellows have with these engine's. I might catch up to Sox. OH. You all don't know her, she's my beagle, my kid's decided I need as im alone 99.9.9 percent of the time. Ron...

 

[Cranky]

Well, it's only about .100" difference. Could it be that the difference in weight between the two pin sizes makes a big enough difference at high RPM? Either that or the piston manufacturers are trying to standardize their piston production to the more common Chevy dimensions. I wouldn't go out of my way to change the size but modifying for floaters is not so bad for future disassembly and reassembly. Ford FE's are all floaters and it doesn't seem to bother them.

I spoke to a guy that had the pin bores honed out in his 440 rods to about .001" over and just ran them like that. Steel on steel. The trick there is to have enough clearance to allow oil to get in. He said there was never an issue. Whatever works I guess.

If you're making your own bushings you might consider something like this http://www.ampcometal.com/en/index.php?page=a18ext or use the already made stuff as you pointed out. Probably a lot less headache that way!

I've seen the floating rods without the bushing before but it does wear faster than having bushings. I picked up a 70 Cuda drag car years ago with a trashed transmission and it was done that way but the pins showed wear and so did the rods but the engine probably had 400+ passes on it. That's a cheap way out and can probably be good for a couple of seasons depending on how many passes you do in a year, then spend the money and do it with bushings and new pins. And thanks for the link!

Id like to have 1/2 the IQ you fellows have with these engine's. I might catch up to Sox. OH. You all don't know her, she's my beagle, my kid's decided I need as im alone 99.9.9 percent of the time. Ron...

I think most of my IQ left me back at the 'office'

 

[polkat]

Was thinking about this a bit. The whole idea of this post is a cheap way to get pistons that use a .990" pin onto stock pin mopar rods. Since the pin holes in the pistons are themselves floating, why not just hone out the piston pin holes to fit the 1.090" pins? The pins will still be a press fit onto the rods. I have no doubt that there's an element of stupidity in this idea, but I can't see it. Wouldn't this be easier?

 

[Meep-Meep]

That's .100" of material that needs to be removed and that's a LOT of honing, more than I would want to do. No matter how you would go about removing that much material you would have to set the piston up so the pin hole is bored straight exactly following the existing .990" hole - times 8. No thanks.

 

[Cranky]

Yup.... and I seriously doubt you'd find any automotive machine shop that could or would do it. It could be done tho but part of the reason why I want to use the smaller pins is for weight reduction. I could probably do it but it wouldn't be cheap. Bushings would be a LOT cheaper lol

 

[Bruce]

You also need to replace the rod bolts with ARP bolts and have them re-sized along with bushing the pin end. It would be cheaper and better for you to bur aftermarket H-beam rods with the .990 pin size. They are much stronger I never use stock rods in any of my motors. I've been in the business over 30 years.

Bruce Toth Toth Performance

 

[Cranky]

The rods in question already have ARP's. Even though I don't have a store front, I've been in the game since 75 and got my machinist 1st class cert in 83 (not as an automotive machinist tho) and have the tools to check for straight and length. I've also run many engines using stock rods and am not afraid of them so long as they pass my inspection process. Metal fatigue? Still have a few sets from very low mileage passenger cars and still have one set of new ones laying around. I can understand using aftermarket rods for fast heavy cars but for lighter ones running high 10's with an automatic.....waste of money imo. A lot of people won't use the 'junky' 6 pack rods either but we've gone 10.70's using the heavy L2295's with a 4 speed launching at 6 grand and shifting at 6800....but the car was only 2880.