351 rods and custom piston questions

fastsc92

Registered User
OK, i'm not going to build the motor now, but in the future i plan to make it as strong as possible. I'm pushings close to 380hp at the crank, all on a stock bottom end thats making my cringe just thinking about it. I've done a search and havent really found the info i was looking for. Here are my questions

I can just buy a set of 351 h-beam rods? Pressed pin or bushed pin?
Are they 351W(5.956") or 351C(5.780") rods?
Can i get a rod bearing set for a 351 and will it work ok?
What info is needed for custom pistons to be made? Is there are Ross/diamond part number?
And why do custom pistons need to be made....is it something about the rod width or specs?
How much can I expect to pay for a set of pistons?

Rods i can find on ebay for about 250 for a set of 8.
 
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yes 351 W rods and JE Ross OR Diamond pistons....Im unsure but ya need a lil machining to the crank and possably the bearings
 
ya i just wasn't sure what exactly is needed..and why pistons are required. Is it because the rods are a tad bit longer? It looks like the rod journal size is the same, so it should fit on the crank without any machining. I know a lot of people here have set-ups like these. How did they work out for you, and just a shot at prices for the pistons. Any machining needed on the crank end? OR just some custom pistons with a set of 351 rod bearings...or can you use a 3.8l rod bearing set?
 
Pistons

I got diamond 8.5:1 forged pistons at a .030 overbore for $70 per piston that includes wrist pins.
 
i was keeping an eye on a set on ebay....SCAT h-beam rods...set of 8....5.956" long....brand new and ended up selling for $258. I just wanted to know if this is the correct rod, what bearings to use, i know custom pistons, but what about machining of the crank/rods/bearings?
 
The 351 rod is longer thus requiring a piston with a relocated wrist pin...I believe one of the journals on the crank needs to be turned down. Ford did something with the SC cranks so they wouldnt eb put into non SC blocks..Ask someone who knows..This motro was something I didnt care to put together so I had someone with experience do it. Also I paid 200 for my H beam rods on Ebay..Guy bought them then didnt use em..My gain his loss!!
 
nothing to the crank

ford ...turned down I believe it to be #4 main bearing journal..on the crank ..so it wouldn't fit in a NA block or vise versa ...so ...something to watch for ....on your rebuild ...when it comes time for main bearings ...they won't be all the same ...dave
 
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Ahh ok..Wasnt sure if it was the actual crank itself or something to do with the rods..I feel so much better now haha
 
what can i use for rod bearings though..351 bearings or stocker? I was aware about the #4 main being .010" undersized. I am correct about the specs?...the rods need to be 5.956" long from a 351W..and not a 351 clevland.
 
My setup is:

351W H-Beam rods
351W rod bearings, hand radiused on one side for crank radius clearance
 
rods...

If you end up not being able to get that good of a deal on rods, I sell them. Email me for info. I used 351W rod bearings in my setup with Diamond Pistons. I did not have anything done to the rod bearings and have not had any problems. Just check your rod bearing clearances.

supercatxr7 at yahoo.com
 
If the crank has not been cut or if it has been cut but done properly, you will always need to radius the rod bearings if they arent already done. When getting a crank cut, make sure the shop is aware that there is a radius on the crank and you want it to stay there, if they cannot keep it, go somewhere else. This radius is a crucial part of the cranks strength.

Paul
 
what does radiusing the rod bearings mean? Given the surfaces are good, i was planning on adding the bearings and checking for clearnance like normal stock type rods and call it a day.
 
Let me correct my statement. You should always chamfer the bearings if they aren't already done when the crank still has its rod journel radius. A radius in this discussion refers to the point of transition from the rod journel surface at its edge to the counterweight. Instead of being a sharp 90* turn, it should be a smooth sweeping bend. If you look at a stock SC crank, you will see what I mean. With regard to chamfering the bearings, an angle (about 45* if I recall, DLF could tell you since he has personally done it recently) needs to be cut on the edge of the bearing that sits near the radius on the crank.

Paul
edit: stock SC bearings have the chamfer already cut in them. If you go to aftermarket bearings such as clevite 77 for the H beam rod, you will need to cut the chamfer. You may also have to cut a chamfer in the rod as well.
 
The 351W crank has shared rod throws, unlike the the rod throws on the SC crank which are offset and individual. Because of this, one side of the 351W rod bearing, which isn't close to the crank radius on the 351W crank, is close to it on the SC crank. The bearings just need to be radiused slightly to ensure that there isn't any interference.
 
oh ok....i understand now. Is this just done by hand by carefully filing(hand file) the edges of the bearings and if need be, the rods as well?
 
fastsc92 said:
oh ok....i understand now. Is this just done by hand by carefully filing(hand file) the edges of the bearings and if need be, the rods as well?

Yep, my machinist and I just sat there with some emory cloth until we were happy :)
 
here's a pic that i sketched up quick. I hope you can understand it. I just want to make sure that i know where the material needs to be taken off the bearings. Do i chamfer the edges as in the top example or the bottom example?
 

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Well, I don't see any pic....

You're overthinking this. Once you've got the rods and bearings in hand, it'll be obvious what you need to do.
 
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