Boss 302 crankshaft question

I have an opportunity to buy a Boss 302 crankshaft for $100 (maybe a little less). This is a forged steel crankshaft good for as many horsepower and RPM as I would dare put into it. I am told it is in new, unused condition. Here's the catch - the rod journals have been turned to Chevy size (2.100 inches). As I understand it, these journals are slighhtly under-sized (stock 302 rod journals are 2.123"), but that rods are available (e.g. Crower Sportsman for $570).

I guess this effectively increases (slightly) the rod length (which improves rod ratio which is a good thing) and also results in slightly improved friction characteristics due to the smaller journal diameter and bearing area.

Aside from the oddball rods needed, are there any other problems with this crank? Any reason I should stay away for $100?
 
If it uses Chevy Rods, then it uses Chevy Pins which means new pins and of course it will need new pistons. If you are building the motor from scratch, this won't matter.

You have a lot of choices with rod lengths for Chevys. 5.400" would be reasonable for this motor. Just make sure your piston supplier is told about all of this.

By the way, a lot of aftermarket Ford cranks are made for Chevy rods these days. It is not at all unusual.

Kevin
 
I am using a Boss 302 crank shaft in my engine. My unit is a NOS piece I have had from my owning a Boss 302 and always buying spare parts. I am using a Explorer Roller Block with the one piece rear main seal, so I cut off the flange by the seal surface on the crank and also installed a stainless speedy sleave where the rear main seal rides as the Boss Crank has slight grooves cut in the seal area because they used a rope seal on some. The Neoprene seal (one piece or two piece) works better with the grooves covered. I am using standard Ford dimention crank. I would have the crank magnafluxed and also ringit with a small hammer, as many of the Boss stuff was run pretty hard and they are 34-35 yrs. old /ubbthreads/images/graemlins/smile.gif

Vic
 
Well, this would be an opportunistic purchase for that long-rod aluminum-block 321 (4.125" bore by 3.000" stroke) that I can see myself building a few years down the road. Except I've been thinking about doing it with a flat-plane crank in an effort to get that Ferrari sound! /ubbthreads/images/graemlins/laugh.gif So, yeah, I could assemble the pieces over time. Vic, can you describe the "hammer test?"
 
Mark,

Metallurgy has come a long way in 40 years. 4340 today is much better steel than it was in the 1960s. If you are planning this for an engine with a $4,000 block that you intend to go all out on. You can get stronger cranks made today. There is not a lot of nostalgia value in it being a real Boss 302 crank if it needs Chevy rods. If you are going to put it in an engine like that, I would seriously consider a high quality new crank instead.

Kevin
 

Rick Muck- Mark IV

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If you don't want it, I will take it.....and I'll go $105.00 so you can have some profit!

Rick /ubbthreads/images/graemlins/grin.gif
 
The hammer test consists of taping each crank cheek with a small hammer (usally a ballpein) and the crank should ring like a bell, a suspect crank will produce a light thud or clunk sound. I have read that some of the old time racers (Garlits etc. ) believed more in this than magafluxing. If you plan on building a high buck engine I would surely use a crank made from modern materials and get som the benifits of knife edging, etc. I was fortunate with my crank as it was new in the box and I just made the mods as I described, and by the way my engine runs fine.

Vic /ubbthreads/images/graemlins/cool.gif
 
Here is a pix ofmy engine with the Boss Crank installed.

Vic
 

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If my memory serves me well, the 1969 boss cranks were somehow different than the 1970 boss cranks...could be a cross drilling issue or perhaps something else. I do recall the '69 cranks being more desirable but could not tell you if the forging numbers were different. Anyone else know?
 
I have a Steel Ford Boss 302 crank (3.00" stroke) that has the mains cross drilled (as were only 69's) however it does not have the plugs in the crank throws that were held in with snap rings (like 427 FE). It has markings from LA Billet who I believe was absorbed by Cola but is now out of business. It is a nicely done .010/.010, with heat treating, looks to be nitrided. It has 1970 casting #. My belief is LA Billet modified (3 smaller length keyways instead of one longer one) this one OR was purchasing forgings from Ford and finishing them in house. I will soon be building an engine for which this crank was purchased. I just don't know enough about Cross Drilled cranks or their associated bearings to feel comfortable in its use. Want to use coated bearings, Any of you fellows using this type of crank in a hard charging application. I want to be able to use 7500 RPM. Just want to get the warm fuzzies from those ahead of me.

Thanks.....Rick
 
Colonel how does that pencil out? Smaller diameter = larger bearing surface? Ahhhhh...is THAT English Math?
 
Tooo much mustard??

IIRC & its been a decade or three, early pre 69 CHEV 302 cranks were 2.000" rod & 2.300" mains with 2 bolt mains, later were 2.100" rod & 2.450"? main with 4 bolt main caps.

Smaller journal was preferred for LESS bearing speed & lighter crank weight along witrh smaller counterweights & therefore less windage, down side was the 2 bolt main which was fixed in a variety of ways.. bearing spacers on mains to allow later block, aftermart outer splay bolt caps for early blocks or simply run 2 bolt with good hardware, @ 5 liters it was just about safe to run 2 bolt mains.
Nowdays its common to run Honda size (~1.700") rod journals on all three USA V8's if your getting serious.
 
Just a quick question - I once picked up a ford block from a barren field and upon ripping it apart the engine bearings said something on them. It was many years ago but I thing they had "boss" or "Cleveland" on them. We rebuilt as regular 302 afterwards...what did I have?
 

Neil

Supporter
I have a Steel Ford Boss 302 crank (3.00" stroke) that has the mains cross drilled (as were only 69's) however it does not have the plugs in the crank throws that were held in with snap rings (like 427 FE). It has markings from LA Billet who I believe was absorbed by Cola but is now out of business. It is a nicely done .010/.010, with heat treating, looks to be nitrided. It has 1970 casting #. My belief is LA Billet modified (3 smaller length keyways instead of one longer one) this one OR was purchasing forgings from Ford and finishing them in house. I will soon be building an engine for which this crank was purchased. I just don't know enough about Cross Drilled cranks or their associated bearings to feel comfortable in its use. Want to use coated bearings, Any of you fellows using this type of crank in a hard charging application. I want to be able to use 7500 RPM. Just want to get the warm fuzzies from those ahead of me.

Thanks.....Rick

Rick, I would recommend King bearings.
 

Randy V

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Just a quick question - I once picked up a ford block from a barren field and upon ripping it apart the engine bearings said something on them. It was many years ago but I thing they had "boss" or "Cleveland" on them. We rebuilt as regular 302 afterwards...what did I have?

Are you sure that the bearings didn't say "Clevite" or "Michigan" on them? I can't ever recall seeing "Cleveland" or "Boss" embossed on a bearing shell..
 

Brian Kissel

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I work for Federal Mogul, and have been building engines for over 50 years. I have been involved with several industry trade shows, and have used probably every manufactures bearings. In the past 50 years, I have never seen anything like boss or Cleveland on the bearing shells. I'm with Randy on this I believe Clevite is what you probably seen.

Just my opinion, and experience.

Regards Brian
 
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