Educate me on chevy rods...

[cjshaker]

I'm getting ready to start gathering parts for my next engine. I've always used factory rod/crank ratios with stock throw diameters, so I have no experience with the chevy rod combo. However, I have a good factory steel crank that I would like to use in my next build, but the problem is that it has been machined wider at the rod journals. I'm getting .026 side clearance measurements. Seems this is the number Ford recommended in their performance catalogs if I'm not mistaken. I think that's excessive.

 I want to put this in a street/strip build for a '55 Ford. My question is two-fold I guess. First, would you run that much clearance? It seems to me that it would throw too much oil on the cylinder walls, overpowering the rings ability to do their job. What do you guys think? I know why Ford did it, but practices and materials have come a long way and I don't see anybody running that much clearance even in drag engines.

Second, I know chevy rods have a reduced journal diameter so they require turning the journals down...which has the benefit of reducing bearing speed. A big plus, not to mention the fact that you can get bearings that actually fill the entire width of the rod (for the life of me, I can never understand why FE bearings only cover about 3/4 of the rod width. I mean really...why?)

But are they wider? Can I close up my side clearance some using a chevy rod? Or am I stuck with a perfectly good steel crank that has too much side clearance? The crank is std/std and magged good, so I hate to consider it unuseable.

What do you guys think?

[mike7570]

The chevy rods are wider, you will need to have them narrowed a bit to fit even your widened crank. I used a set of 2.20 journal chevy rods in my TP with a wide journal NASCAR crank and I still had to narrow them to fit. Don't forget to re-chamfer them and you will need to narrow up the bearings also.

[1967 XR7 GT]

Hi Doug

If you don't like the side clearance it has, an option are custom rods with the big end wider to get the clearance to where you like it.  Since you are thinking about going Chevy rods and grinding a perfectly good STD Steal Ford crank so they fit.   I don't know the big end width of the Chevy rod so you may want to find that out first to see if they will even work.  You have to remember that the stroker kits that are now available for the FE are made and ground for the 2.200" Chevy jrl , so that the affordable massed produced BBC rods can be used.

Thanks to mike7570 the BBC rods big end width is now known.

I am going to do a build along the same lines and have been researching my options, some info below.

http://www.popularhotrodding.com/tech/0811phr_427_fe_ford_engine/viewall.html
http://www.hotrod.com/techarticles/engine/hrdp_0811_ford_428_cobra_jet_engine/

The Super Ford Magazine, March 1993 issue, the 474 Stoker Fe article build by former Kuntz & Craft Performance who did a lot of this build for competitors who ran Super Street, Super Gas, Fast Bracket and dirt tracks: It starts with a .030 over 427 block, 3.980" 428 crank, offset ground to a 4.125" stroke on a 2.310" rod jrl which is the same size as the 400M, the rods are the 6.580" 400M rods bushed for a .912" pin which K&C had tested to over 8000rpm. The rods are about .100" longer than FE rods, and the big ends are narrowed to .873 to fit the pins. I picked up the 400M rods some time ago along with the cranks, so I have options.

 So, I could have either of these cranks offset ground to increase the strokes and have a steel crank option thanks to my recent parts research, I found a lot of the FE stroker crank kits now are going to the 2.200" BBC rod jrl size and using the BBC 6.700" rods, so that got me thinking, I could have the 361 crank off set ground to the BBC 2.200" jrl and get it out to the 3.78" stroke and use the BBC 6.700" rods and take the extra length of the BBC rods out of the pistons CH, which reduce the reciprocating weight of the big C/H heavy pistons. And the same with the 391 truck crank, have it off set ground to 3.98" 428 stroke.
     

[My427stang]

Why worry about that much side clearance?   Ford used to recommend more for hot 428s. 

I'd match up pairs to get the most even number and be happy with the room for heat expansion and oil

[jayb]

I measured the big end width of a stock Lemans 427 rod and got 0.875" with my dial caliper.  The BBC rod big end width measures 0.995". 

I would not put a strong FE together these days without using a stroker kit and the BBC rods.  The extra width of the BBC rod bearing makes a huge difference in longevity and durability, IMO, plus you can get them in lots of different lengths without paying customization charges.  Doug, you might add up the costs of the special machine work required to use the BBC rods in your application, and compare it to just buying a stroker kit where the BBC rods just bolt in.  I'll bet it would be pretty close to a wash from a cost standpoint, and you'd get extra cubes with the stroker crank.

[cjshaker]

Well after an interesting night after 60-70mph winds came through, having a big Maple tree miss my studio by 2' as it came down, limbs and trees laying everywhere and still running on generator power, I finally got a chance to read the responses

Thanks for the replys. Wanting to keep the car looking like a vintage racer, I was going to use my old SO block and keep it old school. I wasn't even going to paint the block so it looked like it had been in the car for years. But I did have some second thoughts about using a good SO block for racing seeing as how they are so hard to find now and the value is high on them. Its an original C5 block.

So now I am thinking about a Shelby block and stroker kit for durability. The wider chevy rods seem like the logical choice. Since this may turn in to a father/son race effort in a couple years when my boy gets out of the service I want durability first and foremost. Cost, while a consideration, is not my deciding factor.

So I will save the block and crank for another project and start running some #s for a Shelby/stroker combo with the chevy rods. I can make the block less noticable by painting it black.

Now, to see if I can locate a block, as it seems most suppliers supplys have dried up. Thanks again. There will be more questions since this will be my first stroker combo.

[machoneman]

Barry's site has a nice stroker/bore chart:

http://www.survivalmotorsports.com/FE-Stroker-Displacement.html

[Ford428CJ]

The cool thing about a Shelby block is... You can use a 4.50" Crank and make some BIG cubes out of it. I guess if money is not a problem, Shelby block for sure would be the way to go. Much more stronger and can take a ton of abuse/ HP.

Lot of good advice/ info on using Chevy Rod's. The other good thing.... They are new and havent been abused yet. So you would be the first to tear them up (so to speak). You never know about a 40+ year old rod.

[cjshaker]

Ross, I knew Ford has that exact measurement in their books. I have all the original "Performance" handbooks they put out and recalled seeing it in one.

To me, .026 just seems excessive. I understand Fords thinking in the day, but am surprised they would recommend that number for a non-sideoiler block where the mains are not priority fed. I thought it was more of a 427 endurance type suggestion. I'm a firm believer in getting as much oil flow through an engine as is reasonable, not just for lubrication but also cooling. But since my plans are for a mainly drag car with limited street miles, I was considering a light tension ring set-up and don't feel that flooding the cylinders with oil would be a positive thing. Maybe I'm wrong. That's just a gut instinct and not based on experience.

[machoneman]

I also thought it sounded excessive as all the BBC's we ran and SBC's we worked on (sorry!) all had a minimum IIRC of .018 and a max of .030 with steel rods. Anyway....

Yanked out my old Ford O.H.O. (off highway operation) book and lo and behold, on Page 5 (Critical Blueprinting Dimensions/352-390-406-410-428) rod end play side clearance is:  .025". The page btw makes no distinction on a 427's oiling system and also notes that Boss 302-351C's and Boss 429's also have the same dimension for rod side clearance.

Keep in mind the OEM Ford dimension for passenger car engines may not apply here. The O.H.O. Book and attendant O.H.O Parts Newletters were solely for all-out competition engines. 

[cjshaker]

Now I'm going to have to break out my old Ford performance brochures and have a look-see...lol

As a side note, one engine I built (a hot street engine) years ago, I had a problem of the rod sides 'catching' the crank. After it was built I had it dynoed and found fine metal particles in the filter. After tearing it back down the rod problem was what I found. They were Eagle rods and I wondered if it was a clearance issue (it was .020), rod side finish or metalurgy. Not wanting to buy another set of rods, I cleaned up the sides with fine sandpaper (yeah, I know. I was cheap) and all but polished the sides. The problem never reappeared. Only time I ever saw that happen.