29A conn rods

4tford

4tford

Well-known member
Just going through my bins and was wondering what the demand would be for 29a rods?? Thanks Bill
 
I'm sure there is still some demand for 29A/99A rods, however, many are using the 8ba rods now to build the 59 engines because the 8ba style bearings are less costly and easier to find than the full floating type bearings. The 21A rods are still in demand for those who want to add some additional stroke by off center grinding the crank to the smaller rod journal diameter. I would think you could sell some sets with an ad on Fordbarn and/or the EFV8C/A websites. JMO, JM


ps.....what other goodies are you finding in those bins?:confused:;):D
 
I used these in the hydro and Bonneville engine. they were very popular back in the early years of racing and stood up well under blower and the purple stuff. Unfortunately their expensive and alittle tricky to set up..
Back in the late 50's C&T auto converted late model OHV engines to use these bearings.
 
I was referring to the bearings as being expensive. However the most expensive thing I've ever baught in my life was a 5/32" CHINESE DRILL FROM TRUE VALUE FOR 5 BUCKS Last week.
 
I just recently tore down an 8BA engine that had a 4 inch Merc crank and the earlier rods and one piece bearings(floating type).
I thought it strange, since the later rods would have been scrapped in this engine to put these in. But then I read somewhere that the earlier rods/bearing combo made for a stronger bottom end. Is this true?
This engine was also hot rodded back in the day, because it also had an Iskendarian MAX-1 cam in it.

Ralph
 
As Ol' Ron says, the floating bearings were considered superior in every way in the early years of racing. I use them with my old eighth-stroke crank, and firmly believe this to be so. Of course, I was brainwashed from an early age by an old hot rodder, so use this information at your own risk!
 
Theoretical advantages of floaters are a slight decrease in frictional drag at those bearings and near freedom from the most common type of rod-throwing, which is apparently initiated by big end distortion at high RPM.
The rod tossing when rodders started getting RPM's out of the new overheads is what started the conversions to Ford floaters on drag engines in the mid fifties...some engines (Chevy SBC and Studebaker??) were converted to Ford rods and bearings, then someone...memory says Moon/Potvin...produced special sizes of floaters to allow other adaptations.
High RPM drag engines moved on to aluminum or special or reinforced rods, and soon the factories got interested in performance and offered better rods for some engines.
Bearing development had a major role: The joint/separation area of rod bearings was slightly relieved to allow extra clearance at point of greatest high speed distortion.
Yunick discussed this, and I think claimed credit for studying and detailing the causes of rod failure and the idea of relieving the bearings.
Certain flexi-flyer crank engines hot rodded in the twenties and thirties kept their rods in by curving the bearing ssuface of rod babbitts to allow for crank flex!
 
Spent many years on this board and the Hamb before opening my mouth, and although I know it's been said before, if Bruce Lancaster or Ol' Ron has anything to say, I recommend you listen carefully! Thanks for your tremendous contributions over the years.
 
So, are the rod journals the same size for 59 series motors and 8BA's? If this is true then I have a set of rods & bearings I could use if the crank turns clean at .020 .
OK, this brings up more questions;
Are the mains the same or different?
And what type pistons are needed to run with a 4" Merc crank?
 
Yes they are the same size... Rods and mains, but the main bearings use a thrust bearing that is different... When you go to use the 29A rods, they need to be rebuilt just as much as the crank may need a new grind... You can torque them and measure them, if they're good- go for it- I have yet to find a used flathead rod that did not need resizing... Karl
 
Rod journals are the same. You can use 59 rods on the 8BA, but can't use 8BA rods on the 59 crank because there is only one oil hole in the journal. The front and center main are the same, the thrust bearings are different. Any piston advertised as Merc will work, the pin is closer to the crown on the Merc pistons by 1/8".
 
Thanks all. I started building a 59AB awhile bach and have had some of the work done to it, including the rods/crank and new bearings. It does however have the usual small cracks at the center head bolts. Also one of the valve seats has a damaged area near it on the block. I was told it would be OK as long as I'm not racing it, but it has me worried.
Fast forward to now, I have a nice 52 Mercury engine that I am tearing down and if it all looks as good as what I've seen so far, I may opt to put it in my car instead.
Hence the questions about using parts I already have on hand.
 
If one uses cutters to do the valve seats, with an "interferance angle" of 1 degree, the part of the seat that makes contact with the valve first is the very thin line where the 45 degree cut meets the 30 degree cut. If this is unbroken, the valve will seal... Also, intake valve seats get less stress than exhaust and will be less demanding in terms of perfection... Karl
 
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