Full floater rod conversion to inserts

[Mark's 37]

Can a 37 221 be converted to insert rod bearings?

[flatheadmurre]

Buying a set of scat rods will fix that for you.
Im not sure they will clear in small bores but someone else will know for shure.

[tubman]

I hope this is just a rhetorical question.

[Mark's 37]

Originally Posted by tubman

I hope this is just a rhetorical question.

It is. I have another 37 engine standard bore.

[jonf]

Tubman
Why are you hoping it is a rhetorical question?

[Bored&Stroked]

Sponsored Links (Register now to hide all advertisements)

I would think that the small journal H-beam rods would work - but you may need to clearance the bore at the bottom. Given that you're probably running a stock 3 3/4 stroke crank - there should be even less of an issue than if you had a 4"+ stroker (as the rod angle is less). In the end, the H-beam approach isn't a bad idea - because by the time you invest $200 in rebuilding the rods (and finding somebody who knows how to do full-floaters - the bore finish isn't like insert rods) - and then you pay $200 for a set of bearings, you're 2/3 the way to a set of new H-beams and a set of Buick insert bearings.

If you go this route, let us know if it works out. Also, as long as you can return the rods - might be worth at least checking it out. I don't have any small-bore flathead blocks - or I'd be up for finding out myself.

B&S

[GOSFAST]

Depending on the bore size, I don't believe any brand aftermarket H-beam will go through an early block??

Eagle's has a very slight edge in this area being .050" (nominal) smaller than the Scat's across the span on large ends.

Here's the breakdown:

Eagle H's=(rod & cap) 3.180" across (2.000" journal rods).

Scat H's=(rod & cap) 3.230" across (2.000" journal rods).

Ford 91A-(rod)=3.030" / (cap)=3.250" (This will pass through a 3.060" bore)

Ford 8BA-(rod)=3.170" / (cap)=3.400" (This will pass through a 3.187" bore)

Thanks, Gary in N.Y.

P.S. When Ford engineered the rods they layed them out so none of the caps would fit "through" their respective bores, only the rods/bolts themselves. This was apparently the reasoning behind incorporating the rod-bolts right into the rods, to keep the width's narrow enough for ass'y??

[tubman]

Originally Posted by jonf

Tubman
Why are you hoping it is a rhetorical question?

The timing. Asking about updated bearings just a few days after he gets a car with a rebuilt engine back on the road? Luckily, he had the right answer!

[fordscript]

Biggest issue I see, is the single oil hole on the 37 crank.

[Lawrie]

Buy a set of nos 21a rods ,and stay with the floaters,
the rods are around,you just have to keep looking
Lawrie

[Bassman/NZ]

Floaters are not difficult. I did my first set about a year ago, and after reading everything I could find on it, I just got on and did it. The hardest part was overcoming my fear of stuffing something up.

[Bored&Stroked]

Originally Posted by fordscript

Biggest issue I see, is the single oil hole on the 37 crank.

Whups - I forgot about that little detail! This is why the HAMB is so good! Yes, in retrospect, I would only run full-floaters on a crankshaft with a single oil hole. Now - that is not to say folks haven't put 8BA rods in 239 engines (39 - 48) - with single oil hole crankshafts . . . any some say it worked. (If it could be attempted on a flathead - it was done). Me - I would not chance it as it is technically completely wrong to do.

So - I withdraw my prior babble . . . and say unless you put a later 49-53 crank in that engine (which I've not done, but I'm sure is a bit of work - as the mains are different sizes, oil seal is a different situation, etc..), then you're better off sticking with full-floater rods.

Also, as others noted, unless the engine is bored out to 3 3/16, it will be difficult to assemble, as the big-end of the H-beams, won't fit through the bore.

As others noted - correctly sizing and setting up full-floater bearings is not that big of a deal, just takes time, patience and maybe a couple extras sets of rod bearings for 'practice'.

Whew . . . guess I should have drank a bit more coffee this AM!

B&S

[Ol' Ron]

I have a chapter in my book on setting up the 21A floaters, Which is the same as the 29A, except different numbers.

[tubman]

Is it only me that is seeing a lot of identical posts on here and on the H.A.M.B. and a few folks forgetting which forum they're on?

[Lawrie]

What about a pilot crank,I have one and the rods are 2.00 with two oil holes.
Lawrie

[Brian]

Lawrie is correct; a Pilot crank has two holes per journal and notched 21A style rods to accept the flanged [on one side] lock in shells. All very do-able, if you can find the bearings!!
Normal procedure for Pilots nowadays is to run floaters because of the problem finding Pilot bearings.

[Bored&Stroked]

Only problem, is us Yankees have probably never seen one of those cranks . . . at least I haven't!

[Mark's 37]

The reason I asked about this is that I have the original engine from my 37 on the engine stand. It is standard bore but has one sleeved cylinder with a new piston on an old rod which someone rounded off one of the rod nuts. Now that I have the engine I rebuilt in the car and now drivable I am thinking about how to deal with this one. Using floating rod bearings isn't such a fearful thing since going through the hoops fitting them for the engine I rebuilt. Just brainstorming.

Mark

[Bored&Stroked]

Me, I'd find a set of 91A or 21A rods, figure out what regrind the crank will take and find a set of full-floater bearings to match. I would actually have the rods done first (if used), then get the bearings to correctly fit them, then have the crank ground such that the crank grinder had the bearings and rods in hand. This is the best way to get the correct clearances (telling the grinder exactly what you want).

The bearings I've always liked the best are the Cadmium Silver ones - usually say for "Heavy Duty Truck and Bus" - just a bit softer and tend to be easier on the crank. This is especially true on a 4 1/8" stroker motor (which obviously this isn't).

[Mark's 37]

Originally Posted by Bored&Stroked

Me, I'd find a set of 91A or 21A rods, figure out what regrind the crank will take and find a set of full-floater bearings to match. I would actually have the rods done first (if used), then get the bearings to correctly fit them, then have the crank ground such that the crank grinder had the bearings and rods in hand. This is the best way to get the correct clearances (telling the grinder exactly what you want).

The bearings I've always liked the best are the Cadmium Silver ones - usually say for "Heavy Duty Truck and Bus" - just a bit softer and tend to be easier on the crank. This is especially true on a 4 1/8" stroker motor (which obviously this isn't).

That seems like the ideal way to go about it. The other problem is the rod nuts. I have removed all the cotter pins from the nuts but now realize why the previous owner rounded off one of them. I can't get a 3/8 drive Snap On socket to sit down correctly on the nut. The two ribs on the rod interfere and won't let an end wrench or a socket get a good grip. What is up with that?