Can 312 crankshafts fit into a 292 Y Block?

[Bigmacmclaughlin]

My 56 T-Bird had a 312 Y Block with a broken main bearing mount. I want to reuse my 312 crank shaft and connecting rods on a 292 Y Block. Are there any problems that I need to know about before I look for a machine shop to do the work? I haven’t been able to find a 312 block that is rebuildable in my area. Any experienced opinions will be appreciated. Thank You..

[Dobie Gillis]

Yes, they can. You turn the 312 crank to 292 main dimensions and bore the block for 312 pistons. All that is contingent on your 292 block condition regarding core shift and water jacket erosion. You'll also need to use a 292 rear main seal so that area will need to be turned, too. When the dust settles you'll have a better 312 than Ford built.

[Bigmacmclaughlin]

Thank for the reply. Can I still use my 312 oil slinger or do I need to get a 292 oil slinger?

[Dobie Gillis]

If you choose to use the 312 crank as is, you have to line hone the mains and either grind the rear slinger down or make the groove in the block deeper as well as accommodate the larger rear main seal. The 312 bearings and rear main seal are more expensive.

If you choose to turn the mains to fit the 292 block, you have to turn the seal surface and you still need to do something about the slinger. This way you can use cheaper bearings and seals and since the main diameter is smaller, there is also a slight benefit to the power output though it might not be anything you could notice on a street engine.

Another thing to be aware of is not all shops can turn the rear main without also removing the slinger. The slinger is not absolutely necessary. Many strokers run without them. You can research and decide if it is important to you but it's a good question to ask the shop, if they can machine the crank while keeping the slinger.

On the really high performance stuff, 292 blocks, and therefore 292 mains are usually used.

[Bigmacmclaughlin]

Thank You all for your helping me.

I am a new member on the Ford Barn and this is my first Y Block rebuild. I appreciate everyone who has offered their experience and knowledge to this Y Block rebuild project.

[dmsfrr]

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Originally Posted by Bigmacmclaughlin

Thank You all for your helping me.
I am a new member on the Ford Barn and this is my first Y Block rebuild. I appreciate everyone who has offered their experience and knowledge to this Y Block rebuild project.

If you haven't seen these yet, a good book and a very helpful information link...

http://ford-y-block.com/technical.htm
.

[darrell]

its a good book with just a couple of goofs.

[KULTULZ]

Originally Posted by Bigmacmclaughlin

Thank for the reply. Can I still use my 312 oil slinger or do I need to get a 292 oil slinger?

Are you describing the front or rear slinger?

[TedEaton]

When machining the 312 crankshaft to fit in the 272/292 main saddles, the 312 crankshaft rear seal surface and rear oil slinger O.D. must be also machined to the 272/292 sizes along with the main journals. Because the rear seal area is so narrow, many shops do not have a narrow grinding stone in which to do the seal area and retain the rear oil slinger. Hence the number of those 312 crankshafts that have the rear oil slinger removed so that the seal surface can be machined with the wider grinding stone. A tip here is to machine the rear oil seal surface in a lathe to within 0.010" of the desired size which will help to prevent chatter on that narrow crankshaft grinding stone and having that stone break prematurely. The oil slinger itself can be cut down to the desired size in the lathe as final finish on that is not a wear factor. My preference is to retain the rear oil slinger but those engines that I have had to put together without the oil slinger did just fine with a neoprene rear oil seal. Ted Eaton.

[Bigmacmclaughlin]

Thank You Ted Eaton for your expert experience on this subject. I didn’t expect to get such a publicly famous Y-Block expert involved in this thread. Thank You again for your information on 312 crankshafts.

Sharing your time and Y-Block experience with Ford Barn members is very valuable for many of us and especially for me and my Y-Block project.

Many owners of Y-Block engines want to keep these vintage engines running for future generations to enjoy. I am just one of those people trying to keep a Y-Block Ford on our public roadways for others to enjoy.

[Bigmacmclaughlin]

Thank You for the question.
I am not sure if I need to find a 292 oil slinger or just continue to use my 312 oil slinger. I was describing the front mounted oil slinger (cone shape on crankshaft) next to the timing chain sprocket.

Will the 312 front oil-slinger still fit on the crankshaft when installed in front of the timing chain? If not, what options are available?

[TedEaton]

The front oil slinger behind the timing cover is the same for all 1954-1964 Ford Y engines.
Likewise for the damper which is vehicle specific and not engine size specific. Just keep in mind that the Thunderbirds require a different damper than what you'll find on a passenger car, pickup, or truck. Ted Eaton.

[Bigmacmclaughlin]

Thank You Ted Eaton, the information you posted is very helpful.

[dmsfrr]

Originally Posted by TedEaton

. . . Just keep in mind that the Thunderbirds require a different damper than what you'll find on a passenger car, pickup, or truck.

Bigmacmclaughlin, while the engine is being repaired could be a good time to refresh the damper pulley. The rubber mounting layer inside the weight ring dries out with age allowing the ring to slip and creep toward the timing cover.
Failure at speed can cause significant damage.

A special tool is made for pulley removal.

Either of these shops can rebuild the crankshaft damper pulley you have.
https://damperdoctor.com/

https://www.damperdudes.net/
.

[Bigmacmclaughlin]

Thank you Ted Eaton, great idea!

[cars2cool]

Originally Posted by dmsfrr

Bigmacmclaughlin, while the engine is being repaired could be a good time to refresh the damper pulley. The rubber mounting layer inside the weight ring dries out with age allowing the ring to slip and creep toward the timing cover.
Failure at speed can cause significant damage.

A special tool is made for pulley removal.

Either of these shops can rebuild the crankshaft damper pulley you have.
https://damperdoctor.com/

https://www.damperdudes.net/
.

Can we get info on where to find that puller please?

[dmsfrr]

Originally Posted by cars2cool

Can we get info on where to find that puller please?

Other places may sell something similar that works. When I found this one to include with an order of other parts from them I didn't need to keep looking.

https://www.classictbird.com/Tool-Da...oductinfo/TL7/

If you know other Baby Bird owners in your area one of them may have a puller, available to borrow.
.