Gennie Hurst Engine Mount Trim???

I'm mocking up a 327 in a Model A frame and I noticed my Hurst engine mount hits the timing chain cover when installed.

Figured that was no big deal and might need to make some ~1/4" spacers to space it out a little and it'd be good. I then went to install a stock harmonic balancer and the balancer won't go on because it hits the bottom of the Hurst mount.

Do these really need to be "trimmed" to fit?? I hate to start carving on this thing or wth am I missing here?

 

Hurst made two mounts, one with a single bolt pattern that fit 283/327 with a 6" balancer and one with 8 bolt holes that fit 327, 348/409 and BBC with 8" balancers. I've seen them trimmed to fit but wouln't cut a genuine Hurst myself.

 

Can he put a 6 inch balancer on an engine that had an 8 incher, or does that mess up balance ?

I remember some of these Hursts had a deeper drop than others, like you mentioned, landseaandair.

Don

 

A 327 is internally balanced so that is an option.

 

To clarify my above post, the smaller balancers should all be neutral balance and many choices available.

 

Here's the other style mount.

 

The one I have is with the single bolt pattern. BUT...I checked the balancer and it's 6 3/4" .
I wonder..is there a smaller balancer that will work??

 

Are you sure it is a Hurst mount ? Ansen and some others were making them back then. Hurst generally stamped a part number on theirs and if you tell us that number I will look in one of my old catalogs to tell you what the application is.

Don

 

Thanks Don I appreciate that.
Looked all over it and nothing stamped in it other than "HURST" on the drivers side.

 

Did a quick check and it seems like 6" balancers are less common than I thought. Here's a couple cheaper versions.
http://www.summitracing.com/parts/PFS-80010/

http://www.jegs.com/i/Scat/942/D-80010/10002/-1

 

Let's see a picture of the front of your engine and a picture of your mount.

Don

 

And here is a picture I found on an old thread of the shallow Hurst mount that should work with the 6 inch damper.

 

Here's what I've got. I've always thought you could use a stock 6 3/4" balancer with these but appearantly not??

 

They came with 5/16 spacers then went between the mount and the block. There were two different versions because Chevies came with different sized balancers but your problem now is that you need spacers.

 

If you look at the red primered one I posted, it looks like the part at the very bottom of the mount is trimmed away slightly for clearance, and yours is not trimmed back. It could be that yours is a very early Hurst, made to work with something like a 265/283, and those dampers might have been smaller in diameter.

Is the problem that if you bolt up the mount and then try to put the damper on it is too big in diameter ? If so, by how much ?

Don

 

Is the problem that if you bolt up the mount and then try to put the damper on it is too big in diameter ? If so, by how much ?

Don[/QUOTE]

Yeah I've got two problems.

One is the mount hitting the timing cover which porknbeaner clarified with the 5/16 spacers needed,so check that off.

The second is exactly what you stated in that the diameter of the balancer (6 3/4") is too big so it hits the bottom of the mount. Not by much at all....like an 1/8" if I had to guess.

 

A lot of those balancers got switched back and forth over the years. His small journal motor is internal balance and all the harmonic balancer does in theory is dampen harmonics.

 

Let me run another possibility by you. Does your motor have provisions on the sides of the block for motor mounts? If so, it looks like you have nothing like steering gear in the way, and you might want to consider running side mounts.

I realize you may want to use the Hurst mount for nostalgic reasons, but the Hurst mounts were only used as a means to an end and when side mounts became available they pretty much took over. For one thing it takes a lot of stress off of your bellhousing, and it also doesn't interfer with using a mechanical fuel pump.

If you want to use the Hurst mounts, I get it, but just thought you might want to consider another route.

Don

 

I'd cut the Hurst mount. They're not rare, I see them at swap meet for $20 or less frequently out here. I bought one for $5 that's been sitting on my sideyard waiting for the next project that needs one.

How does moving the engine mounts 6" further back on the block "take a lot of stress" off the bellhousing? Seems the forward mounts would stabilize engine rotation better. Not trying to be argumentative, just trying to understand your logic.

 

By moving the mounts back the engine is better balanced with less of the weight on the back. People started having problems with Hurst type front mounts and aluminum bellhousings, like on th350 transmissions, because of the weight and stress put on that long run between the front mount and the rear tailshaft mount.

When I was designing the engine mounts for the 394 Olds in my rpu project I had to make a front mount because that series of Olds doesn't come with side mounts. I thought I could get away with just a front mount and a tailshaft mount, but some members on another forum took me to task on it, and once I looked at it I realized they were right. So I added a set of mounts on the bellhousing to support the motor better.

I'm not saying the Hurst mount would 100% for sure cause him problems, I was just suggesting another way to go.

Don

 

You should run a mid mount with a hurst type of mount. I have run them without but you are better off running a mid mount.

 

I may be wroung but I think only the early 327 is Internally balanced

 

1932 Ford motor mounts well bolt right up to your Chevy and to your crouse member.why mess with what wont work

 

All SBCs were internal till the 400s came out. Some cranks had an ear on the back but flywheels and balancers were neutral. The 3 3/4" stroke of the 400 required an external weight front and rear. The later model 350s also had a special counterweighted flywheel because the one peice rear main seal didn't allow for the "ear".

 

Thanks guys for all the input and information.

For this car I am wanting to go with a hurst mount (in lieu of side mounts) with biscuits and plan to run mounts off the bellhousing as well for the 4 speed.

I was surprised when a stock balancer wouldn't clear a NOS hurst mount designed for a sbc.

I can't bring myself to start wacking away on this thing so I think the solution is to go with a 6" balancer which should give me about 3/8" clearance. Not much but enough and that way I'm not butchering the mount either.