Scat Crank for model A rear main seal

[lazlobassett]

I'm assembling my motor and found the rear main seal area on the Scat crank is larger than stock and will accomodate a small block chevy 2 piece seal. Seems like a good idea but i am having difficulties finding if there is a kit or something to make that work. I did call scat yesterday and they referred me to a guy in california but he just machined someting on his own. I can do that ( spent some time not sleeping thinking about it) but thought a kit would be faster/easier.
It's too early now to call the left coast but i woke up thinking about it.

Cheers!

matt

[lazlobassett]

I have found there is a kit made for this. I'm going my own way, today I used the original holder to cast a " blank" I can machine to hold the sb Chevy seal. It came out well will post pix if there is any interest. I have done a similar post to the hamb " banger meet" thread.
Cheers!

[d.j. moordigian]

Matt,
Yes, post the photos, please. Also, who makes the kit?

[MikeK]

Lazlo, Is that Petrobond I smell?

[lazlobassett]

Petrobond? Don't know that one.

the kit is made by Dan McEachern, [email protected] 510-532-8228

Yesteday I took the original rear seal holder, added a little tape and used it for a sand casting pattern.

I made 3 castings one of which I considered to be useable.

I use scrap aluminium, preferably things that have been machined, billitt things ( don't like them anyway) sometimes using previously cast bits machine " gummy" Also I get the molds all sorted before heating the metal, if the metal is molten too long it gets more gas in it making for porous castings.

I am neither a machinist nor a foundry guy, just mess around and stumble through as best I can. I'm sure many here know more and better than I.

[lazlobassett]

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TOday I set to machining the good casting.

It was a little tricky as there are no true surfaces to measure/machine off. In hindsight i should have flycut one surface and worked off that but didn't think of that until i was in deep.

It seems to have worked out, I had to use shims to cut the lip the seal mounts to in a consistant way.

Tomorrow I'll machine the main cap and make a insert to hold the other piece of the seal. here's some pix from today's efforts.

Before I got too crazy I fit the blank to the block, there was some shrinkage as expected but it will work.

Then it was time for the Mill.

[lazlobassett]

Well first casting was a fail. The seal was too far inboard. Today I made a new casting with more " meat" and I am sure it will work fine.

Do other people do stuff like this or just buy things? I kinda wonder , some of my friends look at me kinda weird, like why do you do these things? Just go buy it...

Doesn't seem to be much interest here so either everyone does this sort of stuff or you all saying, whats wrong with that guy...

[MikeK]

Originally Posted by lazlobassett

Well first casting was a fail. The seal was too far inboard. Today I made a new casting with more " meat" and I am sure it will work fine.

Do other people do stuff like this or just buy things? I kinda wonder , some of my friends look at me kinda weird, like why do you do these things? Just go buy it...

Doesn't seem to be much interest here so either everyone does this sort of stuff or you all saying, whats wrong with that guy...

Don't rush off for that frontal lobotomy just yet. (There's a waiting list here on Fordbarn!). Sure, there's interest. You have over 400 viewings of this thread so far.

There are not too many here that scratch fabricate mechanical parts, so not tons of comments on this tiny aspect. Plenty of guys here who can do magician sheetmetal and welding work, but most, as you stated, will take the easy route and buy something if available. That doesn't mean no interest, just a crowd unable to make relevant comments.

Many will overlook a thread entirely if the tag line for it is not within their scope or interests, and I must say starting with "Scat Crank. . . leaves out quite a bunch here on a forum focused mainly on stock resto. As to which mods are "in" and which are relegated to heresy here is an unclear line and really a learning experience.

FWIW, "Petrobond" is that red clay/oil binder sand you are using. I poured several hundred TONS of iron, bronze, and aluminum castings from <1lb to near 300lbs into petrobond over a 28 year period teaching metal casting.

Be glad you are one of the 'chosen' who has their head together and can measure, think, design, and produce from scratch. Believe me, guys here LIKE to see that stuff, even if it is out of their own personal realm. Reminds me of an old dead guy named HENRY. I would think a thread such as this without thousands of views and a hundred or so posts is more a testament to your abilities and equipment at hand than a lack of interest.

With that said, I'll comment within my expertise and offer just two tiny comments about your castings. 1) Use Al alloy 319, or 356. Don't mix garbage. 2) All those terrible breakouts on the cope (top) surface are caused by the crude flasks. You can't successfully use a wooden 'V' for alignment. Real foundry flasks have iron or steel alignment pins with near zero clearance. That allows a vertical cope draw from the pattern, eliminating sand breakouts. I'm sure you can make some! The cope needs sufficient length to the ears (pin receptors) to prevent any tilting on the draw off the pins. The pins can be V or W shaped, double round (pair) or simple single round like these.

LATE ADD:OMG! I just went back and looked at your pix, #4 you pouring without a full face shield. You do know, one of the disadvantages of oil bond foundry sand like neobond and petrobond is the mold can EXPLODE VIOLENTLY from ignition of HC vapors. Rare, but in 28 years I had at least a dozen severe explosions, one knocked out a door and several windows. I have discarded lots of protective head and body gear with imbedded molten metal damage. Get a hard hat with a full face shield. About the same price as a good white cane with a red tip.

[KR500]

I've not had the pleasure of learning the sand casting process. I thought it would have been easier to cut two full circle pieces on a lathe to accept the seal and then cut them in such a way as to have say 190 -200 degrees of each and them mill or file to exactly half or provide a bit of crush. Enlighten me.

[MikeK]

Originally Posted by KR500

I've not had the pleasure of learning the sand casting process. I thought it would have been easier to cut two full circle pieces on a lathe to accept the seal and then cut them in such a way as to have say 190 -200 degrees of each and them mill or file to exactly half or provide a bit of crush. Enlighten me.

Casting? Here: LINK

[Mike V. Florida]

Originally Posted by MikeK

Casting? Here: LINK

I have interest but not $825.00 worth of interest!

[Mitch//pa]

What you two guys named mike can't sleep. Or are you dreaming about the barn
Go to bed

[MikeK]

Originally Posted by Mitch//pa

What you two guys named mike can't sleep. Or are you dreaming about the barn
Go to bed

zzzzzzzzzz I'm sleep-posting.

[James Rogers]

You do realize,this is a model B, right?

[Chris in CT]

This is for Mike K: Mechanical Engineering 101, second semester: "That which is adjustable will get out of adjustment..."

Chris

[MikeK]

Originally Posted by Chris in CT

This is for Mike K: Mechanical Engineering 101, second semester: "That which is adjustable will get out of adjustment..."

Chris

Yep! Now, where's the wrong tool?

[1931 flamingo]

Interesting post with a lot of followers. Many here have different "talents" and some none. There are probably very few of us here who can do what you're doing, have the space, knowledge, patience, time , money etc and that's part of the high interest. JMO
Paul in CT

[just plain bill]

The in block seal adapters used by the builder of my engines leave a small area outside of the rear main cap that will leak. The builder used a small amount of JB Weld to seal the area. Also used JB Weld to seal the adapter on the outside portion of the block. These ares will leak but they are not on the pressure side. I wonder if the kits mentioned have this problem.

[d.j. moordigian]

Matt,
Thank you for the photos! Like Mike said..." There are not too many here that scratch fabricate mechanical parts "....just some.

[lazlobassett]

I thank you all for the interest and comments and especially good wishes!

Mike,
I especially appreciate your input, I'm a total punter who usually is too dumb to understand things won't work. so just pushes on forward ( usually to impossible sucess) .

I have done casting because of necessity and had no idea it could blow up?

I made new castings Friday night, beefed up the pattern and machined a couple tonight. I am waiting to cut the RMS groove until the new " beige" one arrives. Seems the Scat crank has very little room betwixt the flywheel flange and the oil slinger/whatever it is and the high performance seal is supposed to be thinner.

New pix when it arrives, promis.

the motor is a B with the aformentioned Scat crank, H beam rods, inserts, Fp oiling, Briely A1 cam, vintage ( although thoroughly battered, patched, welded)cragar head, FSI distributor, Burns intake ( have both 1 pot and 2) backed up with a tT-5 lightened flywheel, v8 clutch all in a '31 roadster.

really looking forward to getting this together, hope to escape the NJ winter for Florida in a couple of weeks in it if it all works out...hope hope hope...

cheers!