getmygoat

Hi all,

I've read various threads on this forum about oil seals... e.g. use a Ford or AMC seal, etc. However, what doesn't seem to be fully addressed is what to do if the crank will maintain the factory serrations in the seal area? Are the non-rope seals generally compatible with these serrations? Word on the street is that these serrations can tear up the neoprene seals and really its the rope seal that can tolerate them. I am planning an in-car rear seal replacement ('76 350) so the crank will be in place and original w/ serrations. (I've already read the serrations can be polished with emery cloth but that seems unlikely to me sitting here in my arm chair at least).

I think the neoprene type seal will be much easier to feed into the block portion of the seal with the crank in place, but if it just gets torn up after 500 miles or whatever it would be pointless to use it. I asked BOP engineering and they recommended their viton seal ($45) and indicated they have run it with factory crank serrations with no problems.

I've also read about the "sneaky pete" which appears to be designed to pull a rope seal through the block portion of the seal recess area - if I can find a rope seal with impregnated graphite that fits the Olds 350.

Hoping to get other opinions/experience regarding this topic. Thoughts? - Thanks much!

olds 307 and 403

Installing is easy, getting out, not so much. You have to drop the pan and possibly loosen the main caps to get out the old one. I used the AMC and Ford 292 rubber seals, worked fine with factory serations.

getmygoat

Hey thanks for your response. I was under the car today (working on installing a Trans-go "repair" kit and resealing most of the trans (except front pump). Anyway, I'm generally familiar with the process of getting to the seal with engine in car (bought a service manual a while back). Looks like easier than Pontiac which requires engine out.

I'm hoping to only remove the rear most bearing cap and not mess with the rest, just to reduce risk of me screwing up bearing clearances, etc. Hopefully its possible. I've read you can use needle nose to grab the old rope seal and pull it out (not easily but possible).

Sugar Bear

Using a soft metal rod to avoid scratching the crank you could push the opposite side whilst pulling the other side. Olds had a special tool to repack the upper half tighter. Did a few decades ago on Olds diesels, it worked. Due to the age of the rope in there I wouldn't recommend packing it tighter vs replacing.

oddball

Polishing the serrations is not strictly required. "It Should Just Work", but that's a tough one to trust when talking about an in-car replacement.

OLDSter Ralph

Something I thought I read on here from one of the learned folks.....stated that the lips of the Ford/AMC seal lips did not run on the serrated area. Perhaps that person will pop up and refresh our memory.

BillK

I saw that too but I dont think it is correct. I am putting one together right now and the seal most definitely runs on the serrations. I usually have the crank out of the engine and I have always polished the serrated part. Have not had any problems with it.

getmygoat

Thanks for all the responses - at this point its sounding like maybe an in-car replacement of the seal is not possible with the Olds 350 - since an impregnated graphite seal doesn't seem to be available, and use of a lip seal with the stock crank is asking for trouble.

Seems like an impregnated graphite seal should work but its specifically listed for other Olds motors but not the 350, so there must be some difference.

oddball

The lip seal runs on the edge of the serrations, not in the middle like the rope seal. But it still touches. The serrations are not a precision part of the crank so I bet there's variations on where, precisely, they start and stop on various cranks, so maybe on some they didn't go as deep so the lip seal manages to miss them.
Viton is just a different rubber. Same basic seal.

As for the graphite rope, "Big block" Olds use a 3" main, while the "small block" use a 2.5" main so formed seals are different. A rope for a big block would be fine as you're just cutting off the excess anyway.

Rope seals worked for decades. So if you can get it replaced then great! If you can't get the new rope installed then installing a lip seal in the car is certainly a good fall-back position.

getmygoat

Thanks for that insight !- do you know for sure if the diameter of the seal (i.e. seal diameter or "width" not crank diameter) is the same for big and small block? Of course if the big block seal width/diameter is larger - it could affect bearing clearance in a worse case scenario - which of course I would want to avoid.

joe_padavano

Your question is unclear. "Seal diameter" is the diameter of the journal that the seal rides on. That's 2.5" for an SBO, 3.0" for a BBO (and diesel). Neither of these have anything to do with bearing clearance.

olds 307 and 403

Many of us have used the 292 and AMC seal without issue. The AMC is a tighter fit than the 292 seal. A rubber or neoprene seal is massively easier to install in car than a rope seal.

getmygoat

Just to ensure clarity, have you used them with a factory serrated crank? (not polished). - thanks!

getmygoat

Well, as I tried to clarify in that post... If the groove for the seal in the small block is smaller (e.g. narrower, less deep, etc), then the big block seal might not "fit down into" the groove well, and then "get in the way" when tightening the bearing cap, thus potentially affecting bearing clearance. Just being paranoid to avoid potential problems.

I got a response from the "best gasket" folks, and they indicated their 6382S (graphite impregnated rope ) seal is "narrow groove" and will work for an Olds 350.

olds 307 and 403

Yes, multiple motors. As far as I know, my current rebuilt 350 they weren't modified. I actually wasn't worried about it because it hasn't been an issue on stock 350 and 403 cranks.

joe_padavano

You can believe whatever you want from vendors. The fact remains that many, MANY people here have been using the Ford 429/460 seal on the BBO and the Ford Y-block seal on the SBO with zero problems. I've been doing it for nearly 50 years now. Nor have I ever done anything to the serrations on the journal. The serrations are intended to pump oil away from the seal as the crank spins, reducing the potential for seepage. Don't make this harder than it is.

rickw30

^ x2

oddball

I'm 90% certain that the seal groove width and depth is the same on 3" main and 2.5" main caps, with the obvious difference in diameter. So a rope seal for one is fine for the other - there's just extra length to cut off. But they're extra long anyway because the install procedure is to pack it in and trim to length. No idea what the vendor was talking about with "narrow groove".

As for the lip seals, some of them have extra material on the back that can make it squeeze extra tight on the crank - the Gospel According To Trovato talks about trimming the back on some of the seals. Same thing though - it's not strictly necessary.

BillK

I have done at least 5 and had no problems. When I did my Wife's 307 I decided to try a seal from BOP and to be honest with you it did not fit to my liking so I used the Fel Pro one for the Y-block instead. It has not leaked a drop in almost 4 years now.

As far as the serrations go Chrysler had cranks with serrations on their big blocks and used a rubber seal with them from the factory so I dont think it is an issue.

getmygoat

Thanks all for your input! Definitely no substitute for hands-on experience. I'll post some pics once I get started on this project in the next couple weeks.

Thanks again!

oddball

If you go with the lip seal just make certain to face the lip the correct direction!!

getmygoat

Hey all, started into this project today. Got the front of engine down to harmonic balancer. Waiting on a 1 1/8 impact socket before pulling timing cover. Also tried to remove cross-over pipe. Got all four bolts out (broke one off in manifold :-(.... but the cross over pipe is "stuck" to the manifolds? Is there a trick to getting this off? Tried beating on it with a rubber hammer no luck. Thanks (No heat available).

Sugar Bear

Other than doses of penetrating oil and some impact/strikes, not many options without heat, Many members prefer 50/50 ATF and acetone for the penetrant. it'll smoke from the penetrant on start up.

getmygoat

Thanks. I used penetrating oil on the bolts but hadn't considered that the flange might need it also. Will try that. thanks

BackInTheGame

Like SugarBear says, also give it a few good, solid hammer raps when you apply the penetrent. That will help setup a vibration to help the flud to wick into the voids, in addtion to helping break loose any rust. Do this for a few days, a couple of times per day.

getmygoat

Thanks for your help all - I got the cross over pipe down with some PB blaster and rubber hammer. Removed starter and engine mount bolts. Ready to jack up the motor but I noticed the engine mounts obscure some of the pan bolts - so it looks like the mounts need to be removed from the block to get the oil pan off. This makes it more difficult to secure the engine in a raised position. I know the service manual says to jack from the balancer but I really don't want to do that because 1) I don't want to risk my OEM balancer rubber - which appears to be in good condition and 2) I don't want to risk damage to the crankshaft. So I was planning to maybe jack via 2x4 running vertical to exhaust manifolds (or block where starter mounts?)... but was hoping to secure it by placing wood between engine and frame mounts, but if I need to remove engine mount then that's no longer an option.

Any thoughts on this? How to secure a lifted engine with no motor mounts and not via pan or balancer? Seems like a challenge. I suppose I could jack one side, remove mount, remove previously blocked pan bolts, reattach mount, lower engine, etc.

Sugar Bear

Support/hang it from the top.

joe_padavano

At which point you're again only six bellhousing bolts (plus the torque converter) away from just pulling the motor and doing it the easy way.

Sugar Bear

Probably would be best to remove the hood?

Vintage Chief

I supported it and hung it from the top of my engine hoist/lift. I slid an engine lift/hoist into the engine bay with the hood installed. I thought it was pretty easy. I'm not 100% detaching is necessarily the easy way - it's one way. Of course, w/ my svelte figure I find it easy to maneuver under the car.

getmygoat

Yeah I'm starting to think I need to buy a harbor freight crane which I was trying to avoid. These used to be half the price they are now. Even if I just use it to lift the engine in position, school of hard knocks says do it that way instead of trying to Jerry rig it from below.

Vintage Chief

I found this to be a decent enough hoist/lift w/o braking the bank & has a small footprint when storing.

ACDelco 4000 Lbs. Engine Hoist

getmygoat

Looks like a deal but pick up not available and delivery not available.

Vintage Chief

Call your local O'Reilly.

Vintage Chief

Harbor Freight has a Pittsburgh 1 ton. One ton is all you need anyways.
https://www.harborfreight.com/1-ton-...MjQyLjk5In0%3D

67OAI

I used a length of heavy duty unistrut long enough to span across the engine compartment, lag bolts to attach the unistrut to scrap pieces of 2X4 lumber to distribute the weight and keep the metal of the unistrut off the fenders. A length of 1/2" all thread, coupling nut, various pieces of unistrut hardware, etc. to make an engine support in lieu of an engine hoist.

oddball

Just note with most engine hoists that the beam is every so slightly too short, at least with something like a '72 Cutlass with the bumper and grills in place. I would usually have to drop the grills and bumper and have the hoist wedged right up against the core support to get far enough back.
The local party/equipment rental place has "knock down" Blue Bird engine hoists for rent. I really like using those, but of course most of their hydraulic cylinders leak.

getmygoat

I'm in - but can't get the bearing cap off - been hitting it with a rubber hammer but no luck so far. Any tips/tricks? Also do these look like factory pistons? They are almost a cream color. One is stamped "5" but its in the #1 hole. The connecting rod bolts are like 12 point or something. Is that also factory olds?

Thanks for any insights!

getmygoat

Sorry one more question.... does anyone have a strong preference for the Y-block (bs6141) or AMC (BS40612) seal? I've read the AMC seal is "tighter" which sounds like a good thing generally. Thanks again.

oddball

The #5 cap has dowel pins. Use its bolts as levers in their holes and hit it forward and backward to wiggle it free. Side to side is harder in tight confines.

Either seal will work, just have different bits to trim off or throw away.