Author Topic: Talk me out of it and rear main seal ?  (Read 460 times)

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RustyCrankshaft

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Talk me out of it and rear main seal ?
« on: December 07, 2018, 12:36:40 PM »
The brown and white camper special I posted in another section has a pretty low mile 360 that is in good shape but has some issues I don't want to mess with right now and it still drives, sort of. Going to throw a 390 in it so the truck is in an undriveable state for the shortest time possible. I've got a 4.110 390 that the block was still good on, so I lightly honed it on the Sunnen and going to run it (it's not perfect but its serviceable). It's going back together with low buck stuff mostly, hyper pistons, etc. Has C1AE heads, running those because they already had hard seats, new valves, decks were flat. I cleaned them up, freshened up the valve job, PC seals, and prepped them for the appropriate springs for the hyd roller Brent had ground for me,227/235 @ .050", .565"/.587", with a 111 LSA. It's between 9.5 and 10 to 1 (I need to re CC the heads to verify but should be 9.7).

This truck will be the new shop truck, isn't really going to be a work truck. Mostly fetching parts, might pull a small trailer but doubtful. The truck is a 73 F250 Camper Special (pics posted in the projects forum), C6, 4.10's.

So after that long winded story....I've got a couple intakes laying around I've collected over the years and I'm trying to talk myself out of buying an RPM. I've got an iron S, which I'd like to avoid because my back hurts just looking at it. I've also got 2 Performer 390's (because they got swapped for better manifolds already).

I think the RPM would be a better choice, but I'm trying to convince myself it isn't 450 bucks better. Since this won't really tow much, if anything, and with 4.10's and stock 16" tires with the C6 it spends most of it's life above 2500. But it's also sort of on the fence. If it was build strictly as a work truck I'd put the S on it.

Also, what is the prefered method for the side seals on the rear main cap? The last time I went this far into an FE I was in my teens and the leather seals (out of production by then I'm sure but still tons laying around) swelled and sealed instantly once oil hit them. A lot of the FE's I see running around here seem pretty wet, especially rear main seeps/leaks. Skim coat of RTV on the neoprene? Someone offer a better quality seal strip?

cammerfe

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Re: Talk me out of it and rear main seal ?
« Reply #1 on: December 07, 2018, 01:46:54 PM »
Squirt 'em full of 'The Right Stuff'.

KS

RJP

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Re: Talk me out of it and rear main seal ?
« Reply #2 on: December 07, 2018, 03:32:46 PM »
Don't discount the "S" manifold just yet. My 69 2WD F-250 is similar to yours, 390, C6, 3.73 gears. I took off a untouched Streetmaster and replaced with a iron S manifold. After lowering it on with a cherry picker and running it with no other changes the S manifold yield about 1.5 mpg increase in fuel mileage, ran smoother from idle to a self imposed redline of about 4K rpms. It also was more pleasant to drive as it had a increase of low end torque without affecting the midrange. Overall the S manifold was a win-win over the Streetmaster....I keep the cherry picker handy though. ;)

RustyCrankshaft

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Re: Talk me out of it and rear main seal ?
« Reply #3 on: December 07, 2018, 04:41:12 PM »
The thought had crossed my mind, but I'm generally not a fan of slathering stuff full of RTV, but if no one makes a decent seal these days I'm not opposed to it!

I haven't really discounted the S, just wasn't my first choice due to weight. I just don't have much experience with the Performer 390 to really give it an honest comparison to the S. Only Performer 390's I've had came on trucks and always with a 360, so with the intake, headers, and even a little cam they were probably 225hp engines.

The S and P390 are pretty similar in Jays book. The RPM isn't giving much at 3k vs the S, T or P390, but sure pickups up a lot at RPM. This thing won't see any racing, just going to haul parts and scare Chevy owners getting a ride home from the shop. Still, even being a budget (ok, cheap) build I don't want to leave a bunch on the table either.

There's a Holley SD on fleabay but guy wants 400 bucks for it.

Tempted to just throw the P390 on it because it's sitting here and swap it later when something better comes along and it won't require me to road the Grove down here to lift the S off after it's in the truck LoL

RJP

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Re: Talk me out of it and rear main seal ?
« Reply #4 on: December 07, 2018, 06:57:13 PM »
If you have the Perf. 390 then by all means use it. It is a decent street manifold, [I ran one for years on a street/hiway 428 /C6] cruiser. If it were a matter of having to buy a Perf. 390 vs having the S manifold already in your possession I'd save the money and cherry pick the "S" manifold on to the truck and be done with it.

blykins

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Re: Talk me out of it and rear main seal ?
« Reply #5 on: December 08, 2018, 07:16:46 AM »
FWIW, I've always used the side seals/nails in the Felpro rear main seal pack.  I shaped them if necessary, then lubed with silicone and drove them in with the nails. 

However, on my dyno mule, I skipped the side seals and nails and just shot the cavities full of the Dow Corning 732 silicone that I use.  Stuck the nose of the caulking gun tube down in the hole and started packing it in.  It smooshed out the front side and rear sides both, so I just smoothed it up with my finger and went with it.  No leaks on the dyno, absolutely dry as a bone.

I will probably start implementing that method from here on out.  Some of the aftermarket blocks are a pain in the hindend to get the side seals shaped and narrowed down so that they fit in the holes.
Brent Lykins
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RustyCrankshaft

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Re: Talk me out of it and rear main seal ?
« Reply #6 on: December 08, 2018, 07:26:35 AM »
I guess I'll try cramming the RTV in them! Working on diesels to pay the bills I have a LOT of 599 Grey because you can't keep a modern Cummins from leaking like a screen door on a submarine without it. Loctite even has these needle nose nozzles for the caulk tubes of RTV that are kinda handy.

Despite wanting something nicer, I've sorta talked myself into running the P390 for now because it's sitting here. I'll see if between now and when the intake goes on something nicers comes along.

My427stang

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Re: Talk me out of it and rear main seal ?
« Reply #7 on: December 08, 2018, 09:42:11 AM »
I like the side seals as Brent noted, fit them, slather them up, stick some sealer in the hole first, push them in by hand, then put the nails behind them.

However, RTV has grown up since the smelly blue Permatex.  I would expect that a newer adhesive type sealer would work great on it's own.

As far as the Performer 390, they run great, they are down on power, but I think for your use it'll be a happy truck.  If you wanted to play around you could round off the plenum divider and add a 1 inch open spacer.  Not sure it's worth it though if you just want a happy torquey truck.  I'd likely just run the P390 and recurve the distributor.

BTW, it will take either some thinking to fit headers, the C1 ports are .250 higher than most truck headers.  If you run manifolds no big deal, of course if you run manifolds, no use worrying about the P390 either :)
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Ross

- 70 Fastback Mustang, 489 cid FE, Victor, SEFI, Erson SFT cam, TKO-600 5 speed, 4.11 9 inch.
- 71 F100 shortbed 4x4, 445 cid FE, headers, RPM , 1000 Holley HP, Bullet SFT cam, 4 speed

RustyCrankshaft

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Re: Talk me out of it and rear main seal ?
« Reply #8 on: December 08, 2018, 04:18:00 PM »
I think I'm going to see how well the side seals fit in the gasket kit I've got. If I don't like them I'll just try going all RTV, if they fit half way decent dress them with RTV and install them.

RTV has definitely improved since it's beginning. The grey 599 stuff I use a lot of at work and we never have issues with it, unless some schmuck uses an entire caulk tube full on a single pan gasket.

The truck has a set of some unknown long tubes on it, which I suspect are probably headmans. Everything that bolted on this truck happened with the second owner who I got the truck from and so it would have been around 99 (think it got parked in 2000 or so) which is why I suspect headman. They're pretty rusty. I think FPA, which as far as I know are still built by Stan's Headers, I think has a set of headers that fit. Stan's is within driving distance for me so I can go see the flange and make sure it'll work.

I knew that would be an issue, but I figure the heads being fresh is worth messing with the heads rather than porting and going thru D2's. Because at that point I would have just bot a set of stock Edelbrock's. So I figure I saved myself 1400 bucks with the C1's. Well, 700 after the new headers. I've never owned an FE powered truck that didn't immediately crack the manifolds, so not going back with manifolds.

It all sounded good in my head. If it wasn't for bad luck I wouldn't have any, so I'm sure what I've really done is set myself up so once the engine is sitting in the truck I'll figure out no one makes a set of headers that fits the taller exh port in an automatic pickup with power steering and spend a month building headers while the truck plugs up a hoist in the shop and something shiney is sitting in the rain.

turbohunter

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Re: Talk me out of it and rear main seal ?
« Reply #9 on: December 08, 2018, 04:55:12 PM »
I’ll chime in on the Performer 390.
I run one on my ‘74 short bed 4x. For me it’s a great truck manifold. Yes it’s down on hp but dang if it doesn’t make up for it in grunt. My truck engine is a 400hp 500ft lb deal.
I can lug the crap out of it on hills and slow wheeling. I love the thing.
Would I put it on a street deal, no, but for a truck it’s cool.




« Last Edit: December 08, 2018, 05:39:32 PM by turbohunter »
Marc
'74 F100 4x short box 441FE
'61 F100 292Y
'67 Fairlane 427+ FE TBB (to be built yet)
'66 Mustang 440 FE (428cj block) Being built
'66 Q code Country Squire wagon


RustyCrankshaft

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Re: Talk me out of it and rear main seal ?
« Reply #10 on: December 08, 2018, 05:27:05 PM »
Ok, you guys talked me into. I'll run the P390 on it! And here I thought you guys would be talking me into spending more money!

If anyone is interested, Sanderson just sent me a reply email (on a Saturday no less) that the FF427 headers have a flange that will work with the higher exhaust port. I'm not sure if I want a header that short for this, but Sanderson's are well built for the money. I have a set on the 73 F350 460 and they haven't leaked and fit nicely.

Still might give Stan's a call and see if they're tri-y's will work.

My427stang

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Re: Talk me out of it and rear main seal ?
« Reply #11 on: December 08, 2018, 05:50:11 PM »
BTW - FPA can make you a header for either flange

Also, I have never seen a side seal fit nicely.  I use a sanding block with 80 grit and rub the side seal on it until it slips in, then I coat it with sealer and slide it in.
---------------------------------
Ross

- 70 Fastback Mustang, 489 cid FE, Victor, SEFI, Erson SFT cam, TKO-600 5 speed, 4.11 9 inch.
- 71 F100 shortbed 4x4, 445 cid FE, headers, RPM , 1000 Holley HP, Bullet SFT cam, 4 speed

rcodecj

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Re: Talk me out of it and rear main seal ?
« Reply #12 on: December 08, 2018, 06:02:11 PM »

Also, I have never seen a side seal fit nicely.  I use a sanding block with 80 grit and rub the side seal on it until it slips in, then I coat it with sealer and slide it in.

This is the truth. I bought a bunch of them and they varied all over the place in width. I used a wider measured one and sanded it until it fit nicely.
Mine had to be tapped in after sanding but not hammered in hard or anything like that, no leaks so far.