Girdle

quote:

Worthy of consideration in lieu of four bolt mains?

For all but the MOST extreme Clevelands, most builders will (if honest) tell you it is not really needed. What HP do you intend to shoot for?

Larry

I know drag racers who run very high rpm with two bolt mains, but road racing puts a lot more strain on a motor than drag racing. It takes a lot of abuse to make the two bolt caps walk in their registers when they are tightened properly, but I like to build-in a margin of safety (some people call that over-building). A naturally aspirated motor rev-limited at 6000 rpm doesn't need the girdle. If the rev-limit is 7000 rpm or higher, and you planned to run in the higher rpm range full time (not just a blast on a freeway on-ramp), then I would install the girdle.

The part of the girdle that bends around the oil pump will interfere with the oil pan. What I've done in the past is remove that part of the girdle with a hack saw. The alternative is to bang the pan out with a ball peen hammer and hope nobody looks under your car.

-G

Larry, I'd like around 400 hp at the rear wheels. I want to do the marque proud at club track events and still drive her there and back home again.

George, should the girdle be torqued in place before crankshaft bearing alignment is checked and/or corrected?

quote:

I'd like around 400 hp at the rear wheels

For that HP, in a street Pantera, you normally would not need a girdle.

For a LOT of track time, and following with George's advice, unless you somehow plan to run road races in the 6000+ rpm range, I don't think he would advise a girdle, either.

George?

Larry

Well, for a bit less than $200, actually $140 since it comes with the $60 ARP main bearing studs I was planning on using anyway, it seems like cheap enough insurance.

Some day I might want to swap that 6000 rpm limiter chip for something higher?

When I was building my 460 I was looking for a high nodularity 429 4 bolt main block. After I found the motor I wanted I was told I could hve used a 'thick web' block and a girdle. These guys get 1000HP out of normally aspirated 460s

So I guess, if you have a strong block go for the insurance and use the girdle.

Denis

quote:

Originally posted by larryw:
George, should the girdle be torqued in place before crankshaft bearing alignment is checked and/or corrected?

My preference would be to align-hone it with the girdle in place.

quote:

Originally posted by LF - TP 2511:
... unless you somehow plan to run road races in the 6000+ rpm range, I don't think he would advise a girdle, either ... George?

I'd rather provide guidelines and let people form their own opinions. It won't hurt anything to install the girdle, even if its not needed. Larry's point about deciding to run the motor harder in the future is a valid one. Girdles are very common with small block Chevys and Windsors, and although the Cleveland lower end is much beefier, Ford engineers specified 4 bolt mains for the 351 Cobra Jet and Boss 351 for a reason, not to waste Ford's money.

-G

Larry W....that windage tray is a nice find. I have the Armando pan and have been looking at windage trays. That one bolts to the pan rails and not the main caps like the Milodon version and others, which I like better. I would rather just leave the main caps alone.

I wonder how many issues you run into with making the gasket seal...it looks like there are gaps in the metal instead of one continuous piece running along the pan rail. How would you seal that? I know you have to use two sets of gaskets and probably a lot of gasket sealer?

quote:

Originally posted by Tom@Seal Beach:
... I have the Armando pan and have been looking at windage trays ...

Tom, the Armando pan has a windage tray built-in.

-G

Thanks G! I've forgotten if the baffling ran the whole length of the pan. It's still in the box and as I recalled it just served as baffling for keeping the erl covering the pump pickup? I'll have to look at it again. Just saved me some $$$ to throw somewhere else on the car. Thanks Much.

Is that similar to what I have sticking through my valve covers? Other owner told me would do 6,500 RPM all day, although I am pretty conservative with gum shoe always in the bushes here in CA.

Similar intent. Lower end main bearing support in my case, top end rocker stud support in yours.

Damn I wish my engine compartment looked that GOOD!!! (sorry for swearing George). I get depressed everytime I see something that nice...its so much work to get it to that point. Every stinkin part has been messaged. Seriously I'm looking at the photo and can't find anything that needs work. Very nice Does 200!

Jan, where did your headers come from?

quote:

Originally posted by larryw:
Jan, where did your headers come from?

Not sure where the headers came from. Kuntz & Company in Arkansas did the engine, so maybe they got the headers for it.

Larry

here's where I recommend cutting the girdle in order to prevent interference with the oil pan.

-G

quote:

Originally posted by DOES 200:
Is that similar to what I have sticking through my valve covers? Other owner told me would do 6,500 RPM all day.....

There are two types of 351-C 'girdles': one is a massive metal plate inside the oil pan that reinforces the crankshaft's main bearing caps while the other is a set of bars that clamp all the rocker studs together under the rocker covers, reinforcing them. Your special SVO covers are much thicker than normal, with special long rocker studs extended thru the thick cover top. The effect is the same as a girdle inside, but they weren't popular with go-fasters 'cause it's much less convenient to get inside the covers & adjust valve lash with 8 bolts plus 8 stud-nuts to r & r each time- on each head. If you ever find any, pick up as many of the spare stud-seals as you can find- each top acorn nut has (or had) a conical washer and a dead-soft copper seal under it to prevent oil leaks. They've all been unavailable from Ford/SVO for decades.

Jack,

I can't see how spinning those acorn nuts off, then the eight rocker cover screws, popping off the rocker cover and having your rockers staring back at you ready to adjust is any less convenient than removing the rocker cover and then removing the fasteners required to split a two piece girdle in half that clamps a bunch of special adjuster nuts. Am I missing something? Perhaps those SVO covers are just rare, not a weak design?

George,

Is "cap walk" in a two bolt main engine at stressful RPMs a side to side or a fore and aft sliding movement?

Could it be restrained by, say, short hardened .250" dia. dowels fitted into holes drilled into the cap and block in lieu of four bolt caps? They could be positioned where the outer bolts of a four bolt cap would usually go and, being much smaller than a 3/8" bolt, would not compromise the two bolt caps(?).

An align bore would probably be a good idea afterward.

Or is it actually the cap lifting away from the block due the elasticity of the two bolts (or studs) stretching and recovering that the two outboard bolts of a four bolt cap reinforce?

The forces acting upon main bearing caps stretch them and twist them. When inspecting the caps for cap-walking it is identified by a burnished look to the mating surface of the caps. To answer your question, cap walk is neither fore aft or side to side, its circular around the cap bolts.

The caps in a 351C should fit very tightly in the block, it should be difficult to remove them even after the bolts are removed. That interference fit in the cap registers is a big part of their stability. The outboard bolts of a four bolt block add to that stability, its much harder for a 4 bolt cap to twist within the register. But the outboard bolts don't add much in the way of clamping force, the inboard bolts do most of the clamping.

Another part of the stability of the 351C lower end is simply the "beefiness" of the caps themselves. They are thick and bulky and more difficult to twist or stretch than a smaller cap would be. Look at the picture of the girdle, you'll realize that besides tying all the caps together to resist twisting, it also acts as a steel strap to help prevent stretch. By resisting cap twisting and stretching the girdle reduces the forces that result in "cap walk".

Denny Wydendorf has used a two bolt block in his drag race Mustang. He did as you suggest, he installed pins in the outboard location of the two bolt caps where the outer bolts would be located in the four bolt main caps. Denny launches at 8800 rpm and shifts at 10,000 rpm.

rock and roll

-G

quote:

Is "cap walk" in a two bolt main engine at stressful RPMs a side to side or a fore and aft sliding movement?

Could it be restrained by, say, short hardened .250" dia. dowels fitted into holes drilled into the cap and block in lieu of four bolt caps? They could be positioned where the outer bolts of a four bolt cap would usually go and, being much smaller than a 3/8" bolt, would not compromise the two bolt caps(?)

That works and is about the only way to reinforce a 2-bolt Cleveland main cap, since there isn't enough meat on the outer ends to drill for the extra small bolts. FWIW, my Fontana aluminum race block uses two long 1/2" studs, two angled allen bolts AND two 1/4" dowels in each steel main cap, to harness 800+ bhp. These caps aren't easy to remove even with the crank out!