392 Hemi / 4 Bolt Mains Vs. Stud Girdle

Reading alot lately attempting to determine what is best, 4 bolt main caps or a full stud girdle on a 392 hemi, built for serious HP ?

I have 4 bolt mains in my race motor now, however; trying to determine which is best for "serious" HP.....

 

I was at I think it was Pomona a few years back and the Winged express had broke the bottom end of Their 392 and it had four bolt mains (splayed type) that Joe Reath sold a lot of. Joe also sold a girdle that covered the center three main caps. If your gonna go with real serious HP you would be better with a full girdle which tied all the mains together and have machined main caps that had full contact with the girdle (not the kind that uses the stock caps with spacers that slip over the studs) and would have the proper crush when torqued to spec's. This would not only keep the caps from moving it would help the block resist twisting. Unfortunately I don't know of anyone that makes one of these so it would probably be a very expensive custom piece.

 

Of course I am a bit bias towards the girdle.
Here is what Dan Miller and Gene Adams have to say about it.

Tom Waters Girdle

by dan miller » 13 Nov 2009 10:17
We were having trouble with the front main cap moving around on our 354 EMC early hemi. The engine is partially filled, cryo treated, and has 4 bolt splayed main caps on the center three mains.

We had no issues up to about 550 horsepower. We noticed metal transfer on the front main cap at around 575 horsepower, and it started to become an issue at 600 horsepower. We installed a Tom Waters girdle and made 121 pulls, many over 650 horsepower. Upon tear down, we observed that the front main is now solid. Zero movement/issues.

We also installed one of Tom's girdles on our Junior Fueler, about 850 or so horsepower. At these power levels, main cap movement is a fact of life, and one just has to live with it. We only have about ten passes on it (and haven't torn it down yet), so it's probably too early to tell, but I'll advise when we see something. It might not cure things, but I'm betting that it will be of significant help.

A very nice product. Inexpensive, very high quality, came with all parts necessary, installed easily - a true bolt on. I highly recommend it.

Danny

And the update:

We run the JrFueler @ approaching 900 hp, and have zero issues. The mains walk around a little, but much less with your girdle. We have about 40 passes on a new block, and there is main cap movement, but significantly less than without your girdle. I'll try to remember snapping a pix of it the next time we have it apart.

Thanks again for supplying us the two girdles. One is on the JrFueler, and the other is on the EMC engine.

Danny

IMO, having a girdle that rest across the main caps does nothing. And why would you install thicker main caps and then mill them back down.....in the weakest area...over the crank centerline?
Cap walk is not a product of the main caps flexing in the center, nor is it a product of block movement. It is due to harmonics and/or detonation. Cracked main webs are not from the block flexing. They are from harmonics and detonation.

 

TR WATERS : I have a question. In the pic above, obviously they are using your stud girdle with ARP studs, however; it is hard to tell from the picture as it will not increase in size on my computer for some reason, are the center three main caps, splayed 4 bolt mains ?

Second, will this clear a STEFS oil pan with baffle, etc ?

Thanks, Neil....

P.S.: What machine work has to be done for the Girdle to rest on the bottom of the main caps as well ?

 

Didn't know that, excellent......

 

I have seen straps on FH's and Jimmy 302's, however; trying to figure out what is best for 800 HP.....

Interesting on the pipe plug in the rear main....

 

The engine pictured is the EMC shortblock of Gene Adams. It uses 4 bolt center caps.

I am not going to get into an arguement....but.....adding a strap to the top of a main cap does nothing for capwalk. In fact, you now have added over an inch length to the bolts or studs. Will a strap add strength to the main cap? Very marginal. Maybe a bit more with a set screw in the center. It is "old school....we have nothing better" technology.

A girdle such as mine does not add strength to the caps. Nor does it add any strength to the block. But it does add rigidity to the 5 main caps.

Candy-Man..feel free to email me at [email protected]

Next subject

 

There are you happy keyboard expert, I deleted everything, the only thing you said that made any sense is that your not gonna argue with me. No one said a fucking thing about a cap strap stopping cap walk. Are you insane. Lets see, I have built race engines that have won Nascar, championships in NHRA, IHRA, APBA, and your gonna argue with me. I retired at 50, live in a half million dollar home on the beach in Florida, all from building race engines. Pick a arguement with someone who will actually believe your bullshit. King of girdles, what a fuckin joke. Oh yea, when you put a girdle on that doesnt add to the length of the studs, what are you drunk or something, SOBER UP, GO TO REHAB, GET A DEGREE IN ENGINEERING, WIN A FEW HUNDRED RACES, and even then, dont call me, call someone who's dumb enough to listen to your bullshit. Ive taken a lot of shit on this forum from you fuckin know it alls, hows it feel, cause Ive backed down for the last fuckin time. You read in a magazine about detonation and harmonics, ever do a comprehensive study on harmonics, I have.

 

...wow!...

OK, I'll add my 2 cents.
We have built blown 392's with stock caps and studs and no issues at around 1000 hp. We have also machined billet caps to add some bulk and it made the customer feel good but I'm not convinced it made any real world difference.
I do not personally like the splayed caps with the small screws going into the water jacket.

To each his own.

.

 

Sorry fella's, not trying to cause any issues....

I'm trying to determine the best method to strengthen the bottom end of a 392 hemi with 800 HP as there are three different skools of thought out there, some of which I do not understand.....

I understand 'keyboard rage' as I wanted to go through the computer a while ago regarding some very inappropriate comments made here on the HAMB by a fellow Canuck who though he was being Kool, while he offended just about half of the board....

Thanks to all, I appreciate the advise......

 

I would like to hear more on the doweling. Knowing nothing about this first hand - my first thought would be to wonder why not sleeve dowel it around the bolts like the rear main. Seems like it'd be easier to set up/machine.

Also can someone expand on the "pipe plug" comment???

Please.

 

Jacin: I was thinking the same, regarding the sleeve around the main bolts/studs but issues occurred.......

I may have this wrong, however; I believe the pipeplug would be installed in the rear main when using a dry sump....

 

A bit on the harsh side. I guess we all have our own thoughts on what works the best. Now lets keep posting.

 

Calm down everyone.....I'm a soon-to-be-retired race motor builder in the services of several big teams....lets decompress....we're not fighting with the dumb NHRA or NASCAR rule mediators or officials during a motor teardown because someone protested us....
We all know here the advantages of stud girdles and how they're suppossed to be made.
Buy what makes the issues you have go away or machine out your own so you don't have flex or movement....no need for all thsi other quick tempered stuff....

Personally....I'm with 73RR....I prefer the larger caps, and crossdrill the side of the blocks to stabilize things. This ties everything together....just my 2 pecos....

 

I was under the impression that a full girdle ties the caps together, then it connects to the block solidly with heavy metal.

The one in the photo is a halo.

Big difference between the two

 

Whats a water jacket?

 

The old full girdles were a pain in the ... but were good In my opinion . Lippy

 

These are pictures I have had for some time. No idea who made it. I think its a great idea, but would be very costly to produce...either in cast or billet. I think that one core could be made to be machined for either a low or high deck.

The problem with this type is the same as with a Donovan. Changing main bearings. Not a concern for the most of us, but probably the reason this idea never took off.

All of these ideas, including mine, are a band-aid to help a block made to produce 300 hp survive 600 or more hp.

Now....when the new aluminum early hemi block is finished....some of these problem will be addressed.

 

They were better than nothing.....lippy....you know the old diggers and the waterjackets thing.....don't put anything in there you wouldn't want in your pan!!!

 

Absolutely. If money was no object I would never run an iron block on high dosages again. I am simply amazed the punishment some of these old blocks that use to haul the family to church can handle the detonation and abuse they do. On gasoline or inj alky I think they are fine. Four bolt caps, fill the block , stud it and go. But on juice detonation is a killer. And I don't mean 20% either. . I would just go to a Donovan or Big E's blocks. TR, you contemplating a block? Lippy.

 

Hey TR,

I could be wrong, my eyes are not what they used to be, but is that girdle machined to accept another main bearing at the rear cap? It sort of looks like two bearing inserts there....



David

 

If you look close, you'll see that someone has the #1 bearing in where the rear main seal is.

I am not doing a block, but have it on pretty good authority that one is in the works. These things always take lots of time and even more money.

 

Ah, I see it now. Thanks!

So someone is working on an aluminum block... I hope they go with a 4.25" bore. There is just enough room. Combine that with a 5/8" arm and you'll get something close to 513 cubic inches.

David

 

Not all '92 blocks are equal according to some , the "A-1" is supposed to be best but even core shift can happen. I know in the case of "The Wing" ,Mousie, Willie and now Mike have had some blocks that survived 80+ runs and yet others that split wide open between the center 3 holes(Lots of Bondo to fix this one,kid from Jimmie Boyd !) Basically the head was holding the block from total seperation. Yeah ,Youngblood Did an excellent forgery of a Kern County Coroners Death Certificate on that bullet! Oh yeah , that one had splayed caps and a grand in machine work. So the opportunity came from " The Cowboy" for a fresh Donnie , girdle and Sonny crank but it just doens't have the "thump" that an iron motor has. Nitro will make a very humble person of you! Good luck CandyMan!

 

Can anybody tell me the average cost of the machine work to adapt a 392 hemi for 4 bolt mains?

 

I would say somewhere in the $350.00 range. This is to install the caps and line bore.

 

Care to divulge your plans?
There are some of us who don't have much use for the splayed bolts...

.

 

Hollow dowels as used in some OEM and Carrillo rods are useful precisely locating a bearing cap at assembly. And allowing more-or-less standard bolts, free of cap locating features.
http://www.jalopyjournal.com/forum/attachment.php?attachmentid=1557853&d=1328654838

Adequately sized Solid dowels are stronger and stiffer, But the clamping force from properly tightened bolts is what can really be counted on to prevent motion, as long as the details of cap geometry and material are up to the task.

6 or 8 flywheel-to-crank bolts. well tightened, very successfully keep that joint stable.

Any of the GM "race prepared" bow-tie blocks use steel caps with 4 splayed bolts AND large dowels. The dowels are for location.