[Chipped Tooth]

Thinking about making a main girdle for a 400 block.

Working with 4 bolt main caps in center.

I have seen them work wonders in the Phord community.

[Aaron Quinton]

Man, I'm not sure they're worth the effort but if you have experience with them working fair enough. In my mind a main girdle will help if the bending in the block bulkhead driven by axial load is significant (through the centerline of the crank). On high HP high cylinder pressure cars this could make sense due to crank and block bending. I'm not sure on NA engines. What applications have you seen in work on Fords? They are all air pumps man. :-)

[screamingchief]

This has come up in the past a few times already,majority opinion back then leaned mostly towards those who did'nt care for the idea,due mostly to the "crutch fix" nature of a main girdle.

So be prepared as this thread might just warm up some.

Also be ready for some to "over-think" the whole plan too,and turn it into a monumental piece of complexity.

Originally Posted by Aaron Quinton

What applications have you seen in work on Fords?

Thye're used a lot in stock block stroker SBF.

Especially the stock block 351w based strokers.

Common on 403 Olds too,among others.

Common anytime there are limited aftermarket or OE hi-po block options really.

I say if you want one,and are willing to go thru the trouble,by all means go for it.

FWIW

Bret P.

[Aaron Quinton]

So for those who "over-think" the whole plan, what problem do the girdles solve?

For those who "under-think" the situation, continue to spend money on problems that don't exist.

Originally Posted by screamingchief

This has come up in the past a few times already,majority opinion back then leaned mostly towards those who did'nt care for the idea,due mostly to the "crutch fix" nature of a main girdle.

So be prepared as this thread might just warm up some.

Also be ready for some to "over-think" the whole plan too,and turn it into a monumental piece of complexity.


Thye're used a lot in stock block stroker SBF.

Especially the stock block 351w based strokers.

Common on 403 Olds too,among others.

Common anytime there are limited aftermarket or OE hi-po block options really.

I say if you want one,and are willing to go thru the trouble,by all means go for it.

FWIW

Bret P.

[Chipped Tooth]

I was thinking of making it out of stainless.

I have seen many a Phord run them till the mains break.
Girdle was the only thing holding the web in.

Screamingchief, yes I know how things can get on the net lol.

Just wondering if anyone has used them before and there results :-)

[screamingchief]

Originally Posted by Aaron Quinton

So for those who "over-think" the whole plan, what problem do the girdles solve?

For those who "under-think" the situation, continue to spend money on problems that don't exist.

The problem that one tries to solve with a main girdle is largely due to the main caps "walking",plain & simple.

And that problem does indeed exist with stock pontiac blocks,especially @ higher HP levels.

Whether one feels a main girdle will actually help that problem,that's where the debate will come into play.

The "over-thinking" deal comes from some guys feeling that the main girdle wont do squat unless you machine some massive chunk of billet that'll tie the main girdle to the pan rails and front & rear mains,basically turning the stock pontiac block into a fully skirted block like a top fuel hemi or the FE side-bolt blocks.

Underthinking,I dunno anything about that,dont quite understand what you're getting @ with that comment?

As stated above,the problem does exist,so arguing about that would be silly.

Bret P.

[steve25]

I like making stuff too, but with your time and effort in making such a thing would not a aftermarket block make more sence.
certianly at any power level you need a gridle at your not locked into having to use a factory block like in class racing, no?

[Half-Inch Stud]

Suppose a fine 5-Main girdle IS made to handle all the load duty, then surely the block Main-Bolt bulkheads are helped.

A fella has to design the girdle to take the loads handled by the INNER BOLTS. Can the girdle perimeter be helped?

[johnta1]

Steve Barcak made his own.

Try looking at www.pontiacheaven.org

[BruceWilkie]

Mondellos (Joe Mondellos race engines in Crossville TN 931-459-2760) has a one piece billet cage for Olds AND Pontiac.
(Both Mondello cages are far better than anybody elses cage for other motors including Olds pieces already out there)

The Pontiac version is intended for extreme power apps and aftermarket blocks.... I've seen it, its a nice piece(going on a MR1 2000 HP plus application)... it can be fit to a stock block... but cost is a factor... An IA2 or MR1 is more cost effective for anything your going to throw at it NA and even most PA applications.

More info on the main cage assembly... http://www.cv-1channel.com/forums/sh...ntiac-MR1-CAGE

Stock block... no question it will tighten things up... if you already have a hard to find 60 or older block, RAV block or SD455 block it might be something to consider if you are going extreme... it still wont be as strong as with an aftermarket block though. (cage capacity stronger than rest of block)

BTW Steel or nodular iron would be a heck of a weight penalty IMO.
Factory 4 bolt block has outer two holes in a weak area of the webs...a 2 bolt block with 4 bolt splayed helps keep the block pulled together.
A conventional girdle or halo or both might help some but not much. Cost of making then fitting properly you are back to cost of buyin an IA2 or MR1...

[Chipped Tooth]

Wow that's a fancy girdle !!!!!!

As far as aftermarket block for this guy is way outta reach.

I have acsess to laser and water tables so cost will be just material I use.

I look at it this way, if a girdle can make a weenie Phord hold together for about a summer with a 300 shot where as before about 3 to 4 weekends before a main web would break it shure can't hurt if cost is minimal and I will only have my own time in it.

The design I'm looking to make will be similar to the Phord design.

[RAIV55]

I've often seen fretting between the block and caps on many different makes of engines. Like Bret mentioned it almost epidemic in the 351 Fords and to a lesser extent with others. I noticed after installing girdles on customer engines, when coming back for refreshing, the metal transfer was gone or almost nonexistant.
Was discussing this with a cam grinder and he told me he wasn't surprised. He said on the spinatron the caps wave like tall grass in the wind.
Now with engines that have thin, weak webs and are prone to breakage, I don't see where girdles has a hurt a thing and in many cases has extended service life.
"Under thinking" or "over thinking" I'm not sure but I know a problem exists.
Just a passing thought here, Ever wonder why high performance Pontiacs have windage tray problems using the stock pieces?

[screamingchief]

I agree,cant see that it hurts anything,and almost certainly helps reduce cap walk some.

I've never seen it as a replacement for an aftermarket block,just a way to help a stock block stay together as long as it can,which might help buy some racers enough time to save up for the aftermarket blocks vs. having the race car down that whole time.

Chipped Tooth,I'm curious if you might be thinking about making a few extra and selling 'em to help defer the upfront time and cost to make them for yourself?

If so I'll bet a few others here will be interested,I know I might be.

Bret P.

[Skip Fix]

I've seen them on a few high HP Buick motors also.

[Chipped Tooth]

I would have no problem making extra, once the program is in ya just have to load the material.

I'll be tinkering with it soon once work slows down, I will shure post pics on how its going once I start on it.

[Aaron Quinton]

I'm with you now. Main cap walking is a bolted joint problem where the loads on the main cap are higher than the bolts can carry. Increasing the clamp load will solve this issue with better bolts, better studs or more of either (4 bolt caps). A main stud girdle would have to be massive to be effective in solving this problem because the loads are perpendicular to crank axis which puts the girdle in bending. A girdle would help if blocks were failing at the last engaged main thread in the main boss by increasing axial strength by locking the mains together (by increasing crank axis bending strength in the block). Make sense?

I agree the problem exists. I'm just thinking through whether the parts sold or made will solve the problem or not. It certainly won't hurt anything.

A lot of times companies will sell large packages of parts to increase performance when a single part is the majority of the improvement. The diesel industry in great at this. People sell performance intakes, exhaust manifolds, etc. along with calibrations to increase power. They sell you $5000 worth of parts when $500 of the "kit" does 95% of the improvement. It's all about increasing fueling in a diesel.

Originally Posted by screamingchief

The problem that one tries to solve with a main girdle is largely due to the main caps "walking",plain & simple.

And that problem does indeed exist with stock pontiac blocks,especially @ higher HP levels.

Whether one feels a main girdle will actually help that problem,that's where the debate will come into play.

The "over-thinking" deal comes from some guys feeling that the main girdle wont do squat unless you machine some massive chunk of billet that'll tie the main girdle to the pan rails and front & rear mains,basically turning the stock pontiac block into a fully skirted block like a top fuel hemi or the FE side-bolt blocks.

Underthinking,I dunno anything about that,dont quite understand what you're getting @ with that comment?

As stated above,the problem does exist,so arguing about that would be silly.

Bret P.

[BruceWilkie]

http://www.wallaceracing.com/hemi-1.html.... Pontiac thought it was a good idea... take a close look at some of the photos...

Keep in mind the Mondello cage allows a simple oil pan as the side rails add depth... basically take an existing pan...section out the rail height.... add a simple flat flange.

It isnt "just" a girdle or "halo".... its a complete bottom end.

Keep in mind this one is aluminum... and strong design reasonable weight... splayed outer bolts plus it bolts to rail... I doubt it moves anywhere....if nodular iron or steel it would weigh alot... like an iron storm drain along the street... Ever lift one of those?

Prior to findin out Cody was workin on this cage I rough mocked one in wood... looked into having a nodular iron casting... all things considered pricing wouldnt be bad... but when I started picking up suitably sized steel/iron scraps to make a better model I stopped... the weight would be rediculous... making it smaller/lighter same material... would not be as strong as what Cody built.... I think a cast copy of Mondellos cage in high strength aluminum(355-T7?) could be a more cost effective addition for a stock block...

No matter which way you go... it still requires the machine shop to fit it to the block... line bore/hone etc..

Rough guesstimate to put the Mondello billet cage on my 59 block... fasteners and fitting plus make my own pan... $1100-$1500... dont quote me on that talk to Tim at Mondellos.

[Aaron Quinton]

If Pontiac or anyone else can't explain what problem the girdle solves and how, I'm not interested.

Originally Posted by BruceWilkie

http://www.wallaceracing.com/hemi-1.html.... Pontiac thought it was a good idea... take a close look at some of the photos...

Keep in mind the Mondello cage allows a simple oil pan as the side rails add depth... basically take an existing pan...section out the rail height.... add a simple flat flange.

It isnt "just" a girdle or "halo".... its a complete bottom end.

Keep in mind this one is aluminum... and strong design reasonable weight... splayed outer bolts plus it bolts to rail... I doubt it moves anywhere....if nodular iron or steel it would weigh alot... like an iron storm drain along the street... Ever lift one of those?

Prior to findin out Cody was workin on this cage I rough mocked one in wood... looked into having a nodular iron casting... all things considered pricing wouldnt be bad... but when I started picking up suitably sized steel/iron scraps to make a better model I stopped... the weight would be rediculous... making it smaller/lighter same material... would not be as strong as what Cody built.... I think a cast copy of Mondellos cage in high strength aluminum(355-T7?) could be a more cost effective addition for a stock block...

No matter which way you go... it still requires the machine shop to fit it to the block... line bore/hone etc..

Rough guesstimate to put the Mondello billet cage on my 59 block... fasteners and fitting plus make my own pan... $1100-$1500... dont quote me on that talk to Tim at Mondellos.

[65nss4spdGTO]

Anyone consider the downside to adding a cage to a Pontiac engine?

Calvin Hill
Hill Performance
708-250-7420

[Half-Inch Stud]

Originally Posted by 65nss4spdGTO

Anyone consider the downside to adding a cage to a Pontiac engine?

Calvin Hill
Hill Performance
708-250-7420

Well; A flexing crank will NEED the Lower bearings to follow the crank journal flex, a least a little. Main Caps allow such wafting to avoid journal-bearing shell axial misalignment. I think.