[taff2]

Yes, KRE would be the company I could see doing these, they have the foundry links and CNC equipment, are they a viable product though?

[ponjohn]

Originally Posted by charlie66

Its not the amount of boost , its the amout of power the engine is producing that walks the caps.....

Not RPM?

[Dragncar]

I asked Jeff at KRE if the experienced cap walk with their MR1 blocks. He said they did get a small amount of fretting on their 2000+ HP blown engines. Not catastrophic but at least a little.
I think a main girdle is a great idea if it could actually get made. Make it so it formed the top few inches of a "oil pan" and you could have a flattish oil pan like the Mopars have with some of their blocks. All those 5/16" bolt holes on the pan rail could be put to use for this. And have the LS style straight across main caps with the side bolts going through the sides of the girdle to the sides of the main caps tying it all together.
Waving in the wind thing is over and the oil pan rail of the block is adding strength helping with the caps not being shoved downward.
I bet it would add a lot of strength/reliability to PMD blocks. Could cast it out of malleable/ductile iron like the Milodon main caps are. Expansion rates would be the same as the iron block also so that is another good thing.

[charlie66]

Originally Posted by ponjohn

Not RPM?

True, I only said boost because someone was suggesting boost would do it..

[ponjohn]

Originally Posted by Dragncar

I asked Jeff at KRE if the experienced cap walk with their MR1 blocks. He said they did get a small amount of fretting on their 2000+ HP blown engines. Not catastrophic but at least a little.
I think a main girdle is a great idea if it could actually get made. Make it so it formed the top few inches of a "oil pan" and you could have a flattish oil pan like the Mopars have with some of their blocks. All those 5/16" bolt holes on the pan rail could be put to use for this. And have the LS style straight across main caps with the side bolts going through the sides of the girdle to the sides of the main caps tying it all together.
Waving in the wind thing is over and the oil pan rail of the block is adding strength helping with the caps not being shoved downward.
I bet it would add a lot of strength/reliability to PMD blocks. Could cast it out of malleable/ductile iron like the Milodon main caps are. Expansion rates would be the same as the iron block also so that is another good thing.

On FB Jeff was asking for suggestions for future products.

[taff2]

Dragncar, that's basically what I did when I built my girdle, though I drilled out and re-tapped the pan rail bolt holes to 3/8" UNF and used Allen head bolts. The new girdle I'm making will have a flat oil pan like you mentioned, sitting on the 1 -1/2" thick steel side skirts, and with a 3/4" -1" thick halo top plate instead of individual cap straps.
If KRE would make it,it would save me a lot of work!

[LPI]

It is great that you guys are taking the time to look into making parts for your own builds as well as possibly bringing more products to the Pontiac market place for a stock block build.

What you might want to ask if anyone has actually done it and then you might ask what happened and then you might ask the question as to why they may not be making or selling them.

Again making something for yourself to prove your own ideas or concepts are great, learning is always good.

We have seen first hand on a boosted engine cap walk or actual fretting between the two bolt cap and the oil pan rail/main cap face of the block.

It came out of pure stupidity and was created by our own mistake. yes we make mistakes, usually only in house but we do make mistakes and we learn from it to help our customers. It is called R&D.

It did teach us something and we have corrected the problem and it is way simpler and way more cost effective compared to a top mounted girdle.

For reference only, we have a girdle drawn up and modeled in Solidworks to fit all five caps and work with a stock pan. It is just not cost effective to make. KISS is a better approach.

Here is the simple answer, pictures supplied. You can buy the parts almost anywhere, McMaster sells all of it.

Any machine shop or any person with a Bridgeport type mill can do the work.

Could easily be adapted to a four bolt main cap on a stock block as well.

Carry on and best of luck in your endeavors. Again you guys are the pioneers.

[Jack Gifford]

The basis of your "stupidity" is not self-evident to this reader.

[taff2]

LPI, so basically you're using top hat washers to locate the top of the caps on the studs, and taller dowels? What HP have you used this procedure to? Thanks for the info.
When I fabbed my girdle the intention was not so much to stop cap fretting,but to help stop the block from cracking up through the mains.

[Half-Inch Stud]

Originally Posted by taff2

LPI, so basically you're using top hat washers to locate the top of the caps on the studs, and taller dowels? What HP have you used this procedure to? Thanks for the info.
When I fabbed my girdle the intention was not so much to stop cap fretting,but to help stop the block from cracking up through the mains.

Circa 1989, my 455 Block got cut PMD valve stems (11/32 =0.343") for main Dowels for the Steel Caps rather than 5/16 = 0.3125". They stuck-out of block about twice the Stock height.
I liked thaat.

Circa 1999 PY postings, i ranted to how the Main Studs are improperly designed= Girthy look being nice but they dont locate well on the Cap-Seat like Stock Bolts, and the studs dont stretch in the length section like Cap Bolts. I suppose Such Generic Main Studs have their benefit in IA & KRE Blocks for high RPM activities. I suppose locating Washers "fix" the Stud deal if they dont crackout. Pressing a bronze sleeve into the Main Cap hole (to match the Stud dia) sounds trick to me.
Otherwise, I remain rather fond of stock Main Cap Fasteners for Stock Blocks (with any Main Caps) applied to ~< 5600 RPM use.

[RUDOLFSSON]

Agreed... Every rebuild should include re-doweling to the next size for fresh set of bores and to gain tighter tolerance specs...

Metric 8.0 mm dowels is a size close by and worked well for me.


Kris.

[taff2]

I used longer 8mm dowels in the mains caps when I built my girdle, they came up to the top of the dowel holes in the caps, not far off an inch long,as seen in this pic. I'm not changing the dowels this time though, I don't really see the need for them being taller when fitting a girdle that is going to be dowelled to the pan rails and main caps anyway.

[hurryinhoosier62]

Originally Posted by Half-Inch Stud

Circa 1989, my 455 Block got cut PMD valve stems (11/32 =0.343") for main Dowels for the Steel Caps rather than 5/16 = 0.3125". They stuck-out of block about twice the Stock height.
I liked thaat.

Circa 1999 PY postings, i ranted to how the Main Studs are improperly designed= Girthy look being nice but they dont locate well on the Cap-Seat like Stock Bolts, and the studs dont stretch in the length section like Cap Bolts. I suppose Such Generic Main Studs have their benefit in IA & KRE Blocks for high RPM activities. I suppose locating Washers "fix" the Stud deal if they dont crackout. Pressing a bronze sleeve into the Main Cap hole (to match the Stud dia) sounds trick to me.
Otherwise, I remain rather fond of stock Main Cap Fasteners for Stock Blocks (with any Main Caps) applied to ~< 5600 RPM use.

Actually, Mark, your idea of bushing main caps makes good sense. I have seen few stock main caps that didn’t need to be “tweeted” to utilize ARP main studs correctly. In my case, I ream the main cap bolt bosses to slightly enlarge the hole. A coat of Prussian blue shows where any interference occurs. The idea of bushing main caps to properly locate them and ensure proper torquing is one that I would definitely pursue.

[pontbil]

Any progress on these

[LStathas]

Originally Posted by hurryinhoosier62

Actually, Mark, your idea of bushing main caps makes good sense. I have seen few stock main caps that didn’t need to be “tweeted” to utilize ARP main studs correctly. In my case, I ream the main cap bolt bosses to slightly enlarge the hole. A coat of Prussian blue shows where any interference occurs. The idea of bushing main caps to properly locate them and ensure proper torquing is one that I would definitely pursue.

The idea of bushing a main cap is fine but it would require precision ground O.D. studs that are concentric with the threads. Like a shoulder bolt. Otherwise you run the risk of actually "preloading" cap walk. Bottom line is there is no free lunch. There are many ways to address the issue. None of them are easy or cheap unless you are an experienced machinist and have access to the tools to do it. That's my 2 cents..

[smokey 1978]

J&S Oldsmobile makes his for the olds motors maybe he can help he is on facebook

[smokey 1978]

Here is more info about girdle.

[Dragncar]

When I called Jeff K for some parts I asked him what he thought about a Pontiac main girdle like we are talking about. He said it made sense if we had no aftermarket block because of machining costs. There are local Buick guys in his area who do the main girdle thing. And he told me a shop that does them for the Buick guys spend a entire day setting up equipment to do the job. Thats before any work gets done, expensive.
So, unless you can do a bunch of the stuff yourself it does not make sense from a cost perspective.

[taff2]

That's what I think, ^^, for a girdle to be a commercial success it has to fit over the existing 2 bolt main caps/studs and bolt to the pan rail area - without any machine work necessary. If you need to get a line hone/caps milling/ custom oil pan etc then it won't make economic sense as you'll be 1/2 way to the cost of an aftermarket block.
If I lived in the States with access to good machinists who know Pontiacs- I would use splayed 4 bolt caps with a steel halo girdle on top of them, use an early good block and nothing more than a 4.00" stroke. jmo

[73 TRANSAM]

Finally started to make one for my IA2 block. It took literally 3 days to make this as I want it to be very stiff and fully functional. It won’t work with the stock oil pan but u can certainly modify it. Here are some finished pictures.