[BruceWilkie]

Originally Posted by 65nss4spdGTO

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

Calvin Hill
Hill Performance
708-250-7420

Besides having to pull the whole thing to inspect mains and sectioning an oil pan and using a flat flange like a Mopar B/RB/Hemi block...
Fitting it wasnt much more difficult than converting to splayed caps... Cody's piece clears a Titan pump(stock pump fits too). He also made provision for removal with out jack screws...

Dis-similar expansion characteristics of the cage vs block??? You put steel caps on aluminum blocks...

So... lets hear your thoughts on it... I'm curious.

[65nss4spdGTO]

Originally Posted by BruceWilkie

Besides having to pull the whole thing to inspect mains and sectioning an oil pan and using a flat flange like a Mopar B/RB/Hemi block...
Fitting it wasnt much more difficult than converting to splayed caps... Cody's piece clears a Titan pump(stock pump fits too). He also made provision for removal with out jack screws...

Dis-similar expansion characteristics of the cage vs block??? You put steel caps on aluminum blocks...

So... lets hear your thoughts on it... I'm curious.

The added support and strength can be a benefit, but I feel any main issues on a Pontiac stems from the machining, the crankshaft and the engine tune. I can see blower applications that have more usable power like an AJ designed build put support and strength as the number goal.

The big downside is windage. High HP power NA engines don't use a skirted style block.

Calvin Hill
Hill Performance
708-250-7420

[Chipped Tooth]

I would think a stiffer block would minimize crank flex.

I also disagree on the skirted block design, all new factory engines are all skirted as well as the F1 stuff and there isnt much more out there that needs oil control than those high winding things.

I have seen first hand what a simple pice of steel can do for a factory Phord block.....

And that's enough for me to want to make one for mine, all we have around here is fox body junk getting hosed till they nuke or boosted till the head gaskets push out.

The Nitrous stuff breaks the most blocks !!!!!

[Tom Vaught]

"Engineers do stuff for reasons"

"Smart Racers do stuff for reasons too, vs copy the other guy's stuff"

That being said, I AGREE with this: "I also disagree on the skirted block design, all new factory engines are all skirted as well as the F1 stuff and there isnt much more out there that needs oil control than those high winding things.

I have known a lot of BB Chebby stock block guys who hurt their stuff 427 and 454 stuff. The LS (Skirted Blocks) are making far more power vs the "old day" BB Chebby blocks and living. But the typical 6 bolt main Skirted Block today is far more advanced vs the factory Ford/Chevy production block of previous times too.

John Mahovitz runs 6.05 in the quarter with a Ford 281 cid Ford GT style "skirted block" His block is not a Ford Block with a piece of steel attached to the mains.

Tom Vaught

[65nss4spdGTO]

Originally Posted by Tom Vaught

"Engineers do stuff for reasons"

"Smart Racers do stuff for reasons too, vs copy the other guy's stuff"

That being said, I AGREE with this: "I also disagree on the skirted block design, all new factory engines are all skirted as well as the F1 stuff and there isnt much more out there that needs oil control than those high winding things.

Tom Vaught

That being said, I DISAGREE with this statement and will stand behind why a skirted block will not make as much power as a non-skirted block.

Years ago, Reher Morrison did a simple dyno test. They tested an engine with a Pro-Stock oil pan, then tested the same engine by removing the pan and having oil pull from a source outside the open crank side of the engine. The engine WITHOUT the oil pan made more power.

F1 engines have such small strokes and crank surface area that windage is not the same as a long stroke V-8 engine.

Here is the latest Dart LS block and information from Dart:

http://www.dartheads.com/products/en...ext-block.html

Dart’s LS Next block is the first significant change in the architecture of the LS engine platform. By eliminating the “Y-block” design and utilizing conventional style main caps and oil pans, Dart has addressed the problems resulting from the LS engine’s separated crankcase bays. Windage is greatly reduced, resulting in increased power along with a much stronger main web area.

Take the time to watch the video by Dick Maskin.

If skirted blocks made the most power, NHRA Prostock blocks would have them.

Calvin Hill
Hill Performance
708-250-7420

[BruceWilkie]

Thanks Calvin... For Me...I'll trade longevity for a bit of windage loss...

Heres a thought... a cage like Cody made, one could still fit a scraper at/near the edge of where we typically mount one on a Pontiac... I guess one would have to test to see if it helps/hurts power. A fully skirted block you wouldnt be able to do that as easily.... I'm thinkin a scraper at crank horizontal center would control windage better than a scraper at the bottom of a deep skirt block.

[lemans411]

Originally Posted by 65nss4spdGTO

The added support and strength can be a benefit, but I feel any main issues on a Pontiac stems from the machining, the crankshaft and the engine tune. I can see blower applications that have more usable power like an AJ designed build put support and strength as the number goal.

The big downside is windage. High HP power NA engines don't use a skirted style block.

Calvin Hill
Hill Performance
708-250-7420

wouldnt a dry sumped engine help windage also?

[Stan Weiss]

Originally Posted by BruceWilkie

Thanks Calvin... For Me...I'll trade longevity for a bit of windage loss...

Heres a thought... a cage like Cody made, one could still fit a scraper at/near the edge of where we typically mount one on a Pontiac... I guess one would have to test to see if it helps/hurts power. A fully skirted block you wouldnt be able to do that as easily.... I'm thinkin a scraper at crank horizontal center would control windage better than a scraper at the bottom of a deep skirt block.

Bruce,
Are you talk bracket engine or all out max hp per ci? I can tell you in the mid 70's that the Billy Stepp Pro Stock hemi engines had the inside of the block between the mains was milled and a scraper / windage tray installed.

Stan

[65nss4spdGTO]

My point in bringing the windage issue was with any engine design change, you will have to make a sacrifice. I don't believe the gage or a skirted block design is needed for 98% of the Pontiac builds. To me, there are so many other upgrades to be made. The first weak link in the factory block is the lifer bores and even though steps can be made to improve it, the design was compromised. Four bolt main caps added to a factory block is an improvement, but not as important as a high quality crankshaft and proper machining on the main tunnel. The quality of the castings and components used is at the top of the list. The factory Pontiac cast iron blocks and heads are some of the best castings ever made. I recently ported on a set of Ford FE heads and the casting quality is far inferior to a set of same era Pontiac heads.

I'll add more more thought to this thread. Over the years, I've seen a bad execution of a design improvement that the end result would have been better if the original design was never modified. Don't fix it if it isn't broken.

Calvin Hill
Hill Performance
708-250-7420

[65nss4spdGTO]

Originally Posted by lemans411

wouldnt a dry sumped engine help windage also?

Yes it would, any improvement to getting the oil out of the way will help as long as it doesn't remove oil from any place needed.

BTW, I'm not knocking your build and in your case power will not be the issue, anything that can be done effectively to enhance the strength of your bottom end is a plus.

Calvin Hill
Hill Performance
708-250-7420

[lemans411]

Originally Posted by 65nss4spdGTO

Yes it would, any improvement to getting the oil out of the way will help as long as it doesn't remove oil from any place needed.

BTW, I'm not knocking your build and in your case power will not be the issue, anything that can be done effectively to enhance the strength of your bottom end is a plus.

Calvin Hill
Hill Performance
708-250-7420

i didnt take it that way anyway

[taff2]

I built a basic girdle for the bottom end of my '59 389 block (along with welding up the lifter valley area-but that's another story altogether),it is intended to mimic a skirted block and help the block live longer at the 1200-1400 hp I should make. It is however a LOT of work and a pain in the arse to do regular maintenance checks on the bearings,not to mention that the oilpan is a pain to fab,if I was to do it all again then,well, I wouldn't! I would use splayed 4 bolt centre caps and be happy with that. In fact, if I was building a naturally aspirated engine using an early block I would be quite confident in using the stock 2 bolt caps(which are quite a bit taller and beefier than later caps) with ARP studs and a lightweight rotating assembly,certainly up to the power levels that this sort of engine could produce-maybe 800hp?

[Half-Inch Stud]

taff2 that is brutally impressive work.

After doing all that, it seems you've been through the Valley of Death, and now see the light.

I too prefer the stock 2- Bolt undrilled.

As for the Lifter Valley: has anyone poured molten aluminum into lifter braces, in the valley? Seems a simple steel wool dam would hold it. HIS

[Chipped Tooth]

Taff2 that's quite the pice.

Half inch, Yes there is a guy that pours Aluminum for a lifters brace, His name is Greg

He used to build Pontiac engines, can't remember his website name or if he even still has one.

I bought most of his machine shop equipment but he didn't sell me the lifter brace mold.

[taff2]

By the way, the side skirts on my girdle were fitted with dowels into the cap braces after I took these pics and I have a full length scraper fitted on the cap studs to scrape oil off at the lowest point of the cranks swing, the oil then hits a mesh windage screen in the oil pan.
HIS,I like the idea of molten ali as a full lifter brace,sounds better than the glued in pieces I've seen with most kits,although I suppose you could pour a full support with some high tech epoxy. My reason for welding up the valley was to help stop block flex,now whether it was needed is another thing,and I can tell anyone contemplating doing it that it will distort the lifter bores enough so that you have to go to .875" Ford lifters,and the cam tunnel will need a clean up hone too. Another job that I wouldn't do again!

[Tom Vaught]

Originally Posted by taff2

I built a basic girdle for the bottom end of my '59 389 block (along with welding up the lifter valley area-but that's another story altogether),it is intended to mimic a skirted block and help the block live longer at the 1200-1400 hp I should make. It is however a LOT of work and a pain in the arse to do regular maintenance checks on the bearings,not to mention that the oilpan is a pain to fab,if I was to do it all again then,well, I wouldn't! I would use splayed 4 bolt centre caps and be happy with that. In fact, if I was building a naturally aspirated engine using an early block I would be quite confident in using the stock 2 bolt caps(which are quite a bit taller and beefier than later caps) with ARP studs and a lightweight rotating assembly,certainly up to the power levels that this sort of engine could produce-maybe 800hp?

What you did looks great.

Access to a CNC and a water jet machine could have possibly eliminated some of the time to make the thing but the concept/execution is very good.

Tom Vaught

[Half-Inch Stud]

Originally Posted by taff2

By the way...My reason for welding up the valley was to help stop block flex,now whether it was needed is another thing...Another job that I wouldn't do again!

yea my view is focus on the main journal & webs. The CYLs are independent of the VALLEY & Exterior, except Half-filled concrete will promote some transfer.

Point is: Main journal force-flex system is nearly independent of CYL side-load force system. Local forces may happen at the same time (60-70deg ABDC & 70-90ATDC & 30-0 BTDC)

So if you consider each CYL as an independent "loose jug", then the Mains can be treated as an isolated system with clear needs. That a full lower girdle COULD help, provided it did not rely on thin block main webs. Rather, the Block mains rely on the Girdle. Still begs for 2-bolt interface kept close to the Main Journal being sufficient.

Fact is each head keeps 4 jugs RIGID is terra-firma on the TDC side of the jug system.
That as each jug PULLS during POWER, and PULLS during Compression shows a minimal influence on the Block Mains system compared to localize Cap vs Girdle loading, because Each Cyl spreads it's force across a CYL base anchored into an iron mass covering Cam, 2 Main Cap webs, and oil rail.

So, a Girdle needs to be a COMPLETE Girdle to be effective; that the block can rely on, so that even a 301 block would say "no problem".

[Half-Inch Stud]

Tom Vaught ; Do you suppose a 1-piece cast iron girdle would be better than a (1-piece or fastened pieces) steel girdle?

[Tom Vaught]

Our Production Girdles are all one piece. Mostly used on Boosted Aluminum 4 cylinder stuff today. HIS

Tom Vaught

[Chipped Tooth]

I agree with what a full girdle can do.

But I'm only gonna make a simple one that bolts on over the caps utilizing the main studs.

My proof the simple design works is threw the Phord community, and if it can hold those together than it shure isn't gonna hurt on my Pontiac.