Pics/info for installing a Main Stud Girdle on a LT1
05-09-2009, 01:45 PM
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Pics/info for installing a Main Stud Girdle on a LT1 Ok, here is a link to a bunch of pics of a SBC Main Stud Girdle installed on a LT1:
http://www.darklogic.net/WindageTrayInstalled/
To install one on a LT1 here is a listing of issues:
- Rear main bolt holes do not line-up - You must elongate the bolt holes to allow for the LT1s bolt locations. Care MUST be taken that too much material is not removed. I used, and would suggest the same to anyone else doing this, a large diameter hardened washer that will allow distribution of the load at this point to as much of the girdles material as possible. You can compare the size of the washer I used to the 'normal' washer that is used on all the rest of the nuts in the first few pics.
- The other rear main stud location interferes with the oil pump, thus the oil pump must be clearenced for the stud/nut. You must also use a reduced head nut at this location. The stud kit includes a reduced head nut for this location. You can see how much the oil pump needed to be clearenced in the pictures provided. I used a cartridge roll to do the clearencing as it work quite well on the oil pumps material.
- Clearence the girdle for the oil pump driveshaft.
- Clearence the girdle for the crank counterweights. You can see in a few of the pics where I had to chamfer the corners for the counterweights.
- Drill a hole for the oil dipstick. I drilled it in such a way that a shortened dipstick tube locates itself inside the hole and it directs the dipstick to just clear past the main stud that is inline to it.
- Clearence the stock oil pan in back for the main girdle near the oil filter mount, as well as in front on both sides where it curves inward. This was one of the biggest PITA aspects, only because I am meticulous and the end result didn't turn out as 'pretty' as I would have wanted, but is 100% functional as well as 'hidden' sitting under the car. And, honestly, with a fresh coat of paint it isn't bad at all.
I also utilizied 7 of the long 5140 studs included with the main girdle kit, and used 3 Moroso main studs for use with the windage tray. Those 3 Moroso studs were installed 2 threads shorter into the block to allow for the complete nut engagement to the threads that stick above the main girdle and to allow for the proper height for mounting the windage tray. Since these studs are longer than ARP main studs by about the same amount it was prudent to install them that way.
The torque spec for the 5140 stud supplied is 60 ft/lbs with ARP moly lube. The Moroso studs are spec'd at 65 ft/lbs with oil and per a conversation with Moroso 60 ft/lbs with ARP moly lube is applicable as well, so I used 60 ft/lbs for all 10 studs.
I did prefer to use all ARP nuts and washers for this application, more out of personal preference than anything else. The nuts/washers supplied with the stud girdle kit should do just fine as well.
For piece of mind I not only used ARP moly lube during fitting, but I also choose to torque, loosen and retorque the main studs a total of 5 times each upon final assembly to ensure consistent clamping loads.
I did use a rear pan baffle to keep excessive amount of oil from running into the rear of the crank on acceleration. I used a soft-copper oil pump gasket at the location on top of the rear main, more out of 'insurance' than a necessity as I made sure the mount was flat on both that and the oil pump itself. I also chamfered the oil feed hole on the rear main cap as well.
The oil pump used is a Melling 10552 +10% volume, hi-pressure pump. It is used with a 12558 pickup for a 7-1/2" depth stock pan.
The stock windage tray clears the stock rods/Scat 9000 crank combo with more than .100" of clearence.
On this buildup I was happy to find the following bearing clearences upon assembly:
Rear Main: .0035"
1-4 Mains: .0025"
Rods: .002"
Thrust: .004"
I used ACL Race H-Series bearings.
I was really happy to find these consistencies because the crank was only polished and balanced (as it was used in a different motor build before) and the block was not line honed. The rods did have ARP bolts installed and where reconditioned, clearenced for the 383 and balanced with Speed Pro forged flat-top pistons (looking at 11.6:1 CR) along with Hastings Race Series Plasma-Moly standard-fit rings. The block was washed, decked, bored, honed and clearenced for the 383 with new cam bearings and all new freeze plugs and whatnot installed (I will note that the oil galley plugs do not have .030" holes in them to supply extra oil for a standard LT1 timing set, but that is of no matter seeing how I am going with an electric waterpump and heavy-duty SBC roller timing set). The timing set is a Pro-Gear single roller that clears the timing cover without needing clearencing. The rear main I opted for was the Teflon version as I feel it has better long-term sealing, even though, with a T56, it is a simple thing to replace the rear main when you need to do the clutch. I will note that the Teflon seal will wear the crank more than a 'standard' rubber rear main will and that you also cannot use a Teflon rear seal with a rear main repair 'sleeve'.
I did paint the block with POR 15 engine paint. Didn't even mask the block and it was WAY easier and faster painting it with foam brushes vs spray painting. I also feel it is a thicker coating of paint as well.
One thing of note was a chunk of sand-cast material being stuck between cylinders 1 & 3 in the water-jacket of this block. It would explain the broken piston rings and ring lands on those pistons upon disassembly of the stock shortblock. Took me almost an hour to breakup and shake-out all the pieces before I built iy up this time. I can only imagine how badly it caused those two cylinders to overheat when the motor was stock.
I am expecting around 540HP/520TQ out of this setup when all is said and done. The rest of it is custom cam, CNC'd heads, FLP long-tube headers, 1.6 stainless rockers, 7/16" rocker arm studs w/guideplates, Trickflow pushrods, Comp R lifters, electric waterpump and 58mm BBK throttlebody. The intake manifold was ported as well. The heads have a set of Lunati BBC beehive springs/seats/retainers with .050" locks to give proper installed height, along with Manley Race-Flo valves. All gaskets are Fel-Pro except for the headers which are Mr. Gasket, only because they fit the ports better for this application. The clutch being used with this app is a Zoom HP dual Kevlar. It is a little grabby until you learn how to slip it properly, but holds great for these kinds of power levels.
http://www.darklogic.net/WindageTrayInstalled/
To install one on a LT1 here is a listing of issues:
- Rear main bolt holes do not line-up - You must elongate the bolt holes to allow for the LT1s bolt locations. Care MUST be taken that too much material is not removed. I used, and would suggest the same to anyone else doing this, a large diameter hardened washer that will allow distribution of the load at this point to as much of the girdles material as possible. You can compare the size of the washer I used to the 'normal' washer that is used on all the rest of the nuts in the first few pics.
- The other rear main stud location interferes with the oil pump, thus the oil pump must be clearenced for the stud/nut. You must also use a reduced head nut at this location. The stud kit includes a reduced head nut for this location. You can see how much the oil pump needed to be clearenced in the pictures provided. I used a cartridge roll to do the clearencing as it work quite well on the oil pumps material.
- Clearence the girdle for the oil pump driveshaft.
- Clearence the girdle for the crank counterweights. You can see in a few of the pics where I had to chamfer the corners for the counterweights.
- Drill a hole for the oil dipstick. I drilled it in such a way that a shortened dipstick tube locates itself inside the hole and it directs the dipstick to just clear past the main stud that is inline to it.
- Clearence the stock oil pan in back for the main girdle near the oil filter mount, as well as in front on both sides where it curves inward. This was one of the biggest PITA aspects, only because I am meticulous and the end result didn't turn out as 'pretty' as I would have wanted, but is 100% functional as well as 'hidden' sitting under the car. And, honestly, with a fresh coat of paint it isn't bad at all.
I also utilizied 7 of the long 5140 studs included with the main girdle kit, and used 3 Moroso main studs for use with the windage tray. Those 3 Moroso studs were installed 2 threads shorter into the block to allow for the complete nut engagement to the threads that stick above the main girdle and to allow for the proper height for mounting the windage tray. Since these studs are longer than ARP main studs by about the same amount it was prudent to install them that way.
The torque spec for the 5140 stud supplied is 60 ft/lbs with ARP moly lube. The Moroso studs are spec'd at 65 ft/lbs with oil and per a conversation with Moroso 60 ft/lbs with ARP moly lube is applicable as well, so I used 60 ft/lbs for all 10 studs.
I did prefer to use all ARP nuts and washers for this application, more out of personal preference than anything else. The nuts/washers supplied with the stud girdle kit should do just fine as well.
For piece of mind I not only used ARP moly lube during fitting, but I also choose to torque, loosen and retorque the main studs a total of 5 times each upon final assembly to ensure consistent clamping loads.
I did use a rear pan baffle to keep excessive amount of oil from running into the rear of the crank on acceleration. I used a soft-copper oil pump gasket at the location on top of the rear main, more out of 'insurance' than a necessity as I made sure the mount was flat on both that and the oil pump itself. I also chamfered the oil feed hole on the rear main cap as well.
The oil pump used is a Melling 10552 +10% volume, hi-pressure pump. It is used with a 12558 pickup for a 7-1/2" depth stock pan.
The stock windage tray clears the stock rods/Scat 9000 crank combo with more than .100" of clearence.
On this buildup I was happy to find the following bearing clearences upon assembly:
Rear Main: .0035"
1-4 Mains: .0025"
Rods: .002"
Thrust: .004"
I used ACL Race H-Series bearings.
I was really happy to find these consistencies because the crank was only polished and balanced (as it was used in a different motor build before) and the block was not line honed. The rods did have ARP bolts installed and where reconditioned, clearenced for the 383 and balanced with Speed Pro forged flat-top pistons (looking at 11.6:1 CR) along with Hastings Race Series Plasma-Moly standard-fit rings. The block was washed, decked, bored, honed and clearenced for the 383 with new cam bearings and all new freeze plugs and whatnot installed (I will note that the oil galley plugs do not have .030" holes in them to supply extra oil for a standard LT1 timing set, but that is of no matter seeing how I am going with an electric waterpump and heavy-duty SBC roller timing set). The timing set is a Pro-Gear single roller that clears the timing cover without needing clearencing. The rear main I opted for was the Teflon version as I feel it has better long-term sealing, even though, with a T56, it is a simple thing to replace the rear main when you need to do the clutch. I will note that the Teflon seal will wear the crank more than a 'standard' rubber rear main will and that you also cannot use a Teflon rear seal with a rear main repair 'sleeve'.
I did paint the block with POR 15 engine paint. Didn't even mask the block and it was WAY easier and faster painting it with foam brushes vs spray painting. I also feel it is a thicker coating of paint as well.
One thing of note was a chunk of sand-cast material being stuck between cylinders 1 & 3 in the water-jacket of this block. It would explain the broken piston rings and ring lands on those pistons upon disassembly of the stock shortblock. Took me almost an hour to breakup and shake-out all the pieces before I built iy up this time. I can only imagine how badly it caused those two cylinders to overheat when the motor was stock.
I am expecting around 540HP/520TQ out of this setup when all is said and done. The rest of it is custom cam, CNC'd heads, FLP long-tube headers, 1.6 stainless rockers, 7/16" rocker arm studs w/guideplates, Trickflow pushrods, Comp R lifters, electric waterpump and 58mm BBK throttlebody. The intake manifold was ported as well. The heads have a set of Lunati BBC beehive springs/seats/retainers with .050" locks to give proper installed height, along with Manley Race-Flo valves. All gaskets are Fel-Pro except for the headers which are Mr. Gasket, only because they fit the ports better for this application. The clutch being used with this app is a Zoom HP dual Kevlar. It is a little grabby until you learn how to slip it properly, but holds great for these kinds of power levels.
05-10-2009, 09:06 AM
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Also, since someone asked, sorry, but I did not take any pics of the modified girdle by itself uninstalled.
It really isn't that hard to do, just time consuming and you have to pay close attention to what you are doing.
It really isn't that hard to do, just time consuming and you have to pay close attention to what you are doing.
05-10-2009, 12:12 PM
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Yes, they are sold by Jegs, but instead of $75 they are like $250. That and the fact that the ones on Jegs are like 1/3-1/4 the thickness of the other ones, I question the 'effectiveness' of such a thin girdle, as well as if it will clear the throws near where the oil-filter mounts. Those concerns coupled with the added price pretty much made it a no-sale for me.
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05-10-2009, 02:33 PM
#11
To be honest if you plan on keeping it it may be worth converting it to splayed mains before you have it in the car. A lot of added insurance for relatively not a lot of cash.
05-10-2009, 03:01 PM
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Please, stop spreading misinformation. Splayed 4-bolt mains on a LT1 are WEAKER than straight 4-bolt mains, due to the fact that LT1s have less material in the webbing. LT1s also have deeper cooling passages in the block due to the reverse cooling aspect as well.
The strongest block you can have is a straight 4-bolt main conversion done on a seasoned 2-bolt block, then add a stud girdle. No issues taking that combo to above 1100hp.
The strongest block you can have is a straight 4-bolt main conversion done on a seasoned 2-bolt block, then add a stud girdle. No issues taking that combo to above 1100hp.
05-10-2009, 04:34 PM
#16
Please, stop spreading misinformation. Splayed 4-bolt mains on a LT1 are WEAKER than straight 4-bolt mains, due to the fact that LT1s have less material in the webbing. LT1s also have deeper cooling passages in the block due to the reverse cooling aspect as well.
The strongest block you can have is a straight 4-bolt main conversion done on a seasoned 2-bolt block, then add a stud girdle. No issues taking that combo to above 1100hp.
The strongest block you can have is a straight 4-bolt main conversion done on a seasoned 2-bolt block, then add a stud girdle. No issues taking that combo to above 1100hp.
This is common knowledge, and has been that way for years.
05-10-2009, 04:42 PM
#18
LT1 engines have MORE material in the webbing which makes then stronger then traditional SBC's with straight mains, and splayed mains are even stronger still.
There are many more 700hp LT1s on the internet then there are on the street.
There are many more 700hp LT1s on the internet then there are on the street.
05-10-2009, 04:48 PM
#19
Yup, So I have an 8.1 liter it must make a 1000 horse power then.. Hellz yes!!!
05-10-2009, 04:57 PM
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Arguing with idiots on here is a losing battle, as the morons have far more experience in being dumb than those with any real knowledge or experience in actually accomplishing anything.