bolt torque for ram horns. - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Sport/Truck · 09-28-2008, 02:51 PM

I've tried searching everything and came up empty.
Anyone have the torque specs for ram horns manifolds?
s/t

Sport/Truck · 09-28-2008, 03:14 PM

I found it. one says 20 ft lb. and two others say 25 ft. lb. Both say with anti seize.
s/t

justcuz · 09-28-2008, 05:17 PM

Yea, I usually do 30 ft lbs or as tight as I can get them with one hand on a 9/16 long handle wrench. These are 3/8 bolts same as the intake and even though the intake only calls for 20 to 25 ft lbs I will usually go 27 to 30 because I hate intake leaks!

ChevLoRay · 09-28-2008, 06:06 PM

Make sure they're not warped.....it may be that they won't but then this note wouldn't matter.

I have three sets of ram's horn exhaust manifolds that I need to identify. Any websites that anyone knows of right off the top of your head?

68C15 · 09-28-2008, 10:02 PM

I would go for 20 ft.lbs. the manifolds grow as they heat up. if the bolts are too tight they will break and then the manifolds will be ruined from a major leak.

also, do NOT use any gasket. at the most a light film of ultra copper RTV sealant.

drivethechevy · 09-28-2008, 10:35 PM

Quote:

Originally Posted by 68C15

I would go for 20 ft.lbs. the manifolds grow as they heat up. if the bolts are too tight they will break and then the manifolds will be ruined from a major leak.

also, do NOT use any gasket. at the most a light film of ultra copper RTV sealant.

what is the purpose of not using the exhaust gaskets? seams to go again my better judgement, so please explain
nate

68C15 · 09-29-2008, 06:05 AM

unless you use the 2 layered stainless steel ones from GM they will blow out.

Sport/Truck · 09-29-2008, 06:24 AM

Quote:

Originally Posted by drivethechevy

what is the purpose of not using the exhaust gaskets? seams to go again my better judgement, so please explain
nate

No gaskets is the way they came from the factory. It has a wide flat surface to
seal with - along as it's not warped like ChevLoRay said.

s/t

Sport/Truck · 09-29-2008, 06:26 AM

Quote:

Originally Posted by 68C15

I would go for 20 ft.lbs. the manifolds grow as they heat up. if the bolts are too tight they will break and then the manifolds will be ruined from a major leak.

also, do NOT use any gasket. at the most a light film of ultra copper RTV sealant.

I used 25 foot lb torque. Do think that's too much? should I re do it?
s/t

Lugnut64052 · 10-01-2008, 02:21 AM

Quote:

Originally Posted by 68C15

also, do NOT use any gasket. at the most a light film of ultra copper RTV sealant.

Right on.
Take them to a machine shop and have them planed flat, then mount 'em up with no gaskets. You'll never have a leak.

Sport/Truck · 10-01-2008, 06:45 AM

Quote:

Originally Posted by Lugnut64052

Right on.
Take them to a machine shop and have them planed flat, then mount 'em up with no gaskets. You'll never have a leak.

I put the exhaust back on the same heads they came off, with out planing.
These are very flat with no indication of warpage.
s/t

**truckdude239** · 10-01-2008, 07:15 AM

umm i used gaskets with mine and have had no problems

**WorkinLonghorn** · 10-01-2008, 08:46 AM

Just for the record,the factory torque specs for the ram-horn exhaust manis is; 20 ft.lbs. for the outside bolts and 30 for the inside bolts.

Sport/Truck · 10-01-2008, 09:23 AM

Quote:

Originally Posted by WorkinLonghorn

Just for the record,the factory torque specs for the ram-horn exhaust manis is; 20 ft.lbs. for the outside bolts and 30 for the inside bolts.

Should I just leave them @ 25lb on all 6?
s/t

**WorkinLonghorn** · 10-01-2008, 11:05 AM

I guess so. I do think that those specs are important though,just due to the heat involved. I over torqued mine before I got the specs and later I noticed a crack,and had to replace the mani. 5lbs over/under may be safe.

justcuz · 10-01-2008, 11:07 AM

It won't hurt. If they don't leak don't sweat it. Just as an aside the intake manifold bolts torque to 35 ft. lbs. Even if the manifolds swell with heat the bolts will stretch a little too. I just drilled out the center holes in my sons 93 because they are almost impossible to get all the bolts in without extra movement. Funny the outers are 1/2 holes but the inners are 7/16, I drilled the inners to 1/2 also. I guess that is why a lot of 88 and up trucks crack exhaust manifolds.

Sport/Truck · 10-01-2008, 03:56 PM

Quote:

Originally Posted by justcuz

It won't hurt. If they don't leak don't sweat it. Just as an aside the intake manifold bolts torque to 35 ft. lbs. Even if the manifolds swell with heat the bolts will stretch a little too. I just drilled out the center holes in my sons 93 because they are almost impossible to get all the bolts in without extra movement. Funny the outers are 1/2 holes but the inners are 7/16, I drilled the inners to 1/2 also. I guess that is why a lot of 88 and up trucks crack exhaust manifolds.

The outer holes uses a thick washer, and the middle holes don’t. So did you use washers on the holes you drilled?
s/t

68C15 · 10-01-2008, 08:55 PM

the center holes are smaller because that is what locates the manifold. the outter holes are bigger to allow the manifold to grow lengthwise.

as far as the theory of the bolts and manifold both growing. they are made of different metals. the cast iron expands more under heat than steel.

72swbcamo · 10-01-2008, 09:04 PM

The outer ports of the exhaust manifold have locking plates on them. After you install and torque the bolts you bend over the tabs on the locking plates to secure the bolts. I don't see any one mentioning them.

09-28-2008, 02:51 PM	#1
Sport/Truck Sierra Grande Club Join Date: Jan 2007 Location: New Mexico USA Posts: 2,433	bolt torque for ram horns. I've tried searching everything and came up empty. Anyone have the torque specs for ram horns manifolds? s/t __________________ 1971 GMC Sierra Grande, 1/2 ton short wide, original 4 bolt 010 020 block & heads. (matching #'s). 383 stroker, SMI q jet 750 cfm, Lunati Voodoo 60102 cam, Scorpion roller rockers, Spin Tech pro street mufflers with X pipe.

09-28-2008, 03:14 PM	#2
Sport/Truck Sierra Grande Club Join Date: Jan 2007 Location: New Mexico USA Posts: 2,433	Re: bolt torque for ram horns. I found it. one says 20 ft lb. and two others say 25 ft. lb. Both say with anti seize. s/t __________________ 1971 GMC Sierra Grande, 1/2 ton short wide, original 4 bolt 010 020 block & heads. (matching #'s). 383 stroker, SMI q jet 750 cfm, Lunati Voodoo 60102 cam, Scorpion roller rockers, Spin Tech pro street mufflers with X pipe.

09-28-2008, 05:17 PM	#3
justcuz Registered User Join Date: May 2008 Location: Alta Loma, Ca. Posts: 930	Re: bolt torque for ram horns. Yea, I usually do 30 ft lbs or as tight as I can get them with one hand on a 9/16 long handle wrench. These are 3/8 bolts same as the intake and even though the intake only calls for 20 to 25 ft lbs I will usually go 27 to 30 because I hate intake leaks!

09-28-2008, 06:06 PM	#4
ChevLoRay Old Skool Club Join Date: Jun 2001 Location: Benton, AR "The Heart of Arkansas" Posts: 10,880	Re: bolt torque for ram horns. Make sure they're not warped.....it may be that they won't but then this note wouldn't matter. I have three sets of ram's horn exhaust manifolds that I need to identify. Any websites that anyone knows of right off the top of your head? __________________ Member Nr. 2770 '96 GMC Sportside; 4.3/SLT - Daily driven....constantly needs washed. '69 C-10 SWB; 350/TH400 - in limbo The older I get, the better I was.

09-28-2008, 10:02 PM	#5
68C15 blood type; Retumbo Join Date: Jan 2004 Location: next to my reloading bench Posts: 10,269	Re: bolt torque for ram horns. I would go for 20 ft.lbs. the manifolds grow as they heat up. if the bolts are too tight they will break and then the manifolds will be ruined from a major leak. also, do NOT use any gasket. at the most a light film of ultra copper RTV sealant.

09-29-2008, 06:05 AM	#7
68C15 blood type; Retumbo Join Date: Jan 2004 Location: next to my reloading bench Posts: 10,269	Re: bolt torque for ram horns. unless you use the 2 layered stainless steel ones from GM they will blow out.

10-01-2008, 07:15 AM	#12
truckdude239 Senior Member Join Date: Sep 2005 Location: Lewisville, Nc Posts: 10,238	Re: bolt torque for ram horns. umm i used gaskets with mine and have had no problems __________________ David fuller Ase Certified Mechanic Click here to help support our board!! 1971 Chevy c-10 under going a 4.8l LSx swap Build Thread http://67-72chevytrucks.com/vboard/s...d.php?t=421305 2007 Honda Accord my daily 145kmiles 2002 Honda Accord 4 door With 330k(sisters car) 2005 toyota Avalon 228k( brothers car) 2002 Sububran 5.3 245k 2000 Tahoe 5.3l 378 General manager for Marco's Carwash & lube

10-01-2008, 08:46 AM	#13
WorkinLonghorn Senior Member Join Date: Dec 2006 Location: Studio City, Calif. Posts: 2,886	Re: bolt torque for ram horns. Just for the record,the factory torque specs for the ram-horn exhaust manis is; 20 ft.lbs. for the outside bolts and 30 for the inside bolts. __________________ '69 GMC C2500 Custom Camper, 8 1/2' bed, New GM 350, NP 435 Close Ratio 4spd. Trans., 3.73 Dana-60 open.Camper and Trailer wiring, PS, PB, AC, tach , three gas tanks, stereo speakers, 2nd owner, Work-Truck supreme. Last edited by WorkinLonghorn; 10-01-2008 at 08:47 AM.

10-01-2008, 11:05 AM	#15
WorkinLonghorn Senior Member Join Date: Dec 2006 Location: Studio City, Calif. Posts: 2,886	Re: bolt torque for ram horns. I guess so. I do think that those specs are important though,just due to the heat involved. I over torqued mine before I got the specs and later I noticed a crack,and had to replace the mani. 5lbs over/under may be safe. __________________ '69 GMC C2500 Custom Camper, 8 1/2' bed, New GM 350, NP 435 Close Ratio 4spd. Trans., 3.73 Dana-60 open.Camper and Trailer wiring, PS, PB, AC, tach , three gas tanks, stereo speakers, 2nd owner, Work-Truck supreme.

10-01-2008, 11:07 AM	#16
justcuz Registered User Join Date: May 2008 Location: Alta Loma, Ca. Posts: 930	Re: bolt torque for ram horns. It won't hurt. If they don't leak don't sweat it. Just as an aside the intake manifold bolts torque to 35 ft. lbs. Even if the manifolds swell with heat the bolts will stretch a little too. I just drilled out the center holes in my sons 93 because they are almost impossible to get all the bolts in without extra movement. Funny the outers are 1/2 holes but the inners are 7/16, I drilled the inners to 1/2 also. I guess that is why a lot of 88 and up trucks crack exhaust manifolds.

10-01-2008, 08:55 PM	#18
68C15 blood type; Retumbo Join Date: Jan 2004 Location: next to my reloading bench Posts: 10,269	Re: bolt torque for ram horns. the center holes are smaller because that is what locates the manifold. the outter holes are bigger to allow the manifold to grow lengthwise. as far as the theory of the bolts and manifold both growing. they are made of different metals. the cast iron expands more under heat than steel.

10-01-2008, 09:04 PM	#19
72swbcamo Active Member Join Date: Dec 2003 Location: Waterbury, CT Posts: 591	Re: bolt torque for ram horns. The outer ports of the exhaust manifold have locking plates on them. After you install and torque the bolts you bend over the tabs on the locking plates to secure the bolts. I don't see any one mentioning them.

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