What would happen... - The 1947 - Present Chevrolet & GMC Truck Message Board Network

chevjayfsd · 11-26-2002, 04:50 PM

What would happen if i ran a big cam with a stock stall converter.... Would i lose power...
Would it be bad for the engine???
the lift on the cam is .487 and .490

larouchedem · 11-26-2002, 05:08 PM

chevjayfsd,

You may have to set idle speed pretty high and that'll cause drivetrain shock when you put it in gear. It'll be a slug out of the hole too, IF the cam has sufficient duration, esp if it is ground on tight lobe seperation.

Lift alone doesn't make for a high rpm cam.
Duration and lobe seperation angle affect
things too. What is your duration [at .050"]?
What is the lobe seperation [LSA]?

Btw - advancing the cam a few degrees will help low end.
Dave

[/i]
What would happen if i ran a big cam with a stock stall converter.... Would i lose power...
Would it be bad for the engine???
the lift on the cam is .487 and .490 [/QUOTE]

cableguy0 · 11-26-2002, 05:14 PM

we need to know the duration @.050 on that cam my guess is thats probably in the 230@.050 range or higher which u r gonna want at least a 2500 stall verter for. if the duration is that high u wont get that motor to idle for sh!t with the strock converter and it will be a total dog out of the hole

Ackattack · 11-26-2002, 05:17 PM

I was running a XE268 which I was told was the biggest I could run on a stock converter, and I'm sure it was, cause it idled pretty rough; much like what was descibed above. No I have the HE268 and it's pretty decent with the stock converter.

dion · 11-26-2002, 05:24 PM

I had a 2000-2000 stall with my cam, it wouldn't idle, was a dog off the line. I went with the 3000 stall and the truck runs great.

chevjayfsd · 11-26-2002, 05:32 PM

Ok heres another question.....What would happen if i ran a .462 and .469 lift cam then i installed a 3000 Stall converter???? Would it run better or run crappier??

Would that be too much stall for that cam??? or is there such a thing

larouchedem · 11-26-2002, 05:40 PM

chevjayfsd,

The looser the convertor is, the soggier the
part throttle low speed response will be.

Fwiw - I hate the feel of a loose convertor on the street at part throttle. I've run switch pitch convertors in every TH400 equipped vehicles that I've owned for 20 years or more. Nice and tight in low stall, and with the push of a button, they become a high stall. You can splice into the brake light circuit to allow them to go into high stall at the stop light to prevent creep too. It costs more to convert to switch pitch, but it's well worth it imo.

Do you know your specs that I asked about? What brand cam? Part # or grind #?
Dave

[/i]
Ok heres another question.....What would happen if i ran a .462 and .469 lift cam then i installed a 3000 Stall converter???? Would it run better or run crappier??

Would that be too much stall for that cam??? or is there such a thing [/QUOTE]

chevjayfsd · 11-26-2002, 05:50 PM

the cam specs are

Adv. Dur. Dur. @ .050 Lobe sep=110
Int/Exh. Int./Exh
262/270 218/224

Lift = 462/469

larouchedem · 11-26-2002, 07:58 PM

chevjayfsd,

I'm too lazy to look it up to be certain, but I'm pretty sure it's pretty close to the compcams HE268,except you have more exh duration. It should be ok w/a stock convertor unless you are geared really tall.
Dave

[/i]
the cam specs are

Adv. Dur. Dur. @ .050 Lobe sep=110
Int/Exh. Int./Exh
262/270 218/224

Lift = 462/469 [/QUOTE]

crazy longhorn · 11-26-2002, 08:08 PM

Shoot for an XE 268 comp(.477/.480, 224/230dur @.050). Go in the rangeof 2500 on the stall, it will run good with your 3.73 coggs. I run a TCI breakaway with the XE 268 comp(advertised stall 2400-2800)......still very streetable(will idle a little choppier in your 355). good luck....crazy AL

larouchedem · 11-26-2002, 08:25 PM

chevjayfsd,

Btw - If you have the cam, and your engine
isn't yet assembled, you could move the cam ahead so the centerlines are 106/114 instead of 110/110. That'll help low end if your budget will not allow a looser convertor. It'll make the engine snappier, esp if it is low compression. If it's no more than 8.5-1, I would probably move it ahead even more to 104/116 centers.
It your budget allows, the XE comp grinds do make great power for short duration cams, although I'd run roller rockers with them, as they have very fast ramps.
Dave Brode
[btw - it's larouchedem - Lyndon Larouche is a presidential candidate for '04, and I'm a dem.
I obviously will support him in '04]

[/i]
the cam specs are

Adv. Dur. Dur. @ .050 Lobe sep=110
Int/Exh. Int./Exh
262/270 218/224

Lift = 462/469 [/QUOTE]

crazy longhorn · 11-26-2002, 08:33 PM

im not runnin a roller rocker, but have the Comp roller tips....pretty nice combo with good street manners, but d@mn rough on tires

11-26-2002, 04:50 PM	#1
chevjayfsd Project 7dos Join Date: Aug 2001 Location: Abilene, Texas Posts: 876	What would happen... What would happen if i ran a big cam with a stock stall converter.... Would i lose power... Would it be bad for the engine??? the lift on the cam is .487 and .490 __________________ 7DOS - 1972 C-10 350/350 Porterbuilt/Accuair 20x8.5/20x10 Ride Low or Die PSSST - Yes it's bagged. 7dos build thread: http://67-72chevytrucks.com/vboard/s...d.php?t=610290

11-26-2002, 05:08 PM	#2
larouchedem Registered User Join Date: Nov 2002 Posts: 36	Re: What would happen... chevjayfsd, You may have to set idle speed pretty high and that'll cause drivetrain shock when you put it in gear. It'll be a slug out of the hole too, IF the cam has sufficient duration, esp if it is ground on tight lobe seperation. Lift alone doesn't make for a high rpm cam. Duration and lobe seperation angle affect things too. What is your duration [at .050"]? What is the lobe seperation [LSA]? Btw - advancing the cam a few degrees will help low end. Dave [/i] What would happen if i ran a big cam with a stock stall converter.... Would i lose power... Would it be bad for the engine??? the lift on the cam is .487 and .490 [/QUOTE]

11-26-2002, 05:14 PM	#3
cableguy0 Senior Member Join Date: Apr 2000 Location: Delta,Pa Posts: 14,948	we need to know the duration @.050 on that cam my guess is thats probably in the 230@.050 range or higher which u r gonna want at least a 2500 stall verter for. if the duration is that high u wont get that motor to idle for sh!t with the strock converter and it will be a total dog out of the hole __________________ Owner of North Point Car Care in Dundalk Md. We specialize in custom exhaust on both modern and classic vehicles. We are a full service auto shop from classics to modern vehicles. Feel free to contact me with questions. I will give a 10% discount to any board member.

11-26-2002, 05:17 PM	#4
Ackattack Senior Member Join Date: Aug 2002 Location: Valley Center KS Posts: 3,524	I was running a XE268 which I was told was the biggest I could run on a stock converter, and I'm sure it was, cause it idled pretty rough; much like what was descibed above. No I have the HE268 and it's pretty decent with the stock converter. __________________ Project Bruiser: 68 Pro-Touring C-10 5.3L / 4L60E Project Ironhide: 97 GMC Crew Cab 4x4 Cummins SOLD: '69 GMC 1/2T SWB TBI'd: Project No Buck Assembly Manual Index Sign up Thread!!! Factory Service Manual Index

11-26-2002, 05:24 PM	#5
dion 72 Cheyenne Join Date: Oct 2001 Location: San Diego Posts: 2,086	I had a 2000-2000 stall with my cam, it wouldn't idle, was a dog off the line. I went with the 3000 stall and the truck runs great. __________________ Burnout Idle 1972Cheyenne 1966/67Stouts

11-26-2002, 05:32 PM	#6
chevjayfsd Project 7dos Join Date: Aug 2001 Location: Abilene, Texas Posts: 876	Ok heres another question.....What would happen if i ran a .462 and .469 lift cam then i installed a 3000 Stall converter???? Would it run better or run crappier?? Would that be too much stall for that cam??? or is there such a thing __________________ 7DOS - 1972 C-10 350/350 Porterbuilt/Accuair 20x8.5/20x10 Ride Low or Die PSSST - Yes it's bagged. 7dos build thread: http://67-72chevytrucks.com/vboard/s...d.php?t=610290

11-26-2002, 05:40 PM	#7
larouchedem Registered User Join Date: Nov 2002 Posts: 36	chevjayfsd, The looser the convertor is, the soggier the part throttle low speed response will be. Fwiw - I hate the feel of a loose convertor on the street at part throttle. I've run switch pitch convertors in every TH400 equipped vehicles that I've owned for 20 years or more. Nice and tight in low stall, and with the push of a button, they become a high stall. You can splice into the brake light circuit to allow them to go into high stall at the stop light to prevent creep too. It costs more to convert to switch pitch, but it's well worth it imo. Do you know your specs that I asked about? What brand cam? Part # or grind #? Dave [/i] Ok heres another question.....What would happen if i ran a .462 and .469 lift cam then i installed a 3000 Stall converter???? Would it run better or run crappier?? Would that be too much stall for that cam??? or is there such a thing [/QUOTE]

11-26-2002, 05:50 PM	#8
chevjayfsd Project 7dos Join Date: Aug 2001 Location: Abilene, Texas Posts: 876	Larouchadem (hope thats right) HEHE the cam specs are Adv. Dur. Dur. @ .050 Lobe sep=110 Int/Exh. Int./Exh 262/270 218/224 Lift = 462/469 __________________ 7DOS - 1972 C-10 350/350 Porterbuilt/Accuair 20x8.5/20x10 Ride Low or Die PSSST - Yes it's bagged. 7dos build thread: http://67-72chevytrucks.com/vboard/s...d.php?t=610290

11-26-2002, 07:58 PM	#9
larouchedem Registered User Join Date: Nov 2002 Posts: 36	Re: Larouchadem (hope thats right) HEHE chevjayfsd, I'm too lazy to look it up to be certain, but I'm pretty sure it's pretty close to the compcams HE268,except you have more exh duration. It should be ok w/a stock convertor unless you are geared really tall. Dave [/i] the cam specs are Adv. Dur. Dur. @ .050 Lobe sep=110 Int/Exh. Int./Exh 262/270 218/224 Lift = 462/469 [/QUOTE]

11-26-2002, 08:08 PM	#10
crazy longhorn Fabricate till you "puke" Join Date: Jun 2002 Location: Ill Posts: 9,402	Shoot for an XE 268 comp(.477/.480, 224/230dur @.050). Go in the rangeof 2500 on the stall, it will run good with your 3.73 coggs. I run a TCI breakaway with the XE 268 comp(advertised stall 2400-2800)......still very streetable(will idle a little choppier in your 355). good luck....crazy AL __________________ 69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears....

11-26-2002, 08:25 PM	#11
larouchedem Registered User Join Date: Nov 2002 Posts: 36	Re: Larouchadem (hope thats right) HEHE chevjayfsd, Btw - If you have the cam, and your engine isn't yet assembled, you could move the cam ahead so the centerlines are 106/114 instead of 110/110. That'll help low end if your budget will not allow a looser convertor. It'll make the engine snappier, esp if it is low compression. If it's no more than 8.5-1, I would probably move it ahead even more to 104/116 centers. It your budget allows, the XE comp grinds do make great power for short duration cams, although I'd run roller rockers with them, as they have very fast ramps. Dave Brode [btw - it's larouchedem - Lyndon Larouche is a presidential candidate for '04, and I'm a dem. I obviously will support him in '04] [/i] the cam specs are Adv. Dur. Dur. @ .050 Lobe sep=110 Int/Exh. Int./Exh 262/270 218/224 Lift = 462/469 [/QUOTE]

11-26-2002, 08:33 PM	#12
crazy longhorn Fabricate till you "puke" Join Date: Jun 2002 Location: Ill Posts: 9,402	im not runnin a roller rocker, but have the Comp roller tips....pretty nice combo with good street manners, but d@mn rough on tires __________________ 69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears....



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