Cam shaft help!!!! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

SLDPULR · 12-23-2016, 09:47 PM

Dear friends and fellow truck nuts. I am in need of some help. I built a motor for my 1969 C10 that was going to be a pro street build. About half way through the build someone made me a offer to buy the truck that I could not refuse. I ended up buying a beautiful 1980 square body and I would like to put the motor I originally built for the pro street truck in the new 1980 but I need to tone down the cam.

The cam that is currently in the motor is a comp cams XE294H. It needs a 3300+ stall converter and in my opinion is to much for a truck that I would like to drive on a regular basis.

The 1980 has a Turbo 350C (electric lock up) in it and I bought a 2500 stall hughes converter. I will list out all my motor info and if you guys could help point me in the right direction I would greatly appreciate it.

I would like the truck to have the most power possible but still be streetable. This is a toy so I do not really care about fuel mileage. I would like a decent amount of lope if possible. Thanks guys and MERRY CHRISTMAS!

VEHICLE: 1980 SINGLE CAB SHORT BED
TRANS: TH350C WITH A 2500 STALL CONVERTER
GEARS: 3.73
MOTOR: 383CI, 10.3:1 COMP RATIO
HEADS: 190 RUNNERS 72CC CHAMBERS
INTAKE: RPM AIRGAP
CARB: 750 HOLLEY DOUBLE PUMPER

**Captainfab** · 12-24-2016, 01:25 AM

With that high of a static compression, you will want to be careful going with a smaller cam that may create too high of cylinder pressure for pump gas. I don't think I would go any smaller than the XE268H, and that may be too small. Maybe the XE274 or XE284.

'63GENIII · 12-24-2016, 01:50 AM

Would a narrower LSA help with keeping the dynamic compression in check? Not saying that I know anything about cams, just curious and trying to learn.

crazy longhorn · 12-24-2016, 02:20 AM

Quote:

Originally Posted by Captainfab

With that high of a static compression, you will want to be careful going with a smaller cam that may create too high of cylinder pressure for pump gas. I don't think I would go any smaller than the XE268H, and that may be too small. Maybe the XE274 or XE284.

Thanks Capt , to be the 1 st post....I do agree, with the ratio,I feel that an Xe-284 would do the work

Longhorn

geezer#99 · 12-24-2016, 10:23 AM

A little info to feed the fire.
http://www.crankshaftcoalition.com/w..._compatibility

hjewell2 · 12-25-2016, 06:28 PM

Quote:

Originally Posted by '63GENIII

Would a narrower LSA help with keeping the dynamic compression in check? Not saying that I know anything about cams, just curious and trying to learn.

Yes it will like a 106 or 108 LSA high cranking pressure low running pressure

'63GENIII · 12-26-2016, 01:17 AM

Thanks Geezer. Good read there.

SLDPULR · 12-26-2016, 07:30 PM

I think im going to go with the 284. The 2500 stall will match that a lot better and the power will come on closer to the right spot than the 294.

geezer#99 · 12-26-2016, 07:49 PM

Before you go swapping cams, what's your timing set up like?
What's initial?
How much in the mechanical?

SLDPULR · 12-26-2016, 08:16 PM

Quote:

Originally Posted by geezer#99

Before you go swapping cams, what's your timing set up like?
What's initial?
How much in the mechanical?

It's currently zero. I haven't put the motor in the truck yet. I had it at 30 in the old truck but I never drove it so not sure what it would behave like in drive.

SLDPULR · 12-26-2016, 08:18 PM

The motor only has a few hours on it from letting it idle and breaking it in. Im ready to get this thing under the hood. Im just so on the fence about the cam. Id love to keep it cause the idle sounds pretty mean.

If I do keep the cam I will deff need help tuning the carb. Ive got a AFR gauge to put in the truck once I get it installed. I figured that would help with the jets and setting the idle mixture.

geezer#99 · 12-26-2016, 08:24 PM

Looks like you're over-thinking it!
Put it in and then fine tune it and if you got a problem then it's not hard to swap out a cam.

**Ironangel** · 12-26-2016, 10:46 PM

Quote:

Originally Posted by SLDPULR

Ive got a AFR gauge to put in the truck once I get it installed. I figured that would help with the jets and setting the idle mixture.

I'm interested in that AFR gauge, how does it get it reading? O2 sensor? I'm assuming it's a digital gauge?

SLDPULR · 12-26-2016, 10:48 PM

Quote:

Originally Posted by Ironangel

I'm interested in that AFR gauge, how does it get it reading? O2 sensor? I'm assuming it's a digital gauge?

It runs off a 02 sensor in the header and lets you know if your running rich or lean

geezer#99 · 12-27-2016, 12:55 AM

[QUOTE=SLDPULR;7805890]The motor only has a few hours on it from letting it idle and breaking it in. Im ready to get this thing under the hood. Im just so on the fence about the cam. Id love to keep it cause the idle sounds pretty mean.

If I do keep the cam I will deff need help tuning the carb. Ive got a AFR gauge to put in the truck once I get it installed. I figured that would help with the jets and setting the idle mixture.[/QUOTE

Tuning the carb likely will only be a power valve change.
Best tuning is done with the timing.
Then 99% of the time the carb is almost spot on.

12-23-2016, 09:47 PM	#1
SLDPULR Registered User Join Date: Apr 2014 Location: Oklahoma City Posts: 118	Cam shaft help!!!! Dear friends and fellow truck nuts. I am in need of some help. I built a motor for my 1969 C10 that was going to be a pro street build. About half way through the build someone made me a offer to buy the truck that I could not refuse. I ended up buying a beautiful 1980 square body and I would like to put the motor I originally built for the pro street truck in the new 1980 but I need to tone down the cam. The cam that is currently in the motor is a comp cams XE294H. It needs a 3300+ stall converter and in my opinion is to much for a truck that I would like to drive on a regular basis. The 1980 has a Turbo 350C (electric lock up) in it and I bought a 2500 stall hughes converter. I will list out all my motor info and if you guys could help point me in the right direction I would greatly appreciate it. I would like the truck to have the most power possible but still be streetable. This is a toy so I do not really care about fuel mileage. I would like a decent amount of lope if possible. Thanks guys and MERRY CHRISTMAS! VEHICLE: 1980 SINGLE CAB SHORT BED TRANS: TH350C WITH A 2500 STALL CONVERTER GEARS: 3.73 MOTOR: 383CI, 10.3:1 COMP RATIO HEADS: 190 RUNNERS 72CC CHAMBERS INTAKE: RPM AIRGAP CARB: 750 HOLLEY DOUBLE PUMPER __________________ 1980 TURBO C10 (GRUMPYC10 ON INSTAGRAM FOR MORE PICTURES)

12-24-2016, 01:25 AM	#2
Captainfab 60-66 Nut Join Date: Mar 2007 Location: Coeur d'Alene, Idaho Posts: 23,254	Re: Cam shaft help!!!! With that high of a static compression, you will want to be careful going with a smaller cam that may create too high of cylinder pressure for pump gas. I don't think I would go any smaller than the XE268H, and that may be too small. Maybe the XE274 or XE284. __________________ Power Steering Box Adapter Plates For Sale HERE Power Brake Booster Adapter Brackets For Sale '63-'66 HERE and '67-'72 HERE and '60-'62 HERE and "60-'62 with clutch HERE Rear Disc Brake Brackets For Sale. Impala SS calipers HERE Camaro Calipers HERE D52 Calipers HERE 6 Lug HERE Hydroboost Mounting Plates HERE

12-24-2016, 01:50 AM	#3
'63GENIII Registered User Join Date: Sep 2008 Location: San Carlos, Ca. Posts: 3,048	Re: Cam shaft help!!!! Would a narrower LSA help with keeping the dynamic compression in check? Not saying that I know anything about cams, just curious and trying to learn. __________________ Chris '63 k15 long step Vortec 7.4 - L29 Blackbear tune, Five 0 Motorsports injectors, Chris Straub Cam, NV4500, divorced 205 52" front and 63" rear spring swap D44 / 14bff - disc axles Milemarker 9K and 10.5K hydraulic winches 63" & B52 Spring Install http://67-72chevytrucks.com/vboard/s...ng+swap+thread NV4500 Reverse Build Thread http://67-72chevytrucks.com/vboard/s...=reverse+build L29 - 7.4 Vortec Build http://67-72chevytrucks.com/vboard/s...&highlight=L29

12-24-2016, 10:23 AM	#5
geezer#99 Registered User Join Date: Aug 2009 Location: Bowser Posts: 13,785	Re: Cam shaft help!!!! A little info to feed the fire. http://www.crankshaftcoalition.com/w..._compatibility

12-26-2016, 01:17 AM	#7
'63GENIII Registered User Join Date: Sep 2008 Location: San Carlos, Ca. Posts: 3,048	Re: Cam shaft help!!!! Thanks Geezer. Good read there. __________________ Chris '63 k15 long step Vortec 7.4 - L29 Blackbear tune, Five 0 Motorsports injectors, Chris Straub Cam, NV4500, divorced 205 52" front and 63" rear spring swap D44 / 14bff - disc axles Milemarker 9K and 10.5K hydraulic winches 63" & B52 Spring Install http://67-72chevytrucks.com/vboard/s...ng+swap+thread NV4500 Reverse Build Thread http://67-72chevytrucks.com/vboard/s...=reverse+build L29 - 7.4 Vortec Build http://67-72chevytrucks.com/vboard/s...&highlight=L29

12-26-2016, 07:30 PM	#8
SLDPULR Registered User Join Date: Apr 2014 Location: Oklahoma City Posts: 118	Re: Cam shaft help!!!! I think im going to go with the 284. The 2500 stall will match that a lot better and the power will come on closer to the right spot than the 294. __________________ 1980 TURBO C10 (GRUMPYC10 ON INSTAGRAM FOR MORE PICTURES)

12-26-2016, 07:49 PM	#9
geezer#99 Registered User Join Date: Aug 2009 Location: Bowser Posts: 13,785	Re: Cam shaft help!!!! Before you go swapping cams, what's your timing set up like? What's initial? How much in the mechanical?

12-26-2016, 08:18 PM	#11
SLDPULR Registered User Join Date: Apr 2014 Location: Oklahoma City Posts: 118	Re: Cam shaft help!!!! The motor only has a few hours on it from letting it idle and breaking it in. Im ready to get this thing under the hood. Im just so on the fence about the cam. Id love to keep it cause the idle sounds pretty mean. If I do keep the cam I will deff need help tuning the carb. Ive got a AFR gauge to put in the truck once I get it installed. I figured that would help with the jets and setting the idle mixture. __________________ 1980 TURBO C10 (GRUMPYC10 ON INSTAGRAM FOR MORE PICTURES)

12-26-2016, 08:24 PM	#12
geezer#99 Registered User Join Date: Aug 2009 Location: Bowser Posts: 13,785	Re: Cam shaft help!!!! Looks like you're over-thinking it! Put it in and then fine tune it and if you got a problem then it's not hard to swap out a cam.

12-27-2016, 12:55 AM	#15
geezer#99 Registered User Join Date: Aug 2009 Location: Bowser Posts: 13,785	Re: Cam shaft help!!!! [QUOTE=SLDPULR;7805890]The motor only has a few hours on it from letting it idle and breaking it in. Im ready to get this thing under the hood. Im just so on the fence about the cam. Id love to keep it cause the idle sounds pretty mean. If I do keep the cam I will deff need help tuning the carb. Ive got a AFR gauge to put in the truck once I get it installed. I figured that would help with the jets and setting the idle mixture.[/QUOTE Tuning the carb likely will only be a power valve change. Best tuning is done with the timing. Then 99% of the time the carb is almost spot on.



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