Camshaft
Thread Starter
Heel & Toe
Joined: Aug 2022
Posts: 20
Likes: 7
From: Maryland
Camshaft
Looking at upgrading the camshaft in my 85 at some point. I’m going to get rid of the current heads for Aluminum ones, as well as probably go with a superram. My auto tech teacher told me to buy a GM 3896962 camshaft. Can’t really find much information on them. He said he ran them in a lot of pretty strong motors back in the day, but I can’t really find too much information about them. I’m going to swap the intake and heads first, so I have plenty time to think over the camshaft selection. If anyone has information about the 3896962 cam Id appreciate it. Alternatives etc. If it’s a solid quality cam I’d like to have it, as they only cost around $300.
Team Owner
Joined: Sep 2001
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
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You have a flat tappet cam stock, but I'd convert to roller and open up my options.
That said, on a 350, something around 220/220 @050" would be about right for the SR. You will need a custom chip done, which on an 85 can be more difficult to get done.
What he recommended is not that far off, google is your friend. Chevrolet Performance 3896962 Chevrolet Performance Hydraulic Flat Tappet Camshafts | Summit Racing
That said, on a 350, something around 220/220 @050" would be about right for the SR. You will need a custom chip done, which on an 85 can be more difficult to get done.
What he recommended is not that far off, google is your friend. Chevrolet Performance 3896962 Chevrolet Performance Hydraulic Flat Tappet Camshafts | Summit Racing
Pro
Joined: Oct 2004
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From: Melbourne Victoria
Team Owner
Joined: Sep 2001
Posts: 62,140
Likes: 1,728
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Le Mans Master
Joined: Aug 2015
Posts: 6,090
Likes: 1,972
From: St. Charles MO
I'd look at the Comp Cams XFI 218/224 cam, except I'd probably ask if they can grind one with a 110-deg lobe separation angle instead of the 113 it comes with. This would give you a somewhat choppy idle, but it would be a very midrange-focused cam that should compliment stock heads and a SuperRam intake very well. It has fast ramp rates and significant overlap to help with that. You definitely need to be able to tune your ECM to go with any serious cam and intake upgrade.
Thread Starter
Heel & Toe
Joined: Aug 2022
Posts: 20
Likes: 7
From: Maryland
[QUOTE=MatthewMiller;1605895582]
Im going to be upgrading the heads. Probably going with Edelbrock E-Street Heads 5089. I know I have to tune the ECU. Big drawback with the 85, 86+ had better ECU’s from what I’ve read. Swapping to an 86 doesn’t seem to expensive though.
Edit: Also trying to stick with a flat tappet cam. keeps costs down a little. Will probably switch over to roller in the future.
Im going to be upgrading the heads. Probably going with Edelbrock E-Street Heads 5089. I know I have to tune the ECU. Big drawback with the 85, 86+ had better ECU’s from what I’ve read. Swapping to an 86 doesn’t seem to expensive though.
Edit: Also trying to stick with a flat tappet cam. keeps costs down a little. Will probably switch over to roller in the future.
Le Mans Master
Joined: Aug 2015
Posts: 6,090
Likes: 1,972
From: St. Charles MO
[QUOTE=halman1412;1605895794]
The beautiful thing about a cam with fairly short duration and lots of overlap is that if you use better flowing heads, the top end opens up more but you don't lose significant low end. My 396 with really good heads used nearly the same cam specs as what I recommended and it pull hard from 2000-6000 and easily kept going up to its 6400rpm redline. So better heads is even better. You could arguably use a little more LSA with better heads, which would make the idle less choppy and extend the top end a bit more, but you'd lose some midrange grunt by doing that. Comp Cams makes some flat tappet XFI cams, so I'd shop their catalog and try to get something close to the specs I recommended. I'm sure they'll have less aggressive ramps, but they will still make good power.
Im going to be upgrading the heads. Probably going with Edelbrock E-Street Heads 5089. I know I have to tune the ECU. Big drawback with the 85, 86+ had better ECU’s from what I’ve read. Swapping to an 86 doesn’t seem to expensive though.
Edit: Also trying to stick with a flat tappet cam. keeps costs down a little. Will probably switch over to roller in the future.
Edit: Also trying to stick with a flat tappet cam. keeps costs down a little. Will probably switch over to roller in the future.
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Burning Brakes
Joined: Sep 2017
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rollers have no chance of cam going flat, don't need high zinc oil. but flat tappet cam can have faster ramps 270 and under advertised duration. Howards sells flat tappet cams they guarantee not to go flat. comp cams sells treated camshafts
Le Mans Master
Joined: Sep 2006
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From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
Cam swap
Uh you really need to do everything at once.
to do a cam swap, the intake has to come back off.
PITA with replacing injector o rings and scraping gasket material off heads, then disconnecting fuel lines & replacing orings, etc.
on the ecu, you will have to change the engine wire harness. The maf module that your ecu uses is external, while 86 and up is in the ecu.
to do a cam swap, the intake has to come back off.
PITA with replacing injector o rings and scraping gasket material off heads, then disconnecting fuel lines & replacing orings, etc.
on the ecu, you will have to change the engine wire harness. The maf module that your ecu uses is external, while 86 and up is in the ecu.
Last edited by coupeguy2001; Nov 27, 2022 at 09:25 AM.
Safety Car
Joined: Oct 2007
Posts: 4,204
Likes: 1,074
From: South Florida
whatever you do,
don't use a high lift,
don't use a fast ramp camshaft
Avoid comp cams
Stick to GM imo, cams that work with nearly stock springs
Slow ramps + light springs + low lift = longevity & valve control
don't use a high lift,
don't use a fast ramp camshaft
Avoid comp cams
Stick to GM imo, cams that work with nearly stock springs
Slow ramps + light springs + low lift = longevity & valve control
Burning Brakes
Joined: Mar 2010
Posts: 1,094
Likes: 68
From: Providence RI
do you have any idea how much work it is to swap cams?
Thread Starter
Heel & Toe
Joined: Aug 2022
Posts: 20
Likes: 7
From: Maryland
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Haven’t been on this thread in a while. Ended up buying 3896962 Cam. My intake manifold gaskets shat themselves so I figured F it while i’m in there might as well. Appreciate all the recs and advice from y’all. Got the car apart right now about 75% of the way apart. Let y’all know how it drives afterwards.
Advanced
Joined: Oct 2020
Posts: 68
Likes: 11
From: Oscoda, Michigan
Yes, let us know.
Haven’t been on this thread in a while. Ended up buying 3896962 Cam. My intake manifold gaskets shat themselves so I figured F it while i’m in there might as well. Appreciate all the recs and advice from y’all. Got the car apart right now about 75% of the way apart. Let y’all know how it drives afterwards.
Yes! let us know how it goes. My '87 Is getting a SuperRam, cam, heads and headers soon.
Advanced
Joined: Oct 2020
Posts: 68
Likes: 11
From: Oscoda, Michigan
Thread Starter
Heel & Toe
Joined: Aug 2022
Posts: 20
Likes: 7
From: Maryland
Got the cam in, put Rhoades lifters in to go with it. Naturally some jackass in an F-150 ran into me in the parking lot of my high school the day after. Thank god it wasn't a silverado, might've actually done some damage. Car runs great though. Even with the garbage stock iron heads, seems like i gained a fair bit of power up top, and some torque down low. Pretty happy with it, considering the cam and lifters only ran me about $500. Hope insurance writes me a big enough check to cover damage and some more parts.
Advanced
Joined: Oct 2020
Posts: 68
Likes: 11
From: Oscoda, Michigan
Here are some notes for you. After a year of planning, decisions (thank you, TPIS), and collecting parts, the horsepower project is almost done. I thought it was ridiculous that my '87 Corvette C4 350 cid engine made less than 300 horsepower. The parts are a SuperRam intake, Air Flow Research 195cc SBC Street Port Aluminum Heads, ZZ409 Hydraulic Roller Camshaft .520" lift, 226 single duration pattern, and exhaust headers.