ID'ing a 350 Cam

[5Tractorguy]

Is there any way to ID a cam if you remove the intake manifold or timing chain cover? Do they stamp the info on them somewhere?

Dad had one installed in a 350 years ago and we can't for the life of us remember what it was. We know the builder "installed a towing cam", but the specs are unknown.

[Ziegelsteinfaust]

There is typically a part number under the timing gear.

Sometimes you can cross check it on Google, and do sometimes its a generic rv cam or rebuilders special. So it likely won't be listed anywhere.

[5Tractorguy]

Originally Posted by Ziegelsteinfaust

There is typically a part number under the timing gear.

Sometimes you can cross check it on Google, and do sometimes its a generic rv cam or rebuilders special. So it likely won't be listed anywhere.

Thanks, I'll pull the timing gear first and check. Worst case, it's getting a new cam.

[Nick_R_23]

Usually there’s a number engraved on the back of the cam, which means you’ll have to remove the cam to see it.

[5Tractorguy]

Originally Posted by Nick_R_23

Usually there’s a number engraved on the back of the cam, which means you’ll have to remove the cam to see it.

Shoot... well I figured one way or another it may have to get completely removed to ID or replace. I'll start with the timing gear and work my way back!

[SCOTI]

The ID numbers are usually stamped on the front or rear 'face' of the cam. The timing gear can be removed from the front & theres a galley plug on the rear that can be removed & replaced (basically a freeze plug for the cam galley).

That being said..... Even w/the numbers, you may/may-not be able to positively ID the cam. I did this on a gifted 406 a while back. The numbers were on the rear of the cam but matched nothing I found on the internet. I spoke to a guy that had his motor built from the gentleman I got the 406 from & he told me what the cam was because they discussed it when determining what to use on his motor. When I looked up that 'current' specific grind, the numbers don't match.

[cadillac_al]

I'm sure it's just a run of the mill RV/towing cam; .450ish lift and 215-220 duration @ .050". If it is working fine I would leave it alone unless you need more power.

[5Tractorguy]

Originally Posted by SCOTI

The ID numbers are usually stamped on the front or rear 'face' of the cam. The timing gear can be removed from the front & theres a galley plug on the rear that can be removed & replaced (basically a freeze plug for the cam galley).

That being said..... Even w/the numbers, you may/may-not be able to positively ID the cam. I did this on a gifted 406 a while back. The numbers were on the rear of the cam but matched nothing I found on the internet. I spoke to a guy that had his motor built from the gentleman I got the 406 from & he told me what the cam was because they discussed it when determining what to use on his motor. When I looked up that 'current' specific grind, the numbers don't match.

Unfortunately this engine is still in the truck so everything has to be pulled out the front. I was thinking about that too, if the numbers would even be searchable online if found. Thought about calling the rebuilder too since he's still at it, but after 15yrs+/- I doubt he'll remember what was done to it.

Originally Posted by cadillac_al

I'm sure it's just a run of the mill RV/towing cam; .450ish lift and 215-220 duration @ .050". If it is working fine I would leave it alone unless you need more power.

Well, I like to leave it be, trust me! Reason for the inquiry is it's an '88 TBI engine. From what I discovered online, you have to reprogram the ECM chip when a cam is installed. When dad restored this truck and it went on the road in 2011, it never ran/has never run right. I've posted a mess of threads on here over the years trying to figure it out, replaced every sensor, been through 4 ECM's and 2 throttle bodies, ETC.

After stumbling upon that info online, everything made sense. Figured if I can ID the cam and have the PROM done, that would be great. But if I can't ID the cam, it's getting a stock 350 TBI cam so I don't have to touch the computer. Been a 10yr long headache to say the least...

[Ziegelsteinfaust]

If it's going in a tbi engine I would order a brand new one, and have a chip burnt from new specs.

Cam specs change over the years and quite often use the same.part number. Even though a older version has been superceded. Changes are often minor but with old FI it maybe enough to throw out some issues.

I am a fan of the Duntov 30-30 cam for its superior deivibilty 🤫. 20 odd years ago I read a article on reproduction cams in a circle track magazine. From something like 10 different manufacturers making the claimed same cam. There was a decent variance between all the cams. Rather it be lift, duration, or LSA. And that doesn't factor in ramp specs that are different too. As measured by the magazine writer.

[Nick_R_23]

For a TBI engine, do yourself a favor and throw a stock cam back in there. The ECU parameters are too picky, and the TBI chips are a toss up at best. Not worth the headache for something that won’t give you much extra power anyway. At most, the changeover to a Caprice TBI roller cam would be as far as I would go, provided the block has the provisions to do so.

[5Tractorguy]

Thanks for the additional info guys!

So this engine is in an '88 V30 dump truck. Dad had a cam put in for extra power towing and hauling not knowing about the ECM deal...

Currently has an ECM and throttle body from his old 1991 Cheyenne 2500 (GMT400 truck). Would a stock cam for a '91 350 be correct? Or will any stock cam '87 - '91 work? Not sure if GM changed ECM parameters over those years, or kept them all the same. Or if being from a GMT400 would make a difference. I also have a few more computers kicking around from the late 80's.

Searching online I found Harristuning.com, figured he would be the best place to have a chip burnt if necessary...

Is this the 30-30 cam you mentioned? https://www.summitracing.com/parts/cca-12-673-4

I'm not very knowledgeable when it comes to this stuff so any more info you guys have would be appreciated. Looking to get this truck running correctly the simplest way possible. More than happy with stock power at this point since it's probably had half that at best it's whole life...

Swapping out the cam with a stock, correct new one and NOT having to touch the computer chip would be preferred.

[SCOTI]

Originally Posted by 5Tractorguy

Thanks for the additional info guys!

So this engine is in an '88 V30 dump truck. Dad had a cam put in for extra power towing and hauling not knowing about the ECM deal...

Currently has an ECM and throttle body from his old 1991 Cheyenne 2500 (GMT400 truck). Would a stock cam for a '91 350 be correct? Or will any stock cam '87 - '91 work? Not sure if GM changed ECM parameters over those years, or kept them all the same. Or if being from a GMT400 would make a difference. I also have a few more computers kicking around from the late 80's.

Searching online I found Harristuning.com, figured he would be the best place to have a chip burnt if necessary...

Is this the 30-30 cam you mentioned? https://www.summitracing.com/parts/cca-12-673-4

I'm not very knowledgeable when it comes to this stuff so any more info you guys have would be appreciated. Looking to get this truck running correctly the simplest way possible. More than happy with stock power at this point since it's probably had half that at best it's whole life...

Swapping out the cam with a stock, correct new one and NOT having to touch the computer chip would be preferred.

I did a 'Mild/RV/Towing' cam for the TBI fueled rebuilt 7.4l in my Squarebody 89 dually. TBIChips/Harris Tuning is where my chip came from. I didn't have exact cam specs for them (that I recall) & just told them it was just a towing/RV cam. Other than some mild surging @ idle I haven't had issues on my TBI set-up. They have a required tech sheet where you input as much info as possible & the chip is burned off of that. I expected to use that as a starting point & possibly seek further tuning beyond that & quickly found.... nothing. Nobody does tuning for these antiquated set-ups that I could find locally.

It's still in there as is. 7500miles or so on the rebuilt motor & it works. I know there is more in the combo but live w/it as is.

[5Tractorguy]

Alrighty, I called Harris tuning and he does need the specs to burn a chip for the current cam. And since I don't know what those are, I'm going to install a stock cam and be done with it.

Does anyone know the correct duration for a stock 350 TBI cam? I looked through summit quick and they have a mess of stock replacement cams, all with different durations... Just want to make sure I get the right one the first time!

[Dead Parrot]

If you have to replace the cam anyway, might ask Harris Tuning if they have a cam recommendation for your application for which they already have a proven chip burn set.

[SCOTI]

Originally Posted by Dead Parrot

If you have to replace the cam anyway, might ask Harris Tuning if they have a cam recommendation for your application for which they already have a proven chip burn set.

They should.

[Nick_R_23]

I’d advise against getting anything from Harris Tuning.

[5Tractorguy]

I called again and he said you only pick up 25hp with a Summit cam (forgot what cam, step above stock).

Apparently (according to Harris) the stock cam duration at .050 is 165 Exhaust and 175 Intake. But I'll be darned if I can find that duration anywhere for sale, Jegs or Summit...

Anyways, I have to track down a stock cam. Not going to take the chip route...
This one comes up on Summit, the only stock one I can find on there.

https://www.summitracing.com/parts/m.../v30/year/1988

Called Comp Cams too. The smallest duration they have is 206/212 and according to the tech guy that's about equivalent to an RV cam, unfortunately...