How do I identify an unknown camshaft without removing it from the motor ?

Tynan918

Royal Smart Person
Thread starter
Aug 2, 2021
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The best way to nail my correct timing and everything else related to tuning my engine correctly, is to know exactly what camshaft I'm working with..

I have an unknown camshaft and I want to identify it without pulling the camshaft from the motor..

What are you guys' ideas on how to go about that?

I seen this ProForm universal cam checker..part # 68902... what do you guys think about this?
Screenshot_20220911-084004-485.png


 

Tynan918

Royal Smart Person
Thread starter
Aug 2, 2021
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If the mill starts on the key with little persuasion from the acc pedal and idles nicely and smoothly, and shuts off without dieseling or running on, then your vacuum ought to be about where it should be.
It starts with a little persuasion from the gas pedal and seems to idle nicely and smoothly if you don't count the ticking.. depending on how my timing is set depends on if it diesels or not..

It diesels right now because I played with the timing yesterday but before I played with the timing it wasn't dieseling.. but it seems like I lost power when it wasn't dieseling...

I really need to adjust my vacuum canister because I have it turned all the way in and it's still giving me 24° advance when I connect it to the full manifold vacuum source on the carburetor.

My vacuum storage canister ball is also disconnected.. because I have no AC and I don't use cruise control, but would that cause a loss in vacuum ?
 

SSMonteMan

Greasemonkey
Jun 12, 2015
106
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From what I've seen of your build so far I'll put my money on it being a stock 88-95 truck cam.

Figure your ticking out first. Could be a major issue leading to total engine failure. Could also be an exhaust leak.
 
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Tynan918

Royal Smart Person
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Aug 2, 2021
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From what I've seen of your build so far I'll put my money on it being a stock 88-95 truck cam.

Figure your ticking out first. Could be a major issue leading to total engine failure. Could also be an exhaust leak.
Very highly possible...the casting numbers show 83-84 LG4 305, head casting numbers show HO heads, and it was said to be pulled from a C10 pickup, which is why you see the serpentine setup.

What was the difference between the stock car camshaft for 305 and the truck camshaft for 305 ?
 

ck80

Comic Book Super Hero
Feb 18, 2014
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Very highly possible...the casting numbers show 83-84 LG4 305, head casting numbers show HO heads, and it was said to be pulled from a C10 pickup, which is why you see the serpentine setup.

What was the difference between the stock car camshaft for 305 and the truck camshaft for 305 ?
For what it's worth, again it sounds like you're caught in the old 'prior owner told me s'

Serpentine setups can be swapped from newer motors to older ones, certainly.

However, trucks didn't get serpentine belt factory until 1988. If the belt setup is on there because it was what came in the truck, it'd be a 1988-up truck. But in 1987 gm trucks went TBI, and, the factory TBI intake needed center bolt heads, not perimeter bolt heads, in order for the angle/pattern of the intake bolts to fit and clamp down properly.

You quite clearly have perimeter bolt heads.

Now, yes, it's possible that someone stuffed a carb 305 into the place of a tbi truck engine, but, they'd have killed off all their computer stuff and made their life a PITA which, to be honest, wouldn't seem worth it for a 305 swap -.they would've needed to do a carb, pressure regulator, tps kit, rpm signal to the trans because it came electronic signal controlled, intake, gaskets etc. Doable, yes, but anyone I heard about spending that much extra went for 350s or bigger, not 305s.

So, yes, I'm thinking you have fallen into the rabbit hole of a 'prior owner told me' or, that engine has been buggered by multiple 'I'm gonna built me a hut rud' types before you got it.

I'd ignore anything anyone told me about it before you got it, and just methodically verify everything you reasonably can on your own.
 
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86LK

Royal Smart Person
Jul 23, 2018
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the head casting #'s show HO heads? one thing for sure is they are pre-87 as:
1) no roller-tip rockers
2) perimeter clamp valve covers

and you said it is a circa '84 block which means 2pc rear main seal. and you can retro-fit the serpentine setup. I know, I've got one in the garage with what is possibly a "high nickel" block from the '70s (but still need to confirm that. the "high nickel" phrase is also considered a myth. meh, whatever)

 

SSMonteMan

Greasemonkey
Jun 12, 2015
106
43
Very highly possible...the casting numbers show 83-84 LG4 305, head casting numbers show HO heads, and it was said to be pulled from a C10 pickup, which is why you see the serpentine setup.

What was the difference between the stock car camshaft for 305 and the truck camshaft for 305 ?
I don't know the specs on the truck cam but they're not great. Good for low end torque and towing, sh*t for everything else.

I agree with the others in this thread. If you really want to know what you have, you're going to have to pull the cam and see if it's marked. I would bet it's not marked and therefore a stock cam.

Verify you don't have an exhaust leak first! Because I'm going to recommend something here that's going to cost more money...

If you're going to pull the cam, don't put it back in. Go ahead and get a new cam and lifters to put back in, that way you know what you have. The 305 I'm building for my 85 El Camino got a Summit 1102 cam put in it yesterday. This is an "RV" cam, you can loon up the specs if you want, but I wouldn't recommend it for what you're building. Maybe a bit more duration and a wider lobe separation angle.

But, again... fix your ticking issue first! Then worry about everything else! If it is a lifter tick you want to know before you ruin the engine!
 
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57 Handyman

Greasemonkey
Feb 6, 2017
247
63
TYnan, first of all, you need to decide what your long and short term goals are regarding your vehicle. Looking at some of your pictures, your motor has miles on it and definitely could use a rebuild. Of course, nothing is cheap nowadays, so be sure to incorporate your budget/finances and time frames into your decision. Once you do that, you'll have a better idea of how to proceed. From what you've shared, your options are fix troubling issues, such as lifter ticking, timing, etc. and planning/saving for a major rebuild down the road. We all have dreams and desires for our classics but time and money always seem to interject constraints in these visions.

My two-cents...I agree with SSMonteMan as far as fixing the lifter issue. Once that issue is resolved and out of the way, set the timing as suggested by another responder. Then enjoy your ride until you've saved for the rebuild.
 
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CopperNick

Royal Smart Person
Supporting Member
Feb 20, 2018
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Canada
So the head pic sort of tells a tale of its own. First, the gasket isn't a gasket, it looks more like someone didn't have the gasket and tried to go fancy with a generous and sloppy bead of orange RTV. Further down the rail you can see a split in the bead.

That aside, those are stock rockers, sitting on pressed in studs, with no pinning to secure the stud from pulling. The springs and collars ought to be bare metal and only show a layer of good clean oil. The third from the left rocker is about the cleanest of the lot. For the rest, well to me they typify a head that has not seen many oil changes in recent memory. The crud and scunge clinging to those rockers is something like barnacles on a boat hull. They are the build up that happens when an owner just puts gas in the tank and blows off any other major maintenance or service, or only does it when absolutely necessary. You saying this motor came from another donor vehicle would make sense if the donor was some kind of service truck that spent a lot of time idling and only going for short, stop and go excursions like service calls. Company owners come in two general flavors, the ones who understand the importance of keeping their fleet vehicles in good working order and maintain service records and call in schedules for grease/oil/filters, etc, and the ones who buy trucks and cars and just drive them. No service, little maintenance, run them to death and dump them for cheap. Use them for a tax write-off and amortize the value over time.

As for the tick, it was almost a holy writ that first gen small blocks came from the factory with a tick, usually in the lifters. It was not a sign of problems, it was just, how do I put this, a built in idiosyncrasy that seemed chronic. Quick anecdote here, had a cousin with a brand new 70 Nova. Beautiful car, well kept and maintained, but he got rid of it as fast as he could. Why?, NO tick. In and out of the shop ??? number of time, no one could figure out why it didn't have that tick and it didn't run worth a S***. It was a lemon. So.

Much as I hate to put this suggestion on the table, what I see for your motor is a session on the engine stand. There are too many questions about the health and life of this motor to go the band-aid and bandage route. The crud visible in the head shot is a symptom; it points to similar build up and crustification deeper in the mill. Pulling the intake would probably reveal a nasty accumulation of the burnt crispy crunchies clinging to the valley surfaces and drooling all over the lifters and pushrods.

Summarily, throwing a cam at a motor that possesses the potential for needing a rebuild is not a good use of your project budget.
 
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