Technical Changing Cam on a stock SBC 350

Thanks, for now, I'm fine with how the truck performs, even uphill.. its not a huge dog.. I can get up the hill no problem its just not seat of your pants..

Given I drive this only 150 miles per year it doesn't make sense to put any money into it nor even build another engine for cheap. $400 sounds awesome for redoing the 76 350!

After hearing several opinions in response to my original post, I'm thinking I shouldn't change anything unless there is a risk of catastrophic failure or I'm going to get a huge performance improvement for not a lot of money. Based on a few responses to my posts it seems I have low risk of catastrophic failure even if the nylon gears were to fail. I agree with you it doesn't seem to make any sense to change the cam out without being willing to put more money into valve springs/etc. The truth is this truck has way too much rust to make it worthwhile... and ironically thats why I really love this truck because its stress free given I don't have too much money into it (I only paid $2500 for it!) yet all my neighbors constantly tell me how much they love this truck.

Life in San Diego is fast paced and it feels like everyone wants to run you over or its hard to find open space to park so no one slams a door into your nice car which is why restoring this truck is never on my list of things to do and why I don't want to drive it far nor on the highway. I'll have to change my mindset on the 50 ford shoebox as I have 10x money into that thing compared to this truck.... but haven't driven it much since I bought it in March of last year and am afraid I may drive it little because of the same reasons with this truck.. we'll see.

 

I'm going to see if Rock Auto will accept the return and if I won't lose much money on the shipping... if it will incur a reasonable amount of money loss then I may just go for it!

 

I don't work on a lot of SBC stuff, but don't recall ever seeing the damper bolt have a locking tab washer under it. (click on "view attachment" above to see it.

Did they come from the factory with that locking washer?

 

Interesting and on top of that like I said in an earlier post the timing mark is off exactly 10 degrees. I verified this with a piston stop tool.

 

I have seen the star lock washers on the crank bolt from the factory.

 

I agree with @saltflats , I have a 350 horse 350 short block that has the washer on it.

 

I've been reading along on the other threads.

Questions I'd be asking myself if I were you include;

1. How much as a decent crate motor and suitable ancils
2. How much is a decent used, tested, 350 complete.
3. What is the rebuild cost of the smog motor to include some upgrades
4. If the smog motor grenades would it be at all viable to rebuild it.

Armed with that info I'd be thinking I'd be doing as little as possible to the existing engine and saving up in the hope that the explosion is far enough away that a decent sum may amass. Possibly dyno it ( not expensive) as it stands to find out how little power there is.

Your cam timing is out. Your timing mark is unclear, we'll it is to me (but now your suggesting it's 10 degrees out, so the dampener was manufactured wrong?). There's no certainty in my mind that the ignition timing isn't self variable by virtue of the slop in the timing chain. None of this will be helping power.

I can understand the idea of swapping the cam whilst changing the cam gear, but doing so for making more noise to annoy your neighbour when perceived lack of power on hills is the underlying issue, c'mon! We don't know the spec of the engine but believe it to be a smog motor. The components in an engine are, or at least should be, a collection that work together. It's not mix and match. The compression ratio is unknown but must be presumed to be low. A performance cam isn't going to work well with that. So do you swap the pistons too while swapping the cam? Heck, the heads too for that matter! Or wait to do that till after the big bang ( from the pending timing gear failure)?

Your a busy, young guy with limited funds, your analytical mind is all over the place, and for what, a truck that sees 150 miles per year.

But don't be put off or too deterred by this ageing, frustrated fart.

Chris

 

I’d still change it out. It’s a PIA to do, not a 1 hour job for sure.

 

First off, I have not read the entire thread or the other threads on this specific truck/topic but, something crossed my mind regarding your apparently having issues climbing hills. If the vehicle has an auto trans (I have no idea if it does), is it possible the trans isn't automatically kicking down a gear while making the climb or is the operator not dropping a gear manually if it's a standard trans?

Just a thought.

 

Circa 1975, we had a parts store (Mars Auto Store, Bay Shore NY...which is still around..) that sold speed equipment. We always got the jobber discount. He was a Wolverine Cams distributor. We put that shit on everything.

No matter how old an engine was, they always benefited from a new "hot" cam, timing gears and lifters. Most of them lasted a while and took a beating. Fast forward to today and having more loot to spend, I'll go the whole 9 yards and tear one down before sinking too much into it.

 

Thanks! Money isn’t the issue, me being cheap is.. I have plenty of cash and could unload this truck and get a fully restored one with not a spec of rust and a good engine but then I won’t drive it… I find my region is very stressful for having nice cars and not feeling like someone will run over you or shove a shopping cart or their door into yours. I don’t want to throw a whole lot of money at this truck for a rebuild or other used motor given the rust it has..

If $171 USD prolongs the possibility of a grenade with the timing chain gears failing… that’s worth it for me. I might remove the timing cover and find the previous person already changed with all metal at which point I wish I had not touched it but I already bought the timing set and it would cost me $25 plus return shipping so like $50 total in loss so at this point it’s almost dead certain I’ll be replacing the timing set. I won’t bother with the cam. The benefit is I’ll fix the slack existing in the chain and some leaks coming from the timing cover and oil pan.

 

Im going for it… I successfully did the two timing chains and guides on my Nissan xterra in 2021 and that was like pulling teeth from a horse.. I suspect this is an easier job.

I’d lose maybe $50 returning the parts to rock auto…. I’m planning for 2- 3 day job (given I get distracted a lot and the surfing is good this time of year) and will start on Saturday

 

thanks I have a th350 and kickdown cable is connected. I’ll have to double check its operation. My truck climbs the hill I live on ok but my pedal was near the floor doing so and I wasn’t going super fast (about 38 mph) so it made me think I don’t have much power however I later discovered the person who rigged up the pedal linkage had it max out at maybe 60 percent. I fixed that and will try driving uphill again.

 

Do you have the tools to pull the damper off and reinstall it?

 

O’Reilly auto does… I was there yesterday and saw it in their loaner tool section.. at least they have the puller … I’m not sure what is needed for install.

 

You can use a 2x4 and a BFH to install it, but they should also have the installation tool that threads into the hole in the end of the crank, which is there on all the 350 engines (but not most of the earlier ones)

When you pull the damper off, be sure to note that the threads in the damper that the puller bolts fit into are fine thread.

 

Thanks for all the advice! Will do! I'll report back once I get underway with the timing set.

 

When you get around to changing the timing chain and sprockets I wonder if you might do me a favor. With the engine warmed up, pull the plugs and run another compression test. Compare your readings with the results you posted earlier.

Humor me. By advancing the cam timing by maybe 8 degrees I suspect that you'll likely see at least a slight increase in compression readings across the board.

 

Sure! I could do that, was a little bit of a pain and burned my arm a slight bit when I was doing the first plug but by the time I got to the last one it was cooled down enough.

I bought this timing chain:

https://www.summitracing.com/parts/clo-9-1100

Do I need to degree it a certain amount or should I check total timing advance now before I start taking things apart to determine that?

 

I'd set it to Zero and not worry about degreeing it.

Of course, if you want to get a dial indicator and a degree wheel, etc, you could have fun degreeing it.

 

Yup . . . What Jim said!

 

When installing a double chain in place of a single on a SBC, check to make sure the new chain isn't rubbing on the block, behind the cam gear. I have had to slightly grind the block for clearance when going from single to double on a SBC.

 

Will do thanks!

 

I’m curious, if you eyeball it, can you get a straight shot at the balancer and a block of wood? I suspect even with the grill and radiator out, you might have an issue there.
To be safe, I’d get an installer lined up for when needed.

 

Thanks, looks like Oreilly loans out the installer as well. I'll make sure I have that on hand.

 

they sell it to you, and then buy it back. I have one of the Oreilly ones that I bought to work on Mike's car on drag week in 2013, and never returned even though I have an older Mac tool that still works fine.

 

Haha yep, they ask for a CC, give you the receipt and refund your money when you return it.

 

X2. I got lucky on the cloyes on mine but I've seen many rub with the exact same set I have. I actually spent a half rechecking clearance because I couldn't believe it cleared lol

 

This just in from the racing trivia dept. Grumpy ran nylon timing sets in his 331 pro stock motors. How many rounds I don't remember, have to look it up, but the reason being he noticed it absorbed abnormalities in the valvetrain better. That and 2.29 will get you an x-large coffee at the Speedway gas station tomorrow on your way to work...

 

I remember reading that.