Technical Changing Cam on a stock SBC 350

oh yeah, I forgot you're not pulling the intake, ignore the stuff I mentioned about the distributor. been a long day.

Get the dots to line up, next to each other (6:00 on the cam, 12:00 on the crank), and then replace the timing set, with the dots at 6 and 12 as I mentioned. Ignore the position of the pistons when you are aligning the dots, only pay attention to the dots, have them next to each other, and in line.

 

If you leave the dizzy in........ It is totally "in phase" with the cam timing.
So it doesn't matter if the dots are at 6 o'clock or 12 o'clock. All that means is the crank has turned 360°

Don't pull the dizzy, just set your timing later with a timing light.

 

I dont know where the timing dot on the crank is when #1 is at tdc. If its at the top then great, if not forget the distributor and tdc and get the dot in the right place, and then the cam to match, as Squirrel has already said. Don't complicate it. Get the cam timing all wrong and it'll never run and probably bend valves trying. Worry about the distributor later; it might not be an issue.

Chris

 

I pulled the chain and cam sprocket off but I can put the cam sprocket back on and get them to 6 and 12 o’clock … is the point of doing this because it minimizes the risk of being off a tooth by eyeballing both at 12 o’clock?

 

hard to see in the photo but at tdc #1 compression stroke the top cam is at 12 oclock. Bottom also at 12 oclock

 

Cut the corners off the rails on the back of the timing cover .
Clean the oil off everything.
Shove the timing cover back in down hard and tip in place with a lot of Permitex Right stuff in the corners.

You get that pan loose and can't get it out your opening a big can of worms .

If the engine has low power I'd be looking to see if the cam is worn out on this high mileage tired low compression engine.

Unless your planning on climbing these highway hills at 5000 RPM Changing exhaust manifolds to headers , cam timing changes and stuff is going to do very little with a 2BBL engine with the cylinder pressures you noted .

IF and this is a big IF the bottom end is not tired and is worth add ons you need some heads that get the existing pistons to yield about 10-1 compression, a RV type cam and a good dual plane intake like a edelbrock performer and a 600 to 650 CFM 4bbl .
Your doing a lot of work for not much gain
You need low-end torque in that heavy truck . Hot Rod stuff is not going to gain a lot unless your going to spin the engine at higher RPM and then that motor is not long for this world likely.

 

Turn the crank 360 and they should line up if they're correct.

Chris

 

Do you have a service manual you can refer to ?

On just a timing change swap you could have lined up the old marks . Pulled your old sprockets off leaving everthing in place and pit the new stuff on

 

I’ll keep all of those points in mind for the future. It looks like I have room to drop the pan a bit at least a few inches maybe more but not sure if it’s easy to work a 1 piece fel pro pan gasket in there. I already bought it from rock auto. I’d have to remove the starter though… hmmmm

 

You going to play hell scrapping the gasket off the block and getting all the crap out of the pan that's going to get in it with only a few inches to work with.
That one piece gasket needs to go under the oil pump pickup and best not to get it full of oil and crap doing it .
Disturbing any gunk in that pan and not getting it clean is going to suck up any crap in the pump and cause issues .
Pulling the starter is the easy part in this.
Here is how the timing marks go .
Need to be on top dead center

 

If you trim the cover about like this use a newcorrect original type rubber like the old one that's in your timing now with the edges trimmed off you can get the cover back on with the pan in place.
Lot of guys loosen about the first 6 pan bolts to let the pan flex down.
You run the risk of tearing the gasket however.
Leave the new timing cover/ damper seal out untill the cover is in place.
You only silicone the corners .

Not a lot to loose trying it .

I have done it about a dozen times doing cam changes

 

Do these photos make it easier to tell if that pan can come out ? I am worried about loosening it up to just find out I can’t get it out without lifting the motor off the mounts which I can’t do.

the one piece felpro gasket was $24.99 and maybe can be shipped back to rock auto if I don’t use it.

 

that looks pretty easy to remove...well, not nearly as bad as some are.

looks like the end of the pan gasket is gone, so you'll probably have to pull the pan.

So much fun. I would have left it all alone, but then I'm lazy

 

thanks I’ll try to pull that pan off then!

 

I did the pan on my 1970 C-10, years ago, block and floor jack under pan, little pressure so both long bolt's come out of motor mounts, raise a little bit so 2x4 sections went between mounts, lower jack, pan came right out. Watch firewall to dist. clearance.

 

The 63-66 trucks have the engine sitting further back in the frame, compared to the 67-72 trucks. So it should be easier with the older ones.

 

yep and as a result I had to suffer and rest my stomach in between the radiator and engine to reach far back when I did the #7 and #6 valve seals.. I hope I paid it forward and the oil pan comes out easy.

 

Looks like it might come off if not since you already disturbed the gasket and have the bolts loose might as well try . might have to raise the engine up if not .
Id advise cleaning the damn engine off before you take it apart with a few cans of brake clean maybe a wire brush . If have taken it to a car wash or had it pressure washed before starting on the cover.

If you need to rotate the crank have the timing chain on so you don't hit valves and such.

I assume you drained the oil already ?

 

Yeap .

 

Make sure the pan gasket is for the correct dip stick orientation as well LH or RH

 

Will drain the oil in the morning and resume with the pan and rest of timing chain work.

 

It makes sense to have the chain on when turning the crank. I've read in some other places to set the crank at 12 oclock and then take the chain off and turn the camshaft sprocket by hand 180 to get it to 6 oclock. Would that be bad practice and lead to bent valves or is it likely there's less leverage with the camshaft turning vs crankshaft and the lifters absorb some if the valves contact the pistons? Not sure what valve interference takes place turning the cam 180 clockwise with #1 and #6 pistons stationary at TDC.. It seems easier to turn the camshaft and crank with chain on 360 to get that position.

 

leave the chain on if you need to turn the engine.

Also keep in mind that the cam can be at either 12 or 6 oclock when you align the marks...it's just easier to see them when the dot is close to the other one, at 6

 

yep, that's what I thought at the beginning and why they say to go "dot to dot" so there is less chance of being off one tooth by eyeballing both 12 to 12.

I've seen even in the comp cams instructions for instance (was just curious) where they say to install the crankshaft sprocket at 12 o clock, then install the camshaft sprocket and rotate it so its in the correct orientation, then take it off, put the chain on it and the crankshaft sprocket and then install it and bolt it up and torque it down.

I imagine that would lead to bent valves... or at least maybe ok to turn just the camshaft sprocket without the chain on..

 

This method work's great when there is no valvetrain to deal with, like with a cam swap. But the way you're doing it, with the intake on and distributor still in and the valve's still adjusted, the chain need's to be on so the valvetrain moves the way it's supposed to, most people can't do that by hand. But if you can, you're one Bad Ass Mofo!!! LOL! If you're not too far along already, I'd suggest putting the chain back on and line the mark's up according to the manual, just to be on the safe side. Just for future reference, when cyl. #6 is at TDC is when you're dot to dot on the gear's.

 

Instead of dropping the pan you can remove the front 4 or 5 bolts and lessen a couple more, then take a couple flat blade screw drivers and tap in from the side kinda at a angle . The pan is now down a little at the front. Use some RTV and put it in the edge of the pan rails as best you can. To install the cover put it in at a angle with the bottom going in first. Use a couple small phillips screwdrivers to give you some leverage , put them through the cover into the block and push down and pop the cover right onto the dowel pins. Pull your flat bladed screwdrivers out tighten it all up and your down. There is probably no worse job the installing a oil pan on the car. Especially if your working on your back. I haven't done hundreds but I have done my share in another life.

 

I read through this whole thing this morning. Chalk this up as a learning experience, you got a good education.
When its all said and done and its back on the road, you will find you wasted your time and money, I seriously doubt you will feel one bit of difference in the way it runs or feels. Good Luck

 

already ahead of you.. the minute I took the timing cover off I thought I should have listened to squirrel and not do anything to the engine but it was too late I already had ordered the parts from rock auto and $50 to return… Chevy pope put a good scare in me regarding the nylon cam gears in another one of my threads so I ordered the timing set, gaskets and harmonic balancer… at this point learning experience more than anything

only good thing is it leaked a bit from the timing cover and oil pan before which was always annoying.. at least there’s a chance I can improve that.

 

The thing about the plastic gears is that they age whether you drive it or not. Sitting a lot may actually be as bad as driving them. When they do fail, there is a lot of hassle involved and possibly some $$$ to get the truck back home. Its better to do the preventative maintenance before hand when its at your convenience and you can take as long as you like. When a timing gear fails, you get lots of stuff that may fall into the oil pan. Depending on the engine type, there is also the possibility of a valve to piston collision. I think it was maybe in the 80s when cars were running belts on the cam gears that there were a lot of bent valves. Subsequently many manufacturers began designing engines that allowed a fully extended valve NOT to hit the piston when the belts failed. Its a crapshoot to say that your engine will/will not suffer any damage.

The issue seems to be your hesitancy to tackle the problem and just cross your fingers. Why not consider it as an opportunity to learn something and improve your skills at the same time. No sense putting that time and money into the beautiful car that you are afraid to drive.............put it in the truck and then drive it more. I met a guy at the SRN who drove down from Canada in a really nice 32 Ford. He told me he had a beautiful 32 Ford with a high dollar paint job........but he couldn't enjoy driving it for fear of getting nicks and scratches in the paint. So he sold it. Then he built another one (That I thought was really nice) with a cheaper paint job and less frills and he drives it everywhere.

Met another guy at the SRN named Mert. Had a primered coupe with no hood or fenders. Drove it anywhere and everywhere no matter the weather. Said he put a plastic bag over the distributor when it rains. Drove 800 miles to get to the Nats.

I'd reccomend working torward making the truck a "driver" rather than a "sitter" and just enjoying the he** out of it.
Quit worrying and just fix the potential problem before it happens. Then Enjoy..........

 

good points… in San Diego it feels people run your ass over if you’re not doing 80 mph even with 70 mph speed limits… it’s very stressful to me… I used to enjoy driving along the 101 to get some more miles in but it’s so crowded and full of traffic now. San Diego post Covid has gotten so much more crowded (lots of San Francisco and LA transplants who can work remote) and changed my perspective and willingness to drive far anywhere be it my daily (xterra) or the truck or shoebox ford.. eventually I may sell my house and leave but we’ll see.. for now I’m surfing as much as I can when not working (the primary reason I moved here 17 years ago) while I still can. I don’t mind still having the truck and shoebox ford for short drives though.