Hot Rods Trying to set lash the proper way on a SBC 350!

My fingers get oily when I an adjusting preload. I adjust the slack out of the valve train then turn it on quarter turn. I have run mine as loose as 1/8 turn (experiment) but you run the risk of loosing a pushrod unless your rockers have deep pockets.

Adjusting vales solids or hydraulics is about feel as much as it is about numbers.

Unless you got a valve real tight the adjustment is not your problem. Hydraulics are real forgiving. Forgiving enough that you can actually use this chart and get them adjusted in two turns of the crank. Yes it says MOPAR but they have the same firing order. And this actually works believe it or not.



I run the vales on a 355 that we race just rolling the crank until the valve is closed, you are now on the heal of the cam and can adjust the preload. Someone is going to doubt my method, no looking for tension and etc. Last we run it we were turning 7200 in the lights on a cam that redlines ( according to the cam card) @ 6200. I got an idea that my method works well enough.

 

I installed a brand new dizzy last year in a nice '32 Roadster SBC. Same problems as you are having, sooty plugs, back firing on acceleration. Started fine, idled OK. Checked the total advance and it was way up there. Disconnected vacuum advance can & plugged vacuum port. Reset initial timing and found it ran super strong. The owner had 2 choices, leave it that way or re curve the dizzy by playing with advance springs that actually came with dizzy.....................................

 

So i took the previois owners word, that the truck runs fine...we started it up, and it sounded fine. I did not drive it which i should have...short story is i did all the chassis rebuild and did not touch the engine since he had told me the engine is fine. After a complete overhaul of the chasis and ready to put this baby on the road, I did have to replace the fuel pump and rebuild the carb as it had shown bad traces of using ethanol gas (bad white residue). Went to start it at it ran, but would do a popping sound on acceleration. My dad had me pull the distributor, find TDC again and reset timing. We did this for about a month as we felt all the jostling of the distributor and putting the wires on backwards (tach to power and power to tach may have shorted the distributor. Bought a new distributor, popped her in and it fired instantly. Bought new wires and plugs, timed her again and went for a test drive, idled fine but started popping again out the exhaust while accelerating ...so here i am trying to find zero lash, and figuring out what pre load to set...1/4,1/2 or 3/4, so yes she starts, but doesnt run right.

 

Unless you got a burnt valve I'll just about bet you got an ignition problem. I like electronic ignition as much as the next guy but sometimes it screws up. I keep points distributer here to check if the electronic is bad, got to pull the distributer to check it anyway, so just as easy to drop one right back in.

Two ways to check for a burnt valve ( or bent vales too) one is a leak down test. The other that no one does is to use a vacuum gauge. I'll have to look the numbers up for you as I can never remember them give me a minute. I'll be back.

OK slow valve timing or bad valve or intake leak the vacuum will run in the 0-10" range. If you got a burnt valve your vacuum with twitch between good vac (14-25" depending on your cam) and the 10" or below mark.

Another option is a sticking valve. You can check that with a hammer ( light hammer). But you have to loosen the rockers enough to get them out of the way. You tap the stems and watch if one valve returns slower than the rest. Do not larrup it or you'll find a spring flying and never find the keepers.

I would suspect an ignition problem first.

 

Yes...i have those

 

Those are called Polly Locks. I found a whole bag of them the other day when I was looking for something else. LOL

 

Popping noise sporadic upon acceleration or steady? Does popping occur in neutral, revving engine as well as while accelerating under load?

 

The 57 did not pop at idle before messing with the valves, my truck would pop only while accelerating, it now pops in park, while reving engine...but i have not timed it yet after the last valve adjustment which is set right now to 1/2 turn preload. I dont get any backfife through the carb...at all...just popping in the exhaust...wires are all new...plugs too, but they are dark with carbon...all of them!

 

I am going to be headed home from work in an hour, so should i redo my Lash settings...to be positive they are done right ( i will even remove the manifold to watch the lifters open and close if u all think thats a good move) i want an everyday driver...not a race car so should i do 1/4 or 1/2 a turn preload. I do see oil squirt out the poly locks when i untighten them...so i assume they are fine...any tips are very...very...welcomed, damn...any of you live in Maui? I'd pop a few cold ones with y'all and $$$

 

Thank you

 

I run mine @ 1/4 turn year round. But if you are already at half a turn they will should be fine.

First thing I would do before I did anything else is make sure I don't have an ignition problem. Set your timing, first. I am guessing that you threw another HEI in it? Or?????

If your ignition is not the problem then look somewhere else.

If you have been driving it or running it your lifters are pumped up already, taking your intake off won't help you at all.

 

Bullet, in your original post....you said you "when Exhaust Opens, adjust intake and Intake opens, adjust exhaust.
It is supposed to be:
Exhaust Opens = adjust intake
Intake CLOSES = adjust exhaust

 

Ok, understood...yeah, so it is an HEI and it was so hard to find TDC on this truck, that i am afraid to redo the whole point your rotor to #1 cylinder, make sure your not 180 out and it should start...that was a nightmare! But i did get my friends timing light last night, so i was gonna try and set timing today...can i just advance or retard the distributor to set ignition, or do i need to pull the distributor out and redo the TDC process?

 

The dizzy is it a shiny new MSD (or the like) billet?
Do you have 12.6 V going to Dizz?

 

Yes, what you just said, is how i did it...sorry, i made sure that i was on the base of

 

That depends on if you have enough room to turn it or not. Throw a timing light on it and see where you are at.

@brigrat brings up a good point, make sure you got ample electricity going to the distributer. I am not familiar with the MSD units, but any HEI style distributer needs a good 12V power source. Less and you will find it doing odd things.

 

That is the way i set it...you need to be on the base of the cam lobe, not on the lobe itself...i will do it one more time...set it 1/2 preload...call it done and move to ignition timing...good?

 

I do definetly have 12 v going to the dizzy

 

Again what make is the distributor?
JUST SETTING INITIAL TIMING IS NOT ENOUGH.
I would tell you to check your total advance but I would guess you don't have a timing tape on harmonic?
You should still be able to check total advance close enough with a tack and timing lite, should be 34-36 deg. all in around 2K or so.
After you set valves again, read post #32, it's cheap, it's quick and you can rule it in or out, than I will shut up!

 

Haha, ok...i dont want you to shut up, hoping we are on to something...here is the Distributor i bought on Amazon...

Performance Chevy/gm SBC BBC Small Block/big Block 65k coil 7500RPM Hei Distributor 350 454 302 V8 https://www.amazon.com/dp/B072MHVZXJ/ref=cm_sw_r_cp_apa_5idRAbERGS6WW

 

Sounds kinda like my 302 ford did before i figured out the firing order was wrong. idled great, revved good in park, but once I tried to move it, it started popping out the exhaust. So I guess it's already been said - firing order, timing, carb running way lean??, ignition, valves, cam, ....etc, etc.....

 

^^^^^^^^isn't there 2 firing orders for a Ford 302? a hypo firing order and a non hypo?
Rule of thumb backfire threw carb to lean, backfire threw exhaust to rich but I think his problem is elsewhere............................

 

Yeah, my issues are a little deeper i feel...firing order is correct, bought new plugs and wires. Was a bitch to find TDC all over again...i feel like the dizzy is still a bit of a mystery...but my buddy said he timed it right! But i do not have a tach so he mentioned that a tach would be a great idea, so now i am on the valve lash settings...after this i will try to time it...if it still pops...i will be back here...i am gonna pull valve covers and start setting lash

 

Gonna undo all previous settings...here is my motor opened up...

 

Ok...update, i think i found the culprit, Cylinder #1 Exhaust pushrod has been completely levelled off (no roller tip...at all) the intake side is perfect, as well as the rest of the engine...roller rockers and rods are in perfect shape. So assuming the push rod is the issue...can someone explain what is going on if the tip is gone? Should i buy all new hydraulic lifters, new rods, rocker arms...etc. I was gonna set lash, something told me look under each rocker arm...thank you Lord for the headsup, now...what is next fella's

 

Who would have thought except the Lord.......................................
What's next, find the missing part.....................
I would at least buy all new push rods, and one rocker of same ratio..........

 

Hahahaha...i guess its $$$ time to order the missing parts, would you buy new hydraulic lifters and steel rods only? Or rocker arms too...
As for the missing part...i think it has been grinded off over time into metallic dust. I will drop the oil pan and see if there is metal shavings...hopefully the piston and internals are good...thanks brigrat for the suggestions, and everyone else as well. I will keep giving info as i attempt to complete this fix.

 

Looks like the ball off of the end of the pushrod is stuck in the rocker arm. Either way, needs a rocker arm and pushrod.

Sent from my Moto G Play using The H.A.M.B. mobile app

 

Good eye greaybeard! I had to blow the pic up to actually see the end. That's a good thing for OP as there shouldn't be a hole lot of "metallic dust" in oil & bearings...................

 

Stock type pushrods are made by welding the ball end on the tube. It seems the ball is stuck in the rocker. Once you get that out, the rocker may be OK to use. Get a new pushrod and put some assembly lube on the ball so it can wear into the rocker, and some assembly lube on the lifter end. Pretty cheap fix hopefully.

I would suggest setting the lifter preload with it warmed up and running. Get an old valve cover and cut out the top, or better yet cut around three sides and fold the top up to block the oil even better. Loosen until it clicks, slowly close until clicking stops and then add 1/4 to 1/2 turn. That's the best way to ensure each lifter is exactly the same. It also allows you to see if each lifter is oiling up the pushrod.