Alright, so I'm doing a tune up (replacement battery, new oil, etc.) to try to start my car which has been sitting for a few weeks now, and I'm completing the oil change I stick the funnel in the valve cover and notice something very odd. One of my roller rockers has a lot of play. I mean like you could turn it 90 degrees away from where it's supposed to be. I get my dad to check it out and he also noticed that the pushrod seems to be missing. So, we take off the valve cover off the passengers side and sure enough, four of the eight roller rockers have alot of play and the pushrods are off the roller rockers and way too deep. So, we take off the valve cover on the other side and everything is perfect on the drivers side. We then decided to remove the intake manifold to check out the lifters. Well, we remove it and the roller rockers and pushrods on the passengers side heads. All the pushrods seemed to be straight. But when we remove the manifold and guide plate, we find pieces of lifters all over the place. We removed the lifters from the passengers side and sure enough a few of them came out in pieces. They had plenty of oil though.

So, could this be what caused the whole issue with my car? Could the lifters have broken? I mean, I don't think there's anything wrong with the cam because everything on the drivers side seemed perfect. And there was plenty of oil all over the broken lifters too. So, we're planing on putting in the LS7 lifters I have and readjusting all the roller rockers and doing a compression check and seeing if that solves it. We figured that it's worth a try since I already have most of the parts and it will be way cheaper than buying that new long block. And in the end if it doesn't solve it, we will have spent almost no money but just a bit of time.

I have a few questions though. What could have caused those lifters to go like that? Could they just have been old and defective? Or is it possible it was something that happened inside the engine? The weird thing is that is just 4 lifters on the passengers side, and they are like one for each cylinder, and they vary on being for the exhaust and intake valves. Another question is about the LS7 lifters. Is there a certain point you have to set them at when you put them in so they can adjust? Also, where can I find the firing order for the engine and the gap for the valve springs and such. Does anyone have that info on here? My dad is doing the work and he's rebuilt Chevy 350 V8's before, and various other engines. Well, thanks for the help and info.

 

Alright, so I will need a different set of pushrods for the LS7 lifters right? Do you guys think I should just get the pushrods and put everything back together with the LS7 lifters and see if it works. If it does, later I could put in the 226/234 cam, LS7 lifters, Magnum pushrods, Beehive springs, 1.6 Magnum RR's, 36# injectors, and custom pcm tune.

Also, for the LS7 lifters, the cup is about 0.10 inches higher than the LT1 lifters? So, it means I need shorter pushrods? 7.1" vs. the 7.2" stock ones? I'm not changing anything but the lifters and pushrods at the moment, so everything else should be equal right?

Would the 5/16" 7.15" Magnum pushrod available for Comp Cams work? Because I'm not seeing any 7.1" pushrods anywhere.

Or should I first buy the Magnum Master Checking Pushrod Kit (6.125"-11.500") and adjust it until it is right and then measure it to determine which length pushrod I need?

 

You should always check everything and order right parts, but LS7 lifters and Comp pushrods aren't going to do anything for you that stock lifter and pushrods won't. I think you would be better served just getting stock replacements and going from there. I'm parting out my old LE1 engine and have all the stuff you need. 1.6's, stock heads with beehives, stock lifters, and pushrods. Even have my old LE1 cam if you want that too. 224/236 .555/.565 112.

 

If your dad has worked on small block Chevy's, he will know the firing order.... the LT1 is a "Chevy 350" = Gen 2 SBC, with the same firing order.

And for specs, check (surprise) Shoebox:

http://shbox.com/1/engine_specs.jpg

Those are for the stock valve train. If you have an aftermarket cam, you have to check the springs for coil bind, check the pushrod length, etc. But the question I would ask is whether there is an difference in valve train components (pushrod length, spring height) between the left and right sides of your engine. Unless you figure out exactly what caused the problem, there's a good chance your new parts may suffer the same fate.

 

You have provided no information to go on. We assume your engine is stock but then you mentioned guide plates so we know someone modified it. But you didn't tell us how it was modified.

 

I think he said "guide plate" when he was referring to the lifter hold-down spider and guide bars. Always hard to tell.

 

Oh got it.

 

The LS7 lifters are the stock replacement; GM discontinued "LT1" lifters. I just freshened up my valvetrain; I'm running the LS7 lifters, 1.6 CC Pro Magnum RR's with a mild blower cam (218/230/114). I ended up with 7.15" pushrods (stock are 7.2") after checking the were the rollers interfaced with the valve stems.

 

Yes, my engine is completely stock.Previous owner said nothing about head componenets or anything. Though it is possible that maybe they adjusted the rockers and left them too lose or tight or something. But, it only has bolt ons, so all the valve train components should be stock. And I was refering to the lifter hold-down spider and guide bars, sorry. Also, I really don't want to put someone's old lifters on there and risk having them break again. And, I already have all the stuff I mentioned, but think it would be best to get it running again before I put it all in.

Also, I found the firing order. 1-8-4-3-6-5-7-2

And compression should be between 180-240, right?

And I found the info on how to find zero lash and adjust everything.

And I really have no idea what could have caused the lifters to break.

 

Alright, so should I use the 1.5" solid rockers which allow more room for variance in pushrod length and just give them a shot with the LS7 lifters and stock LT1 7.2" pushrods, just for the compression check? If the compression works out alright, then I can put in the 226/234 cam, LS7 lifters, 1.6" Magnum RR's, Beehive Springs, and find the right pushrod length using Comp Cams checker pushrod. And the test outlined in this Car Craft article: http://www.carcraft.com/techarticles...gth/index.html

Maybe I would also replace the Optispark, waterpump, and get an LT4 timing set to complete all the work if the compression checks out. What do you guys think?

 

The rockers are not measured in "inches".... 1.5 is the ratio of the valve lift to the cam lobe lift.

You don't need an LT4 timing set. It has extra, unneeded mass to eliminate some cyclic twist in the LT4 cam.

The important thing about checking compression is not the absolute value of the pressure. It's the variance in pressure from cylinder to cylinder. The actual pressure you measure will depend on a lot of things like the temperature of the engine, the number of times you crank it, the opening of the throttle body, how wet the cylinders are, etc. The key is consistancy in all of those variables.

If your dad is a mechanic, he should know how to do a compression check, and what the results mean. He would probably also want to do a leakdown test to identify problems with rings, valves, etc.

 

Yeah, about the compression check. I've seen it when like seven cylinders are between like 175-210 and then you get that one which is at like 90 and you know you've found the bad one.

Also, I was going through some old shop manuals that my dad had and was looking at the valve adjustment for the Chevy 350 V8's. They had the same firing order as the LT1 and it outlined this procedure for adjusting the valves.

Set the engine in the No.1 firing position and to adjust the following valves:
Intake: 1,2,5,7
Exhaust: 1,3,4,8

Back off the adjusting until lash is felt at the pushrod, then turn the nut in to remove all lash. When lash is removed the pushrod will not rotate. Turn nut in another full turn (though it's been said on here that 1/2 or 3/4 should be enough).

Rotate the crankshaft one full turn to realign the pulley notch and the timing tab zero mark in the No. 6 firing position. Adjust the following valves:
Intake: 3,4,6,8
Exhaust: 2,5,6,7

 

When you say broken lifters on the passenger side, what was it that broke. Was it the plunger and lifter internals or the rollers on the lifters. In any case you need to make sure that none of that garbage is lingering in the pan. Cut open your oil filter and see how much metal made its way through the filter. What did the oil look like when you changed it. Just because the push rods, lifters and rockers were tight on the left side of the engine doesn't mean that a lobe or lobes wasn't wasted on the passenger side.

 

It also outlined the procedure for adjusting the valves with the engine running. Here is what it said for that.

To prevent oil from splashing out of the cylinder head while performing this procedure, the cut the top out of a used rocker arm cover. Tape or file the cut edges to prevent injury.

1. Warm the engine to normal operating temperature.
2. Remove the rocker arm cover and temporarily install a reworked cover.
3. With the engine idling, back off one of rocker arm nut until the rocker arm starts to clatter.
4A. Hydraulic lifters:
a. Tighten the rocker arm until the clatter stops. This will remove all lash (zero lash position).
b.Tighten the nut another 1/4 turn. Wait 10 seconds to let the engine stabilize.
c. Repeat step b two more times. This will tighten the nut an additional 3/4 turn from zero lash position.
d. Repeat steps a-c for each valve.

 

The oil was really black, which was strange since I had changed it recently. Unfortunately, I threw away the oil filter already. I'm pretty sure it was the lifter internals that were out. I saw a spring and a few metal ***** and such.