454 Worn Cam Diagnosis, what did I miss?

[fatguyzinc]

why would you get this far and NOT change the cam & lifters too?
whats a new summit cam, $99? even if the cam & lifters look/seems fine,
CHANGE IT.

you'll be kicking yourself in the you-know-what if you dont and you
have to go back in and do it afterwards.........

[squirrel]

If you are sure they're hydraulic lifters, then give them all a half turn after setting them to zero lash. I do one cylinder at a time when adjusting them, starting with 1 and going through the firing order, turn the crankshaft a quarter turn each time I before I move to the next cylinder. This works fine for adjusting the valves with mild hydraulic cams.

[anotheridiot]

If you are really not sure of the lash of the valves, tighten the rockers BEFORE you put the intake on. That way you can watch the plunger move when you pass zero lash. It gives you more room to turn the pushrod as well.

[andy30thz]

Thanks guys! We're starting reassembly tonight.
The plans for this thing are;
1) Get it running correctly
2) Mild shift kit & restore the kickdown function (TH400)
3) Mild 2.5" exhaust (already has long tubes)
4) Mild drop
5) Fix all the little things that are annoying or broken
6) Clean and polish everything as best we can
7) DRIVE IT!

[andy30thz]

solid lifters?

You were RIGHT! We had missed the part number on the lifter...99250. Crane solid lifters. I totally missed it. Too busy trying to do too much. We definitely need to slow down and not rush. This build has things that don't seem traditional.

Also...more to the story. When my buddy dug this truck out...it was PACKED in a shed with three other vehicles and had shelves built infront of them... They were definitely left for long term storage.

When I say the rockers are "loose", I don't mean loose enough to clack, I mean loose enough to wobble around in your hand when the lifter is on the base circle!! REALLY loose!
So loose I don't think any oil was getting pumped up the push rods to the rockers...(fortunately it wasn't run very much and no visible wear is detected on rockers or valve stems)

The only thing we can come up with is the previous owner backed off all the rockers for llong storage and he knew how many turns it would take to put it back, but he unfortunately passed away and never had the chance.

[squirrel]

if they are solid lifters, he would have adjusted the valve before starting it. But he didn't leave a note to remind the heirs, I guess.

The thing is, all your symptoms pointed to them being solid lifters...

[andy30thz]

Yep, you were absolutely right!
I made some incorrect assumptions such as "why would anyone use solid lifters on a truck with 2" exhaust, swapped in 8 lug axles, used to haul a boat, camper & stock cars"
But after working in his shop...I get them impression he built everything with what he had on hand.

I need to do more research on how to set lash with solid lifters. (I've read the basic concept, engine warm, feeler gauges between the rocker & valve tip)

I'm assuming solid lifters can be used on a cam that was ground for hydraulic lifters? Most solid lifter cams are pretty big! I don't think this cam is...? But I definitely shouldn't assume anything at this point.

Oh well, we had fun working in the garage, learned a lot and cleaned & fixed a bunch of small neglected things while we were at it.

[cstmwgn]

I lash my valves cold - stone cold. I use the EOIC method
with the exhaust just starting to open - adjust the intake
with the intake almost closed - adjust the exhaust

The question is how much lash - with no knowledge of the cam it most likely will be somewhere in the mid 20s - .024 - .026.

[squirrel]

solid lifters go on solid lifter cams, hydraulic lifters go on hydraulic lifter cams. The ramps are shaped differently.

[squirrel]

also, you can measure the lobe lift of the cam to give you an idea how big it is. To get valve lift, multiply lobe lift by 1.72 (which is the rocker arm ratio).

[squirrel]

this is a relatively small cam....

https://www.summitracing.com/parts/cca-11-674-4/overview/make/chevrolet

and it's a solid lifter cam.

[anotheridiot]

Every time I get to thinking I understand camshafts a little more, a thread like this comes up and makes me question EVERYTHING again.

[PHWOARchild]

We always ran solid cams (Chet Herbert !!) in our stock cars, the L88 cam was a good cheater cam when the big block was in the car. Totally different animal from a hydraulic cam.

[andy30thz]

Dang! Forgot to update this!
Yep, it was a soild cam and we made a lot of newbie mistakes but after a bunch of research and reading Harold Brookshire's posts on chevelles.com...we ended up running the Lunati Voodoo 60201 hydraulic cam.

http://www.lunatipower.com/Product.aspx?id=2149&gid=287

From everything we can see (looked in cylinders with borescope and pistons look like stock rebuilders) this engine is mostly stock parts and will never spin over 5000rpm.

Harold always recommended this cam for that type of combination and a bunch of people ran it and were amazed that it truely pulled from idle to 5500, just like the description says. (with the correct parts and tuning of course)


The break in went fine and we're back to fixing EVERYthing else this truck needs. Thanks to everyone for your help.

[oletrux4evr]

Does the exhaust flow match the engine speed? If not, probably an outside chance the catalytic converter is clogged.

EDIT: Duh. I think I misread the post above..........I thought the cam swap went well, not that the problem was solved. Silly me.