Hey guys been a while. finally got to the point of starting the rebuilt 350 we swapped into my dad's 76. We got it fired up but there are a few problems. First for some odd reason the water pump pulley is rubbing on the crank pulley. The crank pulley came from a 76 but i think the water pump pulley was not a original vette one so i ordered a new set of correct aluminum pulleys. Thats the noise you hear on the video. second is some of the rockers, i noticed specially on the #5 cylinder the exhaust rocker is barelly moving compared to the others. thats what i tried to show on the video. it's also not getting alot of oil. and oil psi on the stock gauge is low for a brand new engine but we dont know if the gauge may be bad, i plan on hooking up a temporary autometer mech. gauge to be sure. the engine is also smoking through the side pipes but only on the passengers, more at first start up then less after.

the history on this engine is that it was rebuilt about 3-4 years ago and used to run great, was never driven just started (project c3 that never happened) then after a while it lost power and after poping open the valve covers i noticed 2-4 bent pushrods (not on the same cylinder thats not moving now, i believe it was on number 3-4)and loose roller rockers. this was about a year and half ago. i then took the entire engine apart down to the short block. put a new oil pump for safe measure, new pushrods, a full gasket kit, cleaned and inspected everything gave it a fresh coat of paint and threw it all back together. the engine sat on the stand for about a year till we finally installed it on my dads new vette 3 months or so ago. the engine specs are as follows

-.30 over forged trw flat tops 9.7.1 compression ratio
-stock rebuilt heads with Comp Cams valve springs, 1.250 in. outer diameter with damper. .880 in. inside diameter, 389 spring
Rate. 3 angle valve job, milled just for clean up.
-Comp Cams xtreme flat tapped solid cam kit 262/270 duration 462/469 lift, with matching lifters
-Comp Cams hardened chromoly push rods
-Crane aluminum roller rockers 1.5 ratio 3/8 stud
-Edelbrock 600 cfm manual choke polished carb.
-Edelbrock performer RPM intake.
-Summit Racing double roller timing chain
-mallory HEI distributor

anyways here is a video of the engine running. what do you guys think it could be? could a lifter go bad just from sitting? maybe clogged?!

http://www.youtube.com/watch?v=ppXqU0OsfBo

 

Man that's not good. You have at least 4 cylinders that look sick to me. Just off hand I noticed #1, #3, #2 and #8. You either have multiple wiped cam lobes, badly adjusted rockers or bent/wrong length pushrods. I can't believe that thing is even running. Did you change the cam after finding all those bend pushrods last year?

 

I’m with Scott on this. Run the valves first!

If you run the valves and still have this problem you can check the lift (or cam lobe condition) with a dial indicator. If you do adjust the valves and still have this problem there are several techniques for checking the cam lobe lift. On a sad note, if you run the valves and they still look like this, it’s pretty much a given the cam is shot.

Willcox.

 

I would run the valve adjustment again just to verify but it looks like some cam lobes are wiped.

 

Hey guys back to the top on this one. Between all my other projects i haven't given my dads vette any time. so to bring you all up to speed since that video i have fixed the header leaks, just needed new gaskets, got a set of March pulleys so now the crank/water pulley don't hit. Put a new starter since the old one was cranking really hard to start the engine.

so this passed weekend i fired it up again and still same issues of it running super ruff and me not being able to adjust the rockers correctly or so it seems. dad told me to take it to a shop since he's out of the country but a few phone calls later and i get prices ranging from 2-4 grand to possibly swap a cam and go through/tune the engine. yeah sick! this is def. not an option..... anyways few questions

i'm 90% sure the cam can be swapped with the engine still in the car after removing the radiator yes?!

how do i "run the valves" as you guys mentioned, or check to make sure cam lobes are in fact wiped? Heard something about if an engine is sitting too long causes the valve springs to get stiff and when fired again this could cause a wiped lobe? the engine does have comp springs that match the cam in it.

i'm hoping to pull the intake off this weekend and take a look at the lifters, could they have possibly collapsed versus the cam being wiped? the lifters were new with the cam package.

and finally if i do need a cam could i stuff this one in the there with the given engine combo:

http://store.summitracing.com/partde...2&autoview=sku

and should i change the springs and lifters too?

would greatly apreciate your guys help. i really can't believe the prices i got. i guess when you say "vette" people automatically assume you have deep pockets. sucks that i had this engine completly apart and out and didnt see this problem, but i guess now i gotta deal with it.

 

don't everyone jump in all at once now

 

We don't know where to start. You have quite a few problems.

Valve adjustment problems could have caused a lot of your grief.
That would be the first thing to verify. Once you get that right, we can go from there.

Ask more questions if you are uncertain of how to do that.

-Mark.

 

Go through the valves. Make sure you back off the set screw in the top of the poly locks far enough to let you tighten the nut down correctly.

 

Start with #1. Roll the engine by hand until the 1st lifter is on the base circle (no lift what so ever) Get out your feeler gauge & set it to the lash that Comp recommends.

No that cam you mentioned is hyd, your previous specs stated a solid cam, they are not interchangeable. Did you check the cam to crank alignment? Wiped lobes don't bend pushrods, pistons being all the way up with open valves bends pushrods. I suspect a timing issue.

BTW - that engine would be much better off with better heads.

 

Also check for proper pushrod length., push rods dont bend for no reason. You likely have multiple root causes. Also check piston to valve clearances.

Are you running high zinc oil or additives for flat tappet cams?