xdc351

Hi guys,

Finally fired up the 'ol clevo again today and noticed a rattling strange noise that I don't recall hearing in the past.

At about 3000RPM is very noticeable and from the car it sounded like it was on the passenger side. So after I got it home I pulled the rocker covers and started checking clearances.

Driver side, fine zero lash all the way (hyd cam).... but on the passenger side no5 ex I have .015 lash and cannot get it down to zero lash.... I can also push the rocker backwards by hand a good .050 with ease. Something i've not seen before.

I'll admit troubleshooting isn't my strongest point! But if anyone can advise me what going on i'd appreciate it.

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Just like a Tsunami.

brenx

I've seen too many of these late model blocks chewing lifters/camshafts lately when using high lift cams. I'd be pulling the manifold and checking the lifter. Especially if the lifter is gone better to be safe than sorry. Left alone metal would go through the block/oil galleries (not good). How old was the camshaft? How many k's did it do?

This doesn't seem to be an issue with the early blocks? Wonder why? I gather the casts were in better condition then?

Brenden

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XB Fairmont (street car) 11.07@123.02mph.

ESP

A bad pushrod or bent rocker arm can cause those symptoms.
What does it idle like.

On a side note...........the OPTIMA fires the beast up on a poofteenth of an engine turn..........it idles better and the Thermos sound like they're spinning faster. Getting the bugger secured to the battery tray was a bigger trial than expected !!!!!!!!

Hope the rattle doesn't turn out to be anything too nasty.

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XE ESP The last of the CLEVO's
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xdclevo

I had a wiped cam (all 16 lobes) recently but it didnt wear the base circle, only the nose of all the lobes, so wasn't noisy. If you want to check some lifters, you should be able to take out 4 lifters quite easy with just the rocker covers off. I did it this way to check that last rooted cam i had, and used the $10 or so supercheap telescopic magnet to remove.

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10.70 @ 125.00 on the black fun top
408 Cube Cleveland.

Work Horse

Dam xdclevo bad luck! That must have made a mess.

xdc351 If you have not driven the car for a while the lifter may have bled down and may be taking it's time to pump up.
As ESP said check for bent push rod or rocker. What rocker set up are you using? If you have a modified hydro cam are you using shims to obtain correct lash.
I'm using the shims and broke one once. I also had to readjust mine several times.

xdc351

The rockers should be OK. RR's and chro-moly pushrods should take the heat ok!

After a 25 minute cruise I would have expected the rocker to pump up. If it hasn't then its time for them to go.

At this stage i'm looking at tossing the cam and lifters and getting a cam better suited to the 425 impco.

__________________
Just like a Tsunami.

Work Horse

Agree you would not bend a RR, but still worth checking the push rod

Agreed

What's in it now?

xdc351

Thats just it, i've NFI!

The cam came with the engine and he never gave me any specs. I know its too big for the carb (dyno tuning).

I'll be checking all the pushrods when they come out.

__________________
Just like a Tsunami.

Work Horse

Arr that does make life a little difficult!

xdclevo

Yeah it was very messy. New everthing, including block, 1 piston and also a crank grind.

Just with the zero lash thing on the loose ones, when trying to preload, is the spring in the lifter pushing the plunger up against the retaining clip before the pushrod is preloaded onto it, or is it collapsed? Also the roller should be able be adjusted a long way. Do you have 7/16 screw in studs ect?

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10.70 @ 125.00 on the black fun top
408 Cube Cleveland.