My 67

[Keefyboy10]

Hi everyone. I'm new here. I've just brought my first Pontiac. It's a 1967 firebird with a 326 engine and auto box. I've got a problem with the engine, and was wondering if anyone could give any advise please I shall start from the beginning, but may get a bit long winded lol. I was told all the info from the bloke I brought it off ( he owned it for the last 9 years)

The car was being used(few years ago) and the engine was running fine. Then the oil light came on and big ends knocking. The engine was pulled out and was told that the oil and filter hadn't been changed for about 10 years and that the oil ways were blocked and lack of oil on top of the engine. so this is what caused the problem. Had the crankshaft regrind , new oil pump and piston rings fitted. the engine was put back in.

The bottom of the engine is now good,but now there is a rattle on the top end. Have got oil coming up into the pushrods(heads) . Have taken off the rocker arms, pivot balls and pushrods. The pushrods look fine. But on the pivot balls, in the centre of the hole, there are remains of a nylon insert. These press fit into the top half of the pivot balls. They look like they take the play out of the rocker stud? You can see they all had them fitted, but they have all worn out (in pieces)

So I've phoned 2 company's but they have both said that they can supply the rocker arms with a set of pivot balls, but they don't come with the inserts, and they don't no what I'm on about lol.

I thought I'd try and adjust the rocker arms first,before taking the heads off and checking the cam shaft and lifters. I've also forgot to put the engine spec lol. It's a original 326. The heads reconditioned including new springs and rockers. Cam crane hmm 272/284 . 454 duration lift. Roads variable valve timing lifters.

Is there anyone so kind to try and point me in the right direction.

Kind regards
Keith

[bhm1712]

Hi Keith i have moved your Topic to the Tech help section where it will get more responses.

[bhm1712]

Do you know what brand the rocker arms are?

[Keefyboy10]

Ive cheaked the paper work ive got and it doesn't state any brand name, so I assume they are standard?

[bhm1712]

Im assuming the lifters are Rhodes variable duration lifters and not variable valve timing lifters As variable valve timing is a totally different kettle of fish and wouldn't work with the standard rockers etc. the variable duration lifters are noisy much like a solid lifter.

As for the rockers the standard bottle neck rockers are non adjustable and usually only consist of the rocker arm and pivot ball and no insert. Can you take a photo of the rocker area please?

[Caz]

Hi Keith
We are not far from you. Felsted. If you ever fancy a chat and a coffee

[Keefyboy10]

hi ian,thanks for the reply,on the spec sheet it states that they are rhoads variable valve timing lifters.they are adjustable,will post some pics of the rocker arms,ect ,over the weekend,

[Keefyboy10]

Hi caz,sounds good to me. Do you go to many shows?

[Keefyboy10]

hi ian. here are some pics i have taken. if you would like to see anymore,just let me know

[Keefyboy10]

and these ones

[bhm1712]

sorry to be a pain but do you have any pictures of whats left of the nylon inserts?

Those rockers look identical to mine - standard bottle neck stamped rockers, and they dont usually have any nylon inserts.

[jonbullnose]

yeah as ian says they are std from factory rockers im interested to see the inserts as well never seen them before do the all the rockers have the oil hole to allow the oil to flow up the pushrod and over the rocker ? also does these inserts have the hole in them as well as i have seen it before where the holes in the rockers were missing and it was making a nasty noise as no oil was getting to the ball/rocker stud area it looks like those lifters are a half way house between normal hydrylic lifter and a solid, the lifters are adjustable from 10-30 thou by the looks of it i would say the lifters are wrong for those rockers or vise versa you need adjustable rockers really with roller tips if poss as it will be putting the rocker arm ware pad in a place it is not ment to be and putting quite a lot of side load on to the valves and guides , if its like a solid lifter then it will be very noisy at idle like a sewing machine, these lifters are normally used to make a radical cam usable in street driving there often used as a band aid where some one has a high lift cam but does not want to spend the money to build the valve train right .
you will need to be carfull if you change anything in the valve train that the rockers do not come into contact with the top of the valve guides

jon

[bhm1712]

Yes agreeing with Jon here,

Usually aftermarket non OEM style lifters require aftermarket rockers as well. The factory stamped rockers are non adjustable and are purely torqued down to spec and left. If the valve train wears and the clearance becomes too much it usually dictates new components. Hydraulic lifters negate the need for adjusting valve clearances which is why the factory rockers are fixed and not adjustable. If the new rhodes lifters do not have the same spec as factory lifters then this will cause problems.

[bhm1712]

I'm beginning to wonder if this nylon insert was some form of bodge to create a bit of an adjustment on the rockers to compensate for the aftermarket lifters? So that if the rockers where not fully torqued down then the nylon would take up the slack and quieten down any tapping noises.

[jonbullnose]

yeah im thinking the same ian the rockers are normally tightened to 20ftlbs off the top of my head were these tight or left loose ?

[Keefyboy10]

Inside of the pivot ball, half way down from the top ( see pic) has a recess , and the nylon insert finished just upto this

[Keefyboy10]

The pivot ball was inside the the rocker arm, then the locking nut,then the long nut thing followed by the grub screw (the long nut thing has an internal thred for the grub screw). Hi jon. The rockers were tight before I took them off. The rocker arms have got holes in for the oil ways,but as I used my phone to take the pics, hasn't come out so you can see it. I can put some better pics up once I have got my camera sorted

[bhm1712]

Those rocker nuts are incorrect for that style of rocker arm.

They should have simple "standard" type nuts just torqued down 20-25 ft/pound. Those nuts are for an adjustable style rocker!

[Keefyboy10]

Hi. Have you got any ideas on how I can get this problem sorted out?. I'm not sure what to do at this stage.was thinking about taking the heads off and checking the cam shaft,lobes and the hydraulic lifters? Any help would be much appreciated. And thanks for all the help so far guys

[bhm1712]

you dont need to remove the heads to check the cam lobes and lifters.

Remove the carb and intake manifold.

Undo the 2 bolts which hold the valley pan down, prize up the valley pan as the gasket will be securely stuck by now im betting.

Then you have easy access to the cam lobes and lifters, Just take out the pushrods to remove the lifters.

[bhm1712]

if the cam checks out ok, i would be inclined to buy a new set of lifters, and proper adjustable rockers to match the cam as specified by crane.

http://www.flickriver.com/photos/kneebeau/3498304676/

here is a photo of the Pontiac motor with the valley pan removed for cam and lifter inspection/work. This is a 400 motor, but 326-455 is the same.

[Keefyboy10]

Thanks a lot for the info Ian. Will let u know how I get on. Much appreciated.

[bhm1712]

Just be aware, cleanliness is very important when taking off the valley pan. Below that the cam shaft is exposed, and directly below that there are the crank main and rod bearings. Nothing is there to stop any crap dropping down onto them. The lifter valley can be a settling ground for sludge and metal filings from normal engine wear over the years, and if disturbed it can mean an engine rebuild in a few miles! ive heard of people doing a simple lifter swap and then a few days later having the engine wreck itself due to CENSORED dropping down. get plenty of shop rags and immediately cover the exposed cam shaft and webbing and clean out any gunge before doing anything else.