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Manta Gte


dw10ant
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I have a Manta GTE fitted with the 20E engine on the ramp.

This vehicle came in as a non starter after the owner had had the cylinder head off to replace the valve stem seals.

Long story short - the cam timing was out by one tooth, corrected and engine turned over - no compression on any cylinder.

Rechecked everything. Suck, squeeze, bang, blow all OK.

Cylinder leak test carried out - air escaping past valves.

Unable to determine the reason and suspected bent valves.

Cylinder head lifted off when number 4 cylinder positioned on compression stroke.

Valves on number 4 cylinder not seated but being held slightly open.

Slackened the rocker retaining nut and the valves lifted and seated.

Thinking that the hydraulic tappets had 'jacked up' I removed them and slowly squeezed the oil out of them in the vice until the top of the lifter was acting on the internal spring with no oil pressure.

Refitted the lifters and screwed down the rocker nut which caused the valves to start lifting again before the nut was completely seated.

A closer look at the set up and a bit of thought - if the rocker retaining nut is tightened fully the rocker will lock down against the cylinder head. It would seem therefore that the retaining nut should not be fully tightened but there must be some clearance allowed on initial set up to allow the valves to seat, with the free movement then being taken up when the hydraulic lifter is pressurised.

If I am correct, what is the approved method of fitting the hydraulic lifters and rockers.

A swift reply would be greatly appreciated - need to get the car off the ramp and away.

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basically if all valves are ok & the tappets are all functioning correctly (ie not seized up /etc )then sitting them up is realy simple. working on each cylinder at a time .turn engine to open one valve & adjust the other until the tappet is JUST BEGGINING to compress.turn down ONE FULL TURN ONLY from this & youre done.

now turn engine until this valve is open & adjust other one. etc etc ,untill all 8 valves are done. .all will now adjust itself up when running (will sound rattly at first until they all fill up with oil. )

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basically if all valves are ok & the tappets are all functioning correctly (ie not seized up /etc )then sitting them up is realy simple. working on each cylinder at a time .turn engine to open one valve & adjust the other until the tappet is JUST BEGGINING to compress.turn down ONE FULL TURN ONLY from this & youre done.

now turn engine until this valve is open & adjust other one. etc etc ,untill all 8 valves are done. .all will now adjust itself up when running (will sound rattly at first until they all fill up with oil. )

Exceptional response, many thanks. Just about to leave the garage and go home so I will set it up tomorrow.

I expected it to be something like this and looked at the operation by turning down until a 35 thou feeler gauge just slipped in and out.

I didn't just want to go on guesswork but couldn't find the correct setting up procedure. I have shelves full of old Haynes Manuals but not one covering this engine and I couldn't find anything on the net.

Anything I can do to repay just post or e-mail me.

Dave Tennant www.bitzmotorsport.com

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