Trumpet Base Removal and Rocker gear checks
Discussion
Hi folks,
Just in the process of a few top end jobs, main aim is to replace the fuel presure regulator with a 3 bar unit and pull the fuel injectors for testing. While I'm at it, I'm also planning to install an sc-power insulator gasket and replace the rocker cover gaskets.
Currently stuck trying to remove the trumpet base. I've removed the six bolts, and tried a reasonable amount of force, but it seems to be stuck solid. Any secret to removing it? I can't really see any easy way to get any leverage from below.
Also removed the NS rocker cover, the steel pads are all present, anything else I should be checking while the rocker covers are off?
Just in the process of a few top end jobs, main aim is to replace the fuel presure regulator with a 3 bar unit and pull the fuel injectors for testing. While I'm at it, I'm also planning to install an sc-power insulator gasket and replace the rocker cover gaskets.
Currently stuck trying to remove the trumpet base. I've removed the six bolts, and tried a reasonable amount of force, but it seems to be stuck solid. Any secret to removing it? I can't really see any easy way to get any leverage from below.
Also removed the NS rocker cover, the steel pads are all present, anything else I should be checking while the rocker covers are off?
The trumpet bass just lifts off.
It should be sealed with a smear of something like Hylamar and should just come up with a gentle tap. It does have a couple of dowels from memory so just gently tap around the edges while pulling up.
There isn't much to check on the rocker gear apart from the pads and if there is excessive play in the rockers or wear on the shaft which is easily seen if you remove it.
If the mileage of the car isn't excessive, probably best to keep it in place.
It should be sealed with a smear of something like Hylamar and should just come up with a gentle tap. It does have a couple of dowels from memory so just gently tap around the edges while pulling up.
There isn't much to check on the rocker gear apart from the pads and if there is excessive play in the rockers or wear on the shaft which is easily seen if you remove it.
If the mileage of the car isn't excessive, probably best to keep it in place.
Yep ^^^^^^^ that.
What can help you get some purchase if its really stuck, like if someone has been in there and sealed it back down with silicone is to refit the plenum top and then grab a hold of the inlet hose spigot. if its really stuck, GENTLY tap the inlet hose spigot with a soft object.
Gotta be a bit careful, but that should work.
HTH.
Edit: I have just finished making an insulator to go between the inlet manifold and the trumpet base from SRPB. I fitted one to my old 390SE and it did make a noticeable difference to plenum temperature. Might want to fit fibre washers under the trumpet base bolts when you replace them as that is a path through which heat will bleed up too.
Last thing, make damn sure to cover the now open 8 inlet runners with something to stop crap and washers going down there. I drilled up a 5mm plate of aluminium and I bolt it down to blank off the inlet whenever carrying out engine surgery. I saw my father once drop an aluminium washer into a Porsche 928S4 engine. Ouch. Just ouch.
What can help you get some purchase if its really stuck, like if someone has been in there and sealed it back down with silicone is to refit the plenum top and then grab a hold of the inlet hose spigot. if its really stuck, GENTLY tap the inlet hose spigot with a soft object.
Gotta be a bit careful, but that should work.
HTH.
Edit: I have just finished making an insulator to go between the inlet manifold and the trumpet base from SRPB. I fitted one to my old 390SE and it did make a noticeable difference to plenum temperature. Might want to fit fibre washers under the trumpet base bolts when you replace them as that is a path through which heat will bleed up too.
Last thing, make damn sure to cover the now open 8 inlet runners with something to stop crap and washers going down there. I drilled up a 5mm plate of aluminium and I bolt it down to blank off the inlet whenever carrying out engine surgery. I saw my father once drop an aluminium washer into a Porsche 928S4 engine. Ouch. Just ouch.
Edited by ed_crouch on Wednesday 7th August 08:14
Not sure what this was sealed with, but its f***ing solid.
I'm running an ACT carbon plenum so wouldn't want to put any stress on that, but might be able to refit the old plenum, if i can find the bolts and try that method.
Another thread mentioned using a jack, but i think this must be with the inlet manifolds and trumpet based removed from the car as I can’t really see location on the car where this would work with the inlet manifold in place.
might try removing the coil packs from behind the trumpet base to see if there’s any way to get more leverage from the back.
I'll definitely be sealing all openings into the engine, after a previous experience of dropping a bolt down the one of the inlets, and spending hours trying to retrieve it!
I'm running an ACT carbon plenum so wouldn't want to put any stress on that, but might be able to refit the old plenum, if i can find the bolts and try that method.
Another thread mentioned using a jack, but i think this must be with the inlet manifolds and trumpet based removed from the car as I can’t really see location on the car where this would work with the inlet manifold in place.
might try removing the coil packs from behind the trumpet base to see if there’s any way to get more leverage from the back.
I'll definitely be sealing all openings into the engine, after a previous experience of dropping a bolt down the one of the inlets, and spending hours trying to retrieve it!
Edited by angus337 on Wednesday 7th August 12:41
Thanks for the advice guys, finally removed it using the old plenum as above.
Only issue now Is that the 3 bar fuel pressure regulator has the wrong fitting lugs for bolting to the the fuel rail, it looks like this one.
The fuel connections are the right size, but It it does mate up.
Anyone tried the 0-5bar adjustable FPR sold by TVR parts?
Only issue now Is that the 3 bar fuel pressure regulator has the wrong fitting lugs for bolting to the the fuel rail, it looks like this one.
The fuel connections are the right size, but It it does mate up.
Anyone tried the 0-5bar adjustable FPR sold by TVR parts?
Hi Nick - you may wish to consider removing the whole of the rocker assembly off the head so you can examine the steel pads in detail - with them in place it is only possible to confirm the pads not missing.
It will only take 30mins and you will be able to satisfy yourself that cracks and craters are not present - this is the first sign of them braking up and can be replaced before they drop off and cause further problems.
I do this as a matter of course ever year and generally replace a couple I am not happy with - a couple of years ago had a pad break up and mushroom the valve stem which led to the heads off and a valve replacement and the usual while I am here refurb.
A high lift cam with pocketed pistons put a lot of force through this area and need a bit more TLC than a standard cam.
Andy
It will only take 30mins and you will be able to satisfy yourself that cracks and craters are not present - this is the first sign of them braking up and can be replaced before they drop off and cause further problems.
I do this as a matter of course ever year and generally replace a couple I am not happy with - a couple of years ago had a pad break up and mushroom the valve stem which led to the heads off and a valve replacement and the usual while I am here refurb.
A high lift cam with pocketed pistons put a lot of force through this area and need a bit more TLC than a standard cam.
Andy
BeastMaster said:
Hi Nick - you may wish to consider removing the whole of the rocker assembly off the head so you can examine the steel pads in detail - with them in place it is only possible to confirm the pads not missing.
It will only take 30mins and you will be able to satisfy yourself that cracks and craters are not present - this is the first sign of them braking up and can be replaced before they drop off and cause further problems.
I do this as a matter of course ever year and generally replace a couple I am not happy with - a couple of years ago had a pad break up and mushroom the valve stem which led to the heads off and a valve replacement and the usual while I am here refurb.
A high lift cam with pocketed pistons put a lot of force through this area and need a bit more TLC than a standard cam.
Andy
Agree with this. I'm just in the process of replacing all my rocker arms at the moment due to a pad having fallen off one of them with the resultant ticking. Although the other bank was quiet I took the shaft off to examine the pads and one fell off when I touched it, so definitely worthwhile.It will only take 30mins and you will be able to satisfy yourself that cracks and craters are not present - this is the first sign of them braking up and can be replaced before they drop off and cause further problems.
I do this as a matter of course ever year and generally replace a couple I am not happy with - a couple of years ago had a pad break up and mushroom the valve stem which led to the heads off and a valve replacement and the usual while I am here refurb.
A high lift cam with pocketed pistons put a lot of force through this area and need a bit more TLC than a standard cam.
Andy
I went with steel ones for replacement. They're a bit heavier but I'd rather avoid the possibility of future failures and since they're sitting on a shaft the extra weight isn't as big of an issue as it might first appear.
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