Plenum, Rockers and Trumpets - Observations and Comments
Discussion
Hi All
I've finally got my hands dirty, literally, and removed the rocker covers, plenum and trumpet base. I'm going to replace the rocker gaskets, but is there anything else worth doing whilst it's all in pieces? What's the best method to clean everything up? I assume white spirit down the bore holes wouldn't be the best idea
I couldn't shift one of the pipes attached to plenum near the air intake, and the other looks like it has corroded. Had to remove the other end which resulted in gush of coolant! What are these two pipes for? As far as I can see all the pads are still on the rocker arms, but one or two are slighly scored on the top, anything to worry about?
All observations and comments welcome.
I've finally got my hands dirty, literally, and removed the rocker covers, plenum and trumpet base. I'm going to replace the rocker gaskets, but is there anything else worth doing whilst it's all in pieces? What's the best method to clean everything up? I assume white spirit down the bore holes wouldn't be the best idea
I couldn't shift one of the pipes attached to plenum near the air intake, and the other looks like it has corroded. Had to remove the other end which resulted in gush of coolant! What are these two pipes for? As far as I can see all the pads are still on the rocker arms, but one or two are slighly scored on the top, anything to worry about?
All observations and comments welcome.
I did a little mod that may be usefull.
Junk the metal twin tube heater pipes that run down the offside rocker cover. Renew hoses from heater, through nearside inner wing, run new hoses under inlet manifold and reconnect up using a couple of elbows to the inlet manifold and longer hose to the rad/hose junction.
Neatens up that area and makes replacing the rocker cover and gasket easier,
Junk the metal twin tube heater pipes that run down the offside rocker cover. Renew hoses from heater, through nearside inner wing, run new hoses under inlet manifold and reconnect up using a couple of elbows to the inlet manifold and longer hose to the rad/hose junction.
Neatens up that area and makes replacing the rocker cover and gasket easier,
The two pipes under the plenum where coolant came from are not needed. They are just a basic throttle heater, a mod for Range Rovers running in icy cold weather apparently. Definately not needed on a TVR. Would seem some cars had them fitted others didnt. Best thing to do is on both hoses is to just blank them off. Place a good fitting bolt into the end of the hose and then fasten tight with a small hose clamp. That or just join the two together, byepassing the plenum. The bolt method does provide a good bleeding point though when re filling with coolant.
The marks on top of your rockers is nothing. The wear if you have any will be on the shaft where the rockers work. Probably easiest to check if you take the shafts off and just slide each rocker to one side. Unless you are high mileage i suspect they will be ok.
Happy polishing.
The marks on top of your rockers is nothing. The wear if you have any will be on the shaft where the rockers work. Probably easiest to check if you take the shafts off and just slide each rocker to one side. Unless you are high mileage i suspect they will be ok.
Happy polishing.
carsy said:
The two pipes under the plenum where coolant came from are not needed. They are just a basic throttle heater, a mod for Range Rovers running in icy cold weather apparently. Definately not needed on a TVR. Would seem some cars had them fitted others didnt. Best thing to do is on both hoses is to just blank them off. Place a good fitting bolt into the end of the hose and then fasten tight with a small hose clamp. That or just join the two together, byepassing the plenum. The bolt method does provide a good bleeding point though when re filling with coolant.
Happy polishing.
I didn't mean that.Happy polishing.
I meant to reroute the heating pipes through the valley!
No pic available as engine out!
carsy said:
The two pipes under the plenum where coolant came from are not needed. They are just a basic throttle heater, a mod for Range Rovers running in icy cold weather apparently. Definately not needed on a TVR. Would seem some cars had them fitted others didnt. Best thing to do is on both hoses is to just blank them off. Place a good fitting bolt into the end of the hose and then fasten tight with a small hose clamp. That or just join the two together, byepassing the plenum. The bolt method does provide a good bleeding point though when re filling with coolant.
The marks on top of your rockers is nothing. The wear if you have any will be on the shaft where the rockers work. Probably easiest to check if you take the shafts off and just slide each rocker to one side. Unless you are high mileage i suspect they will be ok.
Happy polishing.
Interseting, thanks. I'll get those blanked off straight away then. I presume I don't have to bother bunging up the metal pipes on the plenum?The marks on top of your rockers is nothing. The wear if you have any will be on the shaft where the rockers work. Probably easiest to check if you take the shafts off and just slide each rocker to one side. Unless you are high mileage i suspect they will be ok.
Happy polishing.
The car is 93 and has done 80,000 miles, probably more like an actual 70-72k depending how long the speedo has been vastly over reading. The only history I had prior to me buying are a few service stamps and the MOT's. So I couldn't be sure what's been changed, hence having a quick look. I'll take the shafts off and have a look for any wear. Thanks again.
Might be worth investing in a thermal gasket , as you have already taken the plenum off.
About £15, and a lot of people here reckon it brings the plenum temperature down considerably...
Obviously also look at upgrading trumpets(/intake manifold/throttlebody) if relevant to your grand plan and funds allow...
HTH
Dom
About £15, and a lot of people here reckon it brings the plenum temperature down considerably...
Obviously also look at upgrading trumpets(/intake manifold/throttlebody) if relevant to your grand plan and funds allow...
HTH
Dom
BillC99 said:
For the sake of removing another 8 bolts I would remove the rocker shafts and check the rocker pads. When I removed mine I found that 1 pad had cracked down the middle and part of it was missing!! It was not really visible while the shaft was attached.
Agreed, worth a look now whilst everything else is out. I just hope I can remember how to put everything back together again 
domV8 said:
Might be worth investing in a thermal gasket , as you have already taken the plenum off.
About £15, and a lot of people here reckon it brings the plenum temperature down considerably...
Obviously also look at upgrading trumpets(/intake manifold/throttlebody) if relevant to your grand plan and funds allow...
HTH
Dom
Thermal spacer purchased...can't really justify anything else right now. Already upgraded the HT leads, plug shrouds, coil, ignition amp, stepper, dizzy cap, rotor arm, flame trap, ACT breather hoses, ACT plenum elbow and a gallon of white spirit About £15, and a lot of people here reckon it brings the plenum temperature down considerably...
Obviously also look at upgrading trumpets(/intake manifold/throttlebody) if relevant to your grand plan and funds allow...
HTH
Dom
finestjammy said:
Thermal spacer purchased...can't really justify anything else right now. Already upgraded the HT leads, plug shrouds, coil, ignition amp, stepper, dizzy cap, rotor arm, flame trap, ACT breather hoses, ACT plenum elbow and a gallon of white spirit
That's all very well but none of those items make it go faster!
Gassing Station | Chimaera | Top of Page | What's New | My Stuff