Removing the plenum to paint, what to watch out for?

[Gasman GT3]

This weekends project is to remove the cam covers, chargecooler, and plenum to give them a new coat of paint. When I picked up a set of gaskets from SJ the other day Steve did that sharp intake of breath thing when I told him what I was doing and warned of poor running if I wasnt careful when removing the backplate. I intend not to remove the throttle bodies just the back plate, but would just like any tips on making the job pain free.

Also tips on the best technique for sanding back the highlights on the cam covers and plenum cover would be much appreciated.

One final thing do I need to de-pressurise the fuel system before removing the plenum nozzle?

[cjtpb13]

Prior to removal you should de-pressurise the fuel rail. Easiest way is to disable the fuel pump ( generally the fuse or relay can be pulled ) and run the motor till she runs out of fuel.

I still have no idea why everyone sucks their breath in thing when it comes to the removal of the throttle bodies. Is is not that complicated to place all back together as long as new gaskets are used.

[lotus4s]

The reason why is that the throttle bodies are flow matched together on a bench with the backing plate and supposedly removing the backplate can disturb that setup. It is specifcally mentioned in the manual. That being said, I've done it a few times and not had a problem.

You do need to be careful not to disturb the settings on the linkages between the throttle bodies.

[Gasman GT3]

Blimey, the paint is a begger to remove, Nitromors hardly touches it!!! If anyone else has done this what did you use to remove the paint?

[dodge1979]

Well...when I did all mine I used.....nitromorse! And a scraper...and sand paper....and more nitro....took a while, but get it all off or.the result will.show up whats underneath..but it was only the chargecooler that was difficult..the cam.covers were easy...the I wiped it all down with thinners, then used the extremely vht primer..apparently good for.2000 degrees, hotter than the standard vht one...let it dry as per instructions, then top coated with the extremely vht wrinkle red, again higher temp than standard vht if I remember...and baked in a litle oven I use for powder coating to get the wrinkle finish..

Leave it a day if you can then I used a new stanley blade and cut the raised mouldings of the covers etc clean of paint, ie angle the blade so.it slices under the paint and cuts a.clean edge, you wont damage the alloy finish unless yiu dig it in forcefully..

As.for the chargecooler, the plate on top with the lettering got.the.same treatment, but more carefully to leave the lettering which is only fractionally shallower, in red. Any imperfections were removed with very fine sand paper.. Et viola....

[Gasman GT3]

Thanks Darren,

Yeah, the cam covers are not too bad, but the chargecooler is a real pig, gonna have a go with the Dremel tomorrow with a brass wire brush attached.

have you got any piccies of how the wrinkle finish looks on yours mate?

[dodge1979]

I have..since .moving last weekend im without broadband...just on my phone for time bein...i must admit I burnt the chargecooler , so had to redo it..but the cam covers r bloody good! Next year ill.change the.colour though....does this mean ur off the road this weekend? Not sure if dave is havin a tea n biccy meet...

[Gasman GT3]

Yeah, not had much time to work on the car so taking advantage of the long weekend to get this done, as the engine paintwork was letting the car down. Mind you there were times today when I wish I hadn't started.

Is there an easy way of de-pressurising the fuel system without starting the engine. I see there is a test nipple on the end of the fuel rail but not sure how it works?

[dodge1979]

Tobe honest I didnt depressurise the system first...just have some rags ready its not all that bad.just watch out when you unscrew the fuel to plenum nozzle hoses that you dont bugger up the nut and when refitting make sure they go in square and you dont cross thread them, as its only alloy its easy to do but annoying to remedy!

[Gasman GT3]

Cheers Darren. I think the test nipple is like a tyre valve, so first I am going to try pressing it in with a screwdriver while holding a jug over it. Thanks for the tip about the fuel feed to the plenum, looks easy to bugger up, I will be careful.

[Gasman GT3]

Well it is finally done and all back together again, and not looking bad if I say so myself. I did cheat with the backplate by painting it in situ not wnting to strip the induction system for fear of upsetting settings, but the rest were fully stripped and repainted in VHT wrinkle red finish, which I got from Frosts.

For those who need to do this the VHT paint is a good match for the factory colour. I wasn't very popular with SWMBO when the curing process in the oven caused the whole house to stink of paint fumes, even with the kitchen window wide open and the extractor fan on full, beware of this.

Below are a few piccies of work in progress and the finished job.

Plenum as it was

Cam covers and chargecooler being stripped

Cam covers curing in the oven

Finished parts ready to refit

All back together

The other side, complete with a new set of Magnacore KV85 ignition leads

[CHANGES]

Nice,

[jonwat]

Nice, is it a good wrinkle finish & how does the colour compare to the original??

[dodge1979]

Good stuff there! The vht red is not quite as orange a red as the original if I remember right? But it is a.close match and does look good though. I also left my plenum rear attached when I did mine for the same reasons, but ilk be taking it off this winter and changine the colour...im liking the s300 grey now me thinks!

[esprit s2]

How did you get away with putting them in the oven??!!! My missus would go ballistic!

[Bibs]

They look lush, nicely done

[rogerch]

How did you get away with putting them in the oven??!!! My missus would go ballistic!

Yeah !! my mum used to go right off finding engine bits in her oven. Seem to recall the missus was not too happy about a calliper rebuild on the breakfast bar either.

But I've had no complaints in 25 years now.

[Gasman GT3]

How did you get away with putting them in the oven??!!! My missus would go ballistic!

She did. I did the cam covers one evening and stank the house out and so was forbidden from doing the rest. Solution, do it during the day when she was at work

One of the many benefits of working from home. What she don't know wont hurt her.

In case anyone wants the recipe its 1 hour at 95 degree C. I think Gina's patience was tried as this is the second time in a month I have had to use the oven for Automotive purposes. The other week I had to perform surgery on on of the 300C's headlights to change the lens to save potentially £670 buying a new one, after a block paving tile buried itself deep in one on the M42.

Headlight in the oven to melt the silicone sealant holding the lens on

The wrinkle finish seems dependant on what the ambiant temp is in the initial drying phase and also what you are painting. The cam covers are very wrinkley but the chargecooler is smooth, very much like the original.

As Darren said it is not quite as orange, but pretty damn close. I did notice in Frosts catalouge that they do a Chevy Orange VHT brush on smooth engine paint, and I think I am right in saying Chevy orange is also close to the original Lotus colour.

Edited April 17, 2012 by gasmangt3

[nigeninja]

Nice one Ade that looks really good

[dodge1979]

The wrinkle depends upon the heat. I used a hot air gun first to get a tight wrinkle, then cured in an oven...i have a little camping type.one for caravans so no fall outs.over funny smelling chicken dippers!

[jonwat]

As Darren said it is not quite as orange, but pretty damn close. I did notice in Frosts catalouge that they do a Chevy Orange VHT brush on smooth engine paint, and I think I am right in saying Chevy orange is also close to the original Lotus colour.

Rover vermilion is a spot on match for the original, so you can, if you wanted a perfect match, overspray the wrinkle paint with that which you can get from Halford's.

Does look nice though, well done that man.