Rebuilding rear of engine - couple of questions

[caymanr26]

Afternoon chaps – after a bit of help/advice if possible

Am in the middle of stripping and rebuilding the rear end of the engine in my raider (carb, inlet, exhaust manifold, turbo, pipework, air filter, intercooler, header tank etc) its been rebuilt previously but is a bit rough round the edges, Ill start a blog when I get 5 mins but currently all of my time is taken up cleaning engine parts!

Anyway I have a few questions (though im sure this will grow!) based on comments/pictures Ive seen on here but need to clarify exactly what I do

Firstly, there is a breather pipe coming off the side of the lobster back with a one way valve inserted which leads to a metal pipe that goes into the back of the turbo – is this pipe needed? I cant see it fitted to other people’s cars as I can see that people blank off that pipe on the lobster back. Also if I don’t need this pipe any advice on what I can use to block the hole on the turbo?

Secondly, I notice from pictures that people buy silicon hoses without the overboost switch on the hose leading from the Turbo – Do I not need this switch? I need to order new hoses so shall I order without? If I don’t fit the switch what would you recommend doing to the wires for it – can I remove them or is it better to hide them away. Trying to tidy the bay up a bit – there are pipes and wires everywhere!

Lastly, Im removing the pipework that comes off the side of the anti-perc fan – im also then removing the sensor/valve thing that the hose goes on to – this again has a wire leading to it. So my questions are, will this cause any running problems? What does it do? Can I again remove the wires?

Thanks in advance for any help!

Cayman

[Goobie]

I'm guessing the pictures of other people's engine bays you've seen are running the cup mod set up.

You don't need to have the one way valve set up really, unless you going for the 100% original look. As for the valve, you can just put a short bolt into the back of the turbo elbow, maybe put a bit of exhaust sealant on the thread before screwing it in just to be sure its sealed if you feel the need.

Over boost switch, again not needed unless your going for the factory look. Just neatly tape off each end of the wire connectors so they can't short them selfs on anything and cable tie them out the way safely and same goes for the Perc fan wires if you decide to remove that to.

The job of the Perc fan is to blow cool air over the carb and into the main boost hose to help the fuel sitting in it from evaporating in the heat and hot weather to solve the hot starting problems they suffer from in the summer months, but a few good pumps on the throttle when turning the engine over helps solve this. :)

[caymanr26]

thats great - really appreciated

sorry - I didnt explain the perc fan bit very well - I meant what is the purpose of the valve thing mounted onto the bulkhead that the pipes lead to?

Have you got any pics of the Cup Set up or any info about it?

[Goobie]

I don't have a picture to hand but can dig one out later unless some one got one to hand and wants to post it up.

Ok, I know the section you mean, it has a pipe coming off it going into the boost hose.

It's locked shut till the engine off and the Perc fan kicks in, then opens to allow the cool air to be more directly blown into the boost pipe to flow into the carb inlet elbow for the same reason I've said above buddy.

Little tip, thats usually the first place to check if you get a boost leak as that section can be a common problem.
:)

[Wallace]

I can't see if the pictures are there or not cause using my phone, but hope this helps:agree:

http://www.rtoc.org/boards/showthread.php?t=4756

[caymanr26]

Ah cheers lads - that's a great help

How do you usually block the unused carb outlets?

[caymanr26]

Got another question - anyone have any pics of the turbo support brackets - my car hasn't got any and when the previous owner fitted a rainless manifold it cracked within days - I'm fitting the manifold but obviously don't want it to crack again so need to support the turbo correctly - any advice would be great

[Wallace]

Forgive me if I'm not understanding properly - but turbo brackets?

Unless there is something out there that I don't know about (quite likely:wasntme:)

There is a bracket for the manifold as per pic, but other than that the turbo is fixed to exhaust manifold also as per pic (sorry not the best!)

[Wallace]

.....

[caymanr26]

cheers wallace

I recieved one of the downpipe support brackets yesterday from CGB

CGB also advise though that there are 3 other brackets - 1 mounts to the air box (havent got an airbox fitted though so forget that one)
1 mounts to a heat shield and the final one is the turbo support bracket - they said its very rare that a car comes in with one of these fitted as usually they have been disgarded by previous owners when working on the engines - they are looking for one for me now - last thing I want is the weight of the turbo causing the manifold to crack again

[Brigsy]

Assuming you have an original cast manifold, you wont need the turbo support bracket. No body runs them unless totally o.e, the manifold wont crack without it.

My tungy has one on and it makes turbo removal a ball breaker.

[caymanr26]

That's the problem - I've got a stainless tubular manifold going on and don't want it to crack again - admittedly there was no down pipe bracket fitted previously whereas I will be fitting that.

So if fitting a turbular manifold do you think that support bracket is required?

[Brigsy]

Just bin the tubular manifold mate;) the standard turbo support wont be enough anyway.

[caymanr26]

Seriously??

Surely it can't be that bad? Is there any way round it then? Uprated mounts etc? CGB said they have had one fitted for about 6 years without any issues

[Brigsy]

As far as im aware nobody has seen massive gains, if any at all with a tubular manifold - the only time i would use one is if your radically modifying the engine - i.e. efi, massive turbo and huge power goals. All i hear are tales of cracked manifolds, and even slower spool time in some cases lol

[Goobie]

They may of had one fitted for that long, but doesn't mean it was driven anywhere in that time :laugh:

Jokes aside, your need to get creative and make up a support bracket to take the weight of the turbo charger then there will be less stress pulling down on the manifold. :)

[caymanr26]

Well Ive ordered all of the brackets - there are quite a few of them!

http://i.ebayimg.com/t/RENAULT-5-GT-TURBO-SUPPORT-BRACKET-FROM-GEARBOX-TO-TURBO-UNIT-/00/s/NzY4WDEwMjQ=/$(KGrHqV,!pEF!YYD59E3BQG7)ogI6g~~60_12.JPG

http://i.ebayimg.com/t/RENAULT-5-GT-TURBO-SUPPORT-BRACKET-FROM-GEARBOX-TO-TURBO-UNIT-/00/s/NzY4WDEwMjQ=/$T2eC16h,!ykE9s7tyfbGBQG7)tGO!g~~60_12.JPG

Also in the picture above of the downpipe support there is also supposed to be a metal bar that attaches to block which I havent got so Ive ordered that too

[Wallace]

:laugh::laugh:

I knew 1 of the 3 existed:scared:


Go for it:agree: bracing it can only be a good thing:agree:

[caymanr26]

Bob at cgb is adamant that I now have all of the brackets and that there is no way the exhaust or turbo can move about so I'm gonna fit the stainless manifold - if it cracks after all this then sod it ill remove it

[Nad-5GTT]

Bob at cgb is adamant that I now have all of the brackets and that there is no way the exhaust or turbo can move about so I'm gonna fit the stainless manifold - if it cracks after all this then sod it ill remove it

:agree: this is what I'll do with mine. I made a bracket that bolts from the elbow down to a gearbox bolt. Good luck