Hi,

I popped this on my question with reference to heads but didnt really get an answer there so thought id do a thread to see if someone can help..

Ive purchased some new RCM headers as mine where broke...My car had its exhaust ports on the heads ported and the old headers ported..

The problem i have now is the new ports on the headers and alot smaller than the exhaust ports on the heads so will create a step/lip for the exhaust gas..Hear are the pics to show what i mean.

Hear you can see the size difference.


This is the gasket sat on the old headers


This is the gasket sat on the new headers



Do i need to grind back my new header ports to match the size of the ports on the head or will the lip not create an issue?

This is holding my up from getting my car back on the road, thing is im a little worried as dont want to wreck a £600 set of new headers.

Gavin

 

Are the headers for a classic? If so should'nt they be a direct bolt on? I cant see the pics as I am work but will have a look when i get home.

 

Tbho mate the port size on the manifold is the same size as the head so shouldn't create a step for gas to hit unless your heads are ported also in which case the headers may need gasket matching to the heads.

 

Hi,

The exhaust ports on the heads have been ported and are larger than the ports on the new headers, hence its going to create a lip

 

op already says heads are ported.
i'd open the manifold up to match gaskets (blue print) to keep a smooth exit for gases.

 

I would suggest porting the new headers then Gavin,easiest way is to get some clamps and grip the old gasket in position on the header and keep slowly working your way out until the port is the same size as the gasket hole with grinding stones until your about 1mm or so off and then get a smoother cut to finish the job up nicely,just remember to keep tapering down inside as not to create another lip deeper

 

He said the HEADERS where ported and didn't match the size of the head ports,no mention to head porting

 

my car had its exhaust ports on the heads ported?????? but didn't mention it?

 

He clearly says the old exhaust was ported and the new one is smaller and doesn't match head so unless I can't see some words on the post it doesn't say any where its had actual head porting done.
Correct me if I'm wrong of course.

 

MY CAR HAD ITS EXHAUST PORTS ON THE HEADS PORTED AND THE OLD HEADERS PORTED. 3/4th line down must of been that that you missed.

 

Lol, anyway moving on

Quite scared of doing this as worried im going to take them down the weld line!...Going to have to put quite a steep port on them i think..
Saying that anyone know where i could get them ported? saves me worrying about wrecking them, put the worry into there hands.

 

Harvey is your man

 

I did miss that bit mate,need to open my eyes I reckon,or go to specsavers
Back on subject I agree with above,speak to Harvey if your unsure as like you said you don't want to bugger up a expensive set of headers

 

would rcm not offer a service to port them and keep any warranty?

 

I would imagine your right there but by christ they would charge him for it,no offence to them as there work is second to none but they know how to charge for it

 

could be worth the extra in long run if they were to crack etc surely wouldn't be that much dearer could they? but then again

 

i have heard the Harvey has fallen ill, and not working at the moment

 

I thought he had been quiet lately,not good

 

if you do them yourself just be careful you don't go too thin is all you really need to worry about, grab your dremmel and take it slow, doing stuff yourself can be satisfying so go for it!

 

I'd be worried about porting them in stainless steel - unless the flange is very thick you are bound to compromise the strength of the welds.

 

Thats what im scared about, ill give RCM a call today at some point and see what they say

 

Called RCM today and there answer was to just bolt them up as they dont offer a porting service and have never had a need to.

Ive e-mailed Harvey so hopefully will have an answer soon.

 

Harvey is ill and not working at the mo. You might be better ringing Darren,who does alot of the work for Harvey, and asking his advice.

01325 480678, but he'll not be back at work until Monday morning.
He MIGHT also know when Harvey is likely to be back at work.

 

What have you done to my old headers LOL
Wouldn't it be easier to fix the old ones (depending on what's happened)

Enjoy porting out the new ones that stainless does (did not) not grind easily at all.