I need to measure your exhaust hole!

[chrisddl]

Not so painful as you might think. Let me give you the background.

I have a 1600K fitted with the single out of the side cat exhaust. Last year I purchased a CC comp exhaust (four out the side). To fit this exhaust, I need to open up the present circular hole into something resembling a rectangle, but before I do, I'd like to measure the size and position of a se7en fitted with the comp system. Therefore, If there's anyone in the Guildford area who would allow me to do that, I'd really appreciate it.

 

Thanks for listening

 

ChrisL

[Richard Price]

Chris,

I've done a few of these. I don't use a template. I cut the skin using a rotary burr in a die grinder. I start by offering up primary one to the cylinder head, and gradually cut away the skin until it will bolt up to the head (but the side skin is still quite close the the primary.

I then offer up primary two, and trim away at the skin until this one fits. Then, likewise three and four.

Once I can get all the primaries on to the head, I'll fit all the primaries into the collector (which finalises the position). I then mask up the side skin and then using a suitable straightedge (maybe a 10-13mm wide strip of metal or wood) I'll mark lines on the side skin parallel to the centres of the primaries. I'll then freehand the curved corners onto the masking tape. Then I remove the exhaust and trim the skin to these masked up lines.

 

 

[Irrelevant]

I currently have, languishing in my garage, a Caterham with a side skin designed for the 4 pipes but fitted with a single pipe. As I am in a good mood at present for some reason, if you want; you can come round and make a template up that you can fit round your single pipe - thus giving you the exact dimensions of the hole you need to cut

I am near J4 of the M3.

If you want to take advantage of this Christmas offer of kindness, the offer is open between 19:00 Friday and 12:00 Saturday. Blatmail for details.

 

[Myles]

Chris, I'm with Richard on this one... You are assuming that all 7s and cc exhaust are identical - they aren't.

 

The exhaust on my Caterham sits much lower the ground than many - and I suspect that's largely due to the second-hand primaries.

 

There are some pictures and instructions on my site (search for 'delbert' either in the 'what's on this site' link or via the Google search if that's working.

 

          🙆🏻 🙆🏻 🙆🏻 🙆🏻 🙆🏻

Alcester Racing

7s Ecosse™

^🙆🏻 🙆🏻 _🙆🏻 🙆🏻 ^🙆🏻

 

Alcester-Racing-Sevens.com

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[tiddy1]

Totally agre with above, I have never managed to find two exhaust holes in the same place or the same size, even on theoretically identical pipes, so unless you want to go really big then cut each pipe in turn

 

Simon

[chrisddl]

Hmmmm. And there was I thinking that all pipes should be identical in shape and therefore all holes will be same size and in the same place in the side skin.

Thanks guys for all your replies.

 

ChrisL

[Team Escargot]

Chris

I did this last year – Firstly I covered the area with masking tape and then I just offered up the individual pipes, marked with a pen and gradually increased the hole to suite using a jigsaw with a fine cutting alum blade. (Leave around 4 mm clear to the pipes) - No problems neat job.

Nick

 

[Mr Locust]

As others have said, fit the primaries one at a time and open the hole out gradually. Mark a where you want to cut to each time with a felt tipped pen.

 

I used one of these for a clean cut and minimal paint damage fettling of the edge afterwards (and I already had one).

 

Ian

 

Green and Silver Roadsport 😬

[micksmetafors]

I've just fitted a 4-2-1 Powerspeed and did it slightly differently. I fixed all 4 primaries to a block of wood to simulate the manifold as it would be on the head. I measured the the position on the primaries for the point they would pass thru the sideskin. Then created a template at that distance around the 4 pipes. From passing a pipe (not sure which one now) thru the original round hole it is then easy to position the template and draw the lines onto the masking taped area. I drilled a series of holes (3mm) and joined them up with a junior hacksaw blade before lightly grinding the opening smooth.

Not sure if this was slightly quicker than one pipe at a time (took about 3 hours in total) plus the rigmarole of water rail etc.

[chrisddl]

Many thanks for all your replies and I'll be having a go next weekend.

 

Thanks again

 

ChrisL

[GPBox]

I did something similar (or same) a month or two ago, a few photos here Exhaust hope this helps, lots of on/off with the pipes

have fun ! Graham

 

PS - I use a standard jigsaw with a new blade.........worked fine

 

Edited by - GPBox on 30 Nov 2009 21:38:07