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7 port headed A series engine in a Mk3 Coupe

PostPosted: Wed Dec 03, 2008 12:34 pm
by manifold
Will post up some entries in here over time with regard to working on a 7 port headed A series engine.

Cheers,

David

Re: 7 port headed A series engine in a Mk3 Coupe

PostPosted: Wed Dec 03, 2008 2:24 pm
by manifold
some old photos of the Coupe from September 06, pre restoration

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Re: 7 port headed A series engine in a Mk3 Coupe

PostPosted: Tue Nov 15, 2011 4:43 pm
by DavidL
A bump for a dormant thread...

David, is this car up and running? Since I'm never going to start hacking up my Mk 3 to do a rear engined conversion, and am reticent about bonnet conversions, I've been starting to think about a 7 port head. I did try a forum search but "7 port" is apparently too common a term for the search function.

Also, if you've described the 7 port head conversion in more detail on the forum, could you point me at it, please? Thanks!

Re: 7 port headed A series engine in a Mk3 Coupe

PostPosted: Tue Nov 15, 2011 5:27 pm
by manifold
Hello David,

Yes I have my 7 port up and running. I've been using it in the Coupe as my daily driver for the last couple of years or so. Does about 35-40 to the gallon and is about 135 hp. I have made a special bonnet mould for 7 ports (or other cross flow heads inc KAD head) so that it fits under the bonnet.

I was sure I put some photos up somewhere on here. Let me see....

Re: 7 port headed A series engine in a Mk3 Coupe

PostPosted: Tue Nov 15, 2011 5:36 pm
by manifold
...well theres a video here for a start:

http://midasforum.dyndns.org/forum/viewtopic.php?f=60&t=443&sid=990e736944e5646458307b79f81eae3a&sid=990e736944e5646458307b79f81eae3a#p1479

Its running twin 40 dcoe webers via megasquirt (ignition only) at the moment.

Happy to discuss. ;)

Re: 7 port headed A series engine in a Mk3 Coupe

PostPosted: Tue Nov 15, 2011 5:48 pm
by manifold
Here is the link to the bonnet (which this one has an add on bump for the KAD cam carrier (not on the Coupe's)....although you might have seen the blue one in other photos.

http://midasforum.dyndns.org/forum/viewtopic.php?f=41&t=665&sid=d1c88b18d7458222cfa9f6aad7f67ed0&sid=74504fa6649c0982d54b076b6ef46dc6#p2460

Cheers,

David

Re: 7 port headed A series engine in a Mk3 Coupe

PostPosted: Tue Nov 15, 2011 6:56 pm
by DavidL
Thanks David, that's what I was after. I'm thinking ahead, I don't expect to have the funds for major changes for some considerable time. The reason I mentioned the 7 port was that I thought it might fit without changing the bonnet. However, I could live with a bulge!

Is there a big difference in cost between the 7 port conversion and the 16 valve one? I've had a quick look on Google and only found one 7 port head - it was Mini Sport who I found, listing a complete head for about £1700. Are there other possible suppliers for the 7 port, and is that price what you'd expect?

I presume there are other factors to consider, such as beefing up the clutch/gearbox/diff. What about brakes? Are there better options than vented Metro discs, and would I have to change to 14" or bigger wheels? I don't need to know all this right now, of course, but it's stuff I'll need to know, eventually.

Re: 7 port headed A series engine in a Mk3 Coupe

PostPosted: Tue Nov 15, 2011 7:54 pm
by manifold
Hi David. No probs.

Ok.

A cheaper option is the pierce manifolds 7 port. I got mine (i have a minisport iron and a pierce alloy head) inc plugs and valves for less than 1k delivered from USA. I think it's a better head than the minisport one. Med sell same head with a big lift in price!

I converted my brakes to Kad 4 pots and vented disks. Alloy drums on rear or Kad rear disc conversion. Brakes are single line twin cylinder with adjustable bias on pivot. It works wonderful without servo and is bloody easy to bleed too!

Don't go mad on clutch. I have a rally clutch and orange dot cover as I don't want to chew my thrust bearings.... Clutch is pre veto type with ultra light weight backplate and MED clutch arm kit. Ignition is Megasquirt so I can EFI it when I get round to it.

4 pin cross diff is best. Use Minispares NOT minisport one.

Do things in stages and feel each benefit ad you add it to the mix :)

I think wheels is a personal opinion. I have 13 inch on mine.

Please ask away. Happy to assist :)

A Kad engine is a bit excessive. Mine would cost in the region of 12k to build not including labour.

Re: 7 port headed A series engine in a Mk3 Coupe

PostPosted: Tue Nov 15, 2011 8:36 pm
by DavidL
I'm curious about the KAD calipers you mentioned; standard Metro calipers are 4 pot, are they not? Are the KAD ones just more efficient - and if so, how do they manage that?

Just had a look at the Pierce Manifolds website and see that they're currently selling a crossflow head with guides and seats installed for $1262, which is just under £800. Wonder if I could bring one back from California as hand luggage... :)

manifold wrote:A Kad engine is a bit excessive. Mine would cost in the region of 12k to build not including labour.

Definitely more than I'd want to spend!

Re: 7 port headed A series engine in a Mk3 Coupe

PostPosted: Tue Nov 15, 2011 11:45 pm
by manifold
Almost pays for the flight to the US!

standard metro callipers are 4 pot but the weigh a ton....seem to cause heat problems too in comparison to the alloy ones....i don't get any brake fade which I had before.....plus the hydraulic line is single line, as opposed to dual line. Because they are lighter there is less unsprung weight on the suspension. I am very happy with my KAD calipers.