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X flow head - rebuild / unleaded conversion etc prices
Nickctp - 13/4/13 at 09:20 PM

Evening all,

I'm just about at the head stage now in my rebuild. Before I go off down to my engine builder, does anyone have a ROUGH idea of what I can expect to pay for having the following done?

Light port & polish
Unleaded conversion
Skim if reqd
New valves and guides

Do the valves need changing anyway with the unleaded conversion?

Cheers

Nick

Confused but excited. - 13/4/13 at 09:50 PM

I got mine done by Lyons in Swansea, less than half what Burton wanted.

teegray19 - 14/4/13 at 09:54 AM

Skim 30
Guids 7-10pound each
Cast iron head shouldnt need the hardned seats, not sure of cost mine had them.
Porting pointless as the crossflow ports are hugely oversized as standard.

MikeRJ - 14/4/13 at 10:29 AM

quote:
Originally posted by teegray19
Skim 30
Guids 7-10pound each
Cast iron head shouldnt need the hardned seats, not sure of cost mine had them.
Porting pointless as the crossflow ports are hugely oversized as standard.


The xflow head will definitely need hardened valve seats to run unleaded for any decent length of time, as will almost any cast iron head that does not have hardened valve seats from the factory.

Porting is certainly not pointless on the xflow either. The idea of porting is not to increase the size of the ports but to improve the shape, and there is plenty of scope to improve the standard ports.

Confused but excited. - 14/4/13 at 10:50 AM

quote:
Originally posted by teegray19
Skim 30
Guids 7-10pound each
Cast iron head shouldnt need the hardned seats, not sure of cost mine had them.
Porting pointless as the crossflow ports are hugely oversized as standard.


Why skim 30 thou? You only need to take off enough to make it flat. It could even need more.
What the head i s made of, iron or alloy is irrelevant, it's what seats are fitted that counts, as Mike said.
Porting point already covered by Mike.
There are some very good books on X-Flows and the tuning there of.
Ford's Kent Crossflow Engine by P&V Wallage.
Modifying Production Cylinder heads by Clive trickey.
Tuning Escorts and Capris by david Visard.

johnemms - 14/4/13 at 02:44 PM

FORD Crossflow (Iron head) Gas Flowed cylinder head | eBay
CNCHEADS - Race specification Gas flowed cylinder heads Ebay Link
I would like one of these

teegray19 - 15/4/13 at 06:38 AM

£30 for a head skim, the xflows like induction turbulance that is actually caused by the standard sand casting marks in the ports. And the ports are huge unless your doing a tricked out head and bottom end. You will spend £££ porting and polishing and may see 1/2hp gains.

Getting it on the road for the suns far more important.

Ive got any bits you need for sale now Nick first start up of the new engine went well.

teegray19 - 15/4/13 at 06:46 AM

New valves set me back £16 each plus VAT but they are a good fit no radial movement. Should have had guides fitted but for another £120 Il love with a puff of smoke.

redturner - 17/4/13 at 06:28 PM

Cost of these mods can only be based on what you expect from the engine. Basically the only things that will make an engine rev faster is the work done to the head and the cam fitted. A steel crank and rods will only make it last longer. The standard crank in a x-flow will stand to rev as far as you want for a limited time as will the rods. I have a full race head for a x-flow used with a BCF 3 cam and this was revving to 7500 in my single seater. A good proffesionally prepared head will cost up to £1000 for a x-flow. I have one for sale, race ready, c/w rocker gear on steel posts and pencil thin bronze guides. £500

[Edited on 17/4/13 by redturner]