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DIY cylinder head ... just wondering
02GF74 - 2/11/06 at 02:41 PM

just wondering; let's say someone had a cnc milling or even a simple milling machine.

How feasible would it be to make your own cylinder ghead, let's say 16 crossflow.

The tricky part is the internal waterways, oilways and ports so the head is made in 2 halves, upper and lower in order to be able to machine the internal cavities and then bolted up with a gasket in between.

16 valve crossflow head anyone?

What do you reckon and problems envisaged?


balidey - 2/11/06 at 03:10 PM

is all i have to say... good luck


MikeR - 2/11/06 at 03:21 PM

hasn't it already been done ...........
check out burton's page.

600 quid for an ali 8 valve bare head.
2500 for a bda/bdx 16 valve head.

good luck, you'll have a lot of people jealous (me included).


liam.mccaffrey - 2/11/06 at 03:30 PM

best of luck
I think its possbile to do without resorting to casting techniques which is what I think you're getting, but not easy

I would love to have the time to have a go at something like that.


you have me thinking now


StevieB - 2/11/06 at 03:42 PM

quote:
Originally posted by zilspeed
Let's take the example of the good old A Series.

BMW K motorcycle head is so compatible in respect of bore centres and head studs that it can be made to fit.

Now - find a head that will fit the xflow in a similar fashion and off you go.

OR

Just fit a zetec complete


So can you get a bellhousing to go with the A-series, and what gearbox? Presumably an old MG should be pretty much ready to go?


iank - 2/11/06 at 03:53 PM

Can fit an MG Midget gearbox, or a series 9 with a bellhousing from Frontline

http://www.mgcars.org.uk/frontline/gearbox.htm

Not as cheap as just shoving in a zetec.


Prez - 2/11/06 at 04:03 PM

I would expect the most difficult bit would be getting the port and gas path geometry right, as this is such a performance critical element of engine design. Modern cylinder head gas flow paths are complex to machine even with fairly specialised equipment, that said, with enough time and patience anything is possible....


Confused but excited. - 2/11/06 at 04:47 PM

quote:
Originally posted by liam.mccaffrey
I would love to have the time to have a go at something like that.



I'd love to have the bloody equipment!


liam.mccaffrey - 2/11/06 at 05:10 PM

i bet you could do somthing interesting without cnc stuff, like the old days. could practice converting a single cylinder bike engine to 4 valve or similar


Volvorsport - 2/11/06 at 05:10 PM

didnt the FVA cosworths have ports machined into the head with straight tube , if you machined the valve seat area with enough meat on you could easily weld some tubes on , hard parts would be lining up cam bearings , valve guides.

TVR speed 12 engine was basically fabricated by hand .

BDA has seperate cam carrier bolted to the actual head , so your not too far away in principle , id pick a more modern bottom end to base it on .


liam.mccaffrey - 2/11/06 at 05:12 PM

volvo, you aggree though that it is possible to cobble somthing together


DIY Si - 2/11/06 at 05:29 PM

With time, it is possible, but getting it to work is perhaps the hard part. What about choice of cams? Would any/most 4 valve cams do, or would the timing have to be very engine specific?


StevieB - 2/11/06 at 06:10 PM

quote:
Originally posted by Volvorsport


TVR speed 12 engine was basically fabricated by hand .




And engines don't get much more impressive than that one!

So powerful, they had to cut it in half for road use


Volvorsport - 2/11/06 at 06:19 PM

itd be interesting for a project , altho i reckon i can get a 8v to flow the same .

theres a B20 nocking around (pushrod 8v) at 236 hp , from carefull port work (epoxy filling) etc .


JackNco - 2/11/06 at 07:43 PM

ok ive read the whole thread and everyone seems to have missed a very important question here...

WHY HE HELL WOULD YOU BOTHER!!!!

surely it would be easier, less time consuming and nearly as cheap to just swap out the ending for a 16v engine?

John


ettore bugatti - 2/11/06 at 08:10 PM

In dutch, but pictures says it all.
http://home.tiscali.nl/modelengines/36ccviercilinder/de_cilinderkop.htm
Apfelbeck wrote a book on constructing your own cylinder head
http://www.apfelbeck.nl/


DIY Si - 2/11/06 at 08:39 PM

Good point raised by Volvo, if you get the ports roughly right, you can always "flow" them with epoxy resin to put the necessary radii in place.


MikeRJ - 2/11/06 at 09:32 PM

quote:
Originally posted by DIY Si
Good point raised by Volvo, if you get the ports roughly right, you can always "flow" them with epoxy resin to put the necessary radii in place.


Not the exhaust ports though, unless there is some miracle epoxy that can take that kind of temperature.


DIY Si - 2/11/06 at 09:38 PM

Fair point that! But if yu do it right, you could probably make the exhaust port easier/straighter than the inlet, and have less shaping to do.


liam.mccaffrey - 2/11/06 at 09:39 PM

quote:
Originally posted by JackNco

WHY HE HELL WOULD YOU BOTHER!!!!




that is the whole point, you don't need to, and its probably not the best/cheapest/easiest thing to do.

but i bet if i spent the next year building a cylinder head i'd learn a shed load more than any book could tell me


DIY Si - 2/11/06 at 09:48 PM

And think of the bragging rights! Did you make that car? Yup and half the engine, from scratch, with out any training!


liam.mccaffrey - 2/11/06 at 10:42 PM

biggest braggin rights ever


JackNco - 3/11/06 at 12:03 AM

lol ok bragging rights IF it works and u get any improvement in power. f it just blows up then i wouldn't be bragging about it. im the same with computers *why did you do that* * because i could* but that just seems like SOOOOO much effort for no reason.

John


Marcus - 3/11/06 at 08:43 AM

quote:

*why did you do that* * because i could* but that just seems like SOOOOO much effort for no reason.



That, to me, is what Locosting is all about. Not because it's economically viable, not because it's the easy route. It's why I built my chassis (twice) and didn't buy one.
It's the reason I modified other parts rather than buy off the shelf.
It's the reason my car only cost £1500 to put on the road rather than 6-7k.
That's why, when people ask "is it a Caterham or an original Lotus" I can just grin and say nope!
It's the Locost way!


Syd Bridge - 3/11/06 at 09:00 AM

It would be far easier to make some patterns and cast exactly what you want.

Sand cast inside a closed box with a vacuum pump on, so no porosity whatsoever.

Cheers,
Syd.


02GF74 - 3/11/06 at 09:19 AM

quote:
Originally posted by JackNco

WHY HE HELL WOULD YOU BOTHER!!!!




no reason whatsover; was a question if it was possible if you have the right equipment at home; the same could be same about making your own car when you can buy one.

the theory behind the question was cost - if you had access to mill/CNC, the alloy would not be that expensive plus it would be a challenge. Time ofcourse would be the biggest "hidden" cost that for most of us building on here is free.

So it seems in theory it is doable; my concerns will be the join between the two halves and whether the head would be strong enough so as not to warp.

I suspect in the end, after many hundreds of hours, it probalby burst on the first outing .. but still would be interesting project.


NS Dev - 3/11/06 at 09:45 AM

be good to pick an engine where it hasn't been done before, otherwise you will always just see the cheaper option of buying what is already available.

Cosworth bda is not cheap but cheaper than making your own 16v xflow head


JackNco - 3/11/06 at 04:34 PM

quote:
Originally posted by Marcus
quote:

*why did you do that* * because i could* but that just seems like SOOOOO much effort for no reason.



That, to me, is what Locosting is all about. Not because it's economically viable, not because it's the easy route. It's why I built my chassis (twice) and didn't buy one.
It's the reason I modified other parts rather than buy off the shelf.
It's the reason my car only cost £1500 to put on the road rather than 6-7k.
That's why, when people ask "is it a Caterham or an original Lotus" I can just grin and say nope!
It's the Locost way!


No i get building ur own chassis, but this just seems like going out of your way to make life hard........


Marcus - 4/11/06 at 10:02 AM

Each to his own, I guess, but sounds fun to me