Alloy heads for cross flows ?

[Mark H]

Sometime ago i was surffing around a site that had an advertisment for alloy heads, now my problem is that i can,t remmember where that site is anyone know anything about these or the site?

[Graham Perry]

I don't know if they have a web site but Burtons in Essex certainly do one. About GBP 800 I believe

[Blatman]

Burtons..........

[greg]

I think these come from the states - david bean engineering IIRC.

 

 

 

Greg, Q 86 NTM (Green 185BHP XF)

[edmandsd]

Can someone please build a crossflow with one of these and an alloy block. With an 84mm crank you'd have 2.2lt plus these heads allow for really large valves. I reckon you could get R500 power with this set up and an all up engine weight of around 75kgs.

[cdg]

I know where there is such an animal for sale! (Or was last time I looked). This one's only (!)a 2ltr though, and was built for a hillclimber that used to own my all-steel 1700.

Burtons built a 2.4 not so long ago which made prodigious power...and I seem to remember John Wilcox building a 2.4 (albeit with a cast iron head) about five years ago which was exhibited at the Autosport show in Birmingham.

 

I'll see if it's still for sale.

Chris.

 

[Gavin]

Marc,

 

The piercemanifolds.com American website shows the alloy heads which are I believe are the same as imported by Burtons.

 

Does anybody know the weight saving ?

[Peter T]

The alloy heads that Burton supply offer a considerable weight saving over the conventionable cast heads, i am not exactly sure of the weight differance between the two, but my conversation with their technical man led me to believe that it was around 1/3 of the weight. These heads can be fitted with rather large valves(1.750"inlet, 1.500" ex). As i allready have a cast iron head with these size vavles, it seemed a rather expensive and pointless exercise to go down this route, and bolt it on a cast iron block! The only way i see to build an ultra light X-Flow using this combination, is to use a Early BDA/BDR block, as the current new blocks that Burton supply are BDG blocks that have a slightly different head bolt arrangement on the exhaust side, also by the time you have paid someone to machine the block to accept the pushrods and cam followers, it outweighs the huge financial cost to build a light X-Flow. Unless it was someone elses money ,i would rather build a new BD series engine as most parts are available now.

 

C7 PWT X-Flow all Steel

Life begins at 40(00rpm)

[Graham Perry]

I spoke to someone who had one of these and he reckoned on an 8.5 kg weight saving

[Dan J]

Try: -

 

Warrior Automotive Research Ltd

Uckfield

East Sussex

TN22 1QL

Day: 01825 764833

 

Ask for Richard, they may be able to help.

 

Dan

Fury 1400 K

151bhp 😬

[Peter Carmichael]

A single 1.75 inch valve has a valve perimeter of 139.6mm

 

Two 32.5mm inlet valves in a 16v head have a valve perimeter of 204.2mm

 

A single 1.75 inch valve has a valve area of 1552mm ^2

 

Two 32.5mm inlet valves in a 16v head have a valve area of 1659mm^2

 

On both important metrics such a head is significantly outperformed by a diddy-valve 16 valver. The low lift flow particularly will be bad and this will be reflected in the cam profile to hit any particular power level. Such an engine would be *peaky* compared to any 16 valver of equivalent peak power. I won't mention the mass of the valve train and how that relates to rev potential and reliability...

 

*thumbup*253 bhp, up and running *thumbup*New boingy bits

[edmandsd]

I accept your rationale Peter but as they say 'there's no substitute for cubes' and I wouldn't describe a 2.2lt crossflow as peaky. The head flow is likely to limit power at high rpm in a large capacity derivative such as suggested although the mid range punch from an engine such as this would be considerable.

 

Appreciate the point re heavier valvetrain compared to 16v set up although tubular pushrods and std rockers are very light. Also you wouldn't want to rev an engine like this as high as a 16v or standard capacity crossflow so reliability in this area shouldn't be a concern.

 

It would be a nice alternative though, original and potentially very light with around a 30kg weight saving over standard.

 

I reckon an all singing and dancing slide throttle injected 2.2 lt crossflow such as this should give around 230bhp at 7,500rpm (This is comparable with HTR's current 2.2lt 8v Pinto's) In fact they're entering a 2.3lt Pinto powered Escort at Brighton this year which has 250bhp..............the engine doesn't weigh 75kgs though !)

 

 

 

 

[AMMO]

2 valves per cylinder will never make the horsepower as 4 valves per cylinder. Duckworth knew this in the early sixties (Forty, FOUR-O!, years ago). Otherwise he would have made the DFV with two valves and pushrods.

 

I saw a Puma engine last week that was de-stroked to 1600 cc that made 229 bhp. The guy that built the Puma was a hot rod champion who raced Crossflows. The best engine he ever raced produced 188 bhp.

 

I ran a race team that had 2 valve pushrod engines for many years. You could say that I became the Roger King of my field. We kicked ass big time even against riders with superior machinery. Once we got four valve engines nobody came close.

 

I honestly do not mean to offend anyone but I cannot understand the affection for something that is obviously from the Ark. I'm not saying they don't give people great enjoyment and there may even be some "underdog" element which I certainly enjoyed when we raced two valvers. But pushrods? You can't be serious.

 

Yours, completely baffled.

 

 

AMMO

[edmandsd]

I think the point here is that we're comparing a 2.2lt 8v engine with a 1.8lt 16v engine, where the 8v engine is potentially lighter than the 16v equivalent but could give similar peak power - 250bhp k's excepted !

 

I've never pretended an 1800cc race crossflow can make the same as an 1800cc 16v race engine. Apparently SBD are now getting near on 260bhp from their 1600cc 8 injected Vauxhall engine running race fuel !

 

I think the other point is that you could get 2.2lt's from a crossflow but not say a k.

 

 

 

 

 

Edited by - edmandsd on 1 Aug 2002 21:54:39

[cdg]

I think I have to agree with everyone!

 

Whilst I do have a place deep in my heart for the old (dog) crossflow, mine is about to be dispatched to pastures new. I investigated building a large capacity motor with huge valves and pistons the size of dinner plates, but in the end even I came to realise that it would never make the power of (say) a good 16V VX engine, and would have been an incredibly expensive undertaking even though I would have saved on professional build costs by building it myself. It would still have been cheaper than what some guys are spending on their ex. Metro engines though...

 

Couldn't bring myself to fit a 16V engine though; all those little valves bouncing up and down and belts here there and everywhere. So the next engine to grace my Mallock will have only 3 valves (or possibly 4), no belts, no pulleys, no springs, no pushrods, no cam followers (no cam!) but will make at least 240bhp per litre (360bhp per litre for one of my options). Oh, and it weighs 2/5ths of bugger all.

Chris.

 

 

[AMMO]

Chris

 

I'm curious.

 

Is it a rotary or a stink wheel (2-stroke)? Something else?

 

Yours, even more baffled than before.

 

AMMO

[edmandsd]

I know what you're up to Chris and i'm amazed no one's thought of this before...............or maybe they have and we just haven't heard about it. Imagine if you did a Chris Allanson and fitted two............still be lighter than one of our engines aswell !!!!

[AMMO]

Someone put me out of my misery and tell me what Chris is up to.

 

AMMO

[Violet Elizabeth]

I honestly do not mean to offend anyone but I cannot understand the affection for something that is obviously from the Ark.

 

Perhaps the gentleman would like to step outside (to ChitChat) and say that

[greg]

Peter,

 

Dave knows about 16v vs 8v and no one is suggesting tuning an XFlow for pure performance reasons. Its just some of us have a soft spot for them! Dave seems very fond. But at the end of the day his engine is a 16v and pretty powerfull.

 

Oh, can anyone give be the burtons partnumber for their alloy heads, I want to see how much they cost! You ned the part number on thier website, there is no catalogue.

 

One of the reasons I have one, apart for historical ones is that pound for performance they are quite cheap.

 

Greg, Q 86 NTM (Green 185BHP XF)

[cskip]

Part No is : FB800 and according to the Burtons Cat. price is £750 + the dreaded.

 

Below that is a Head for a BDG - £2900 + dreaded. Makes the X-flow ali head seem cheap!!!!

 

Clive.

 

X-flow and proud

 

 

Edited by - cskip on 2 Aug 2002 10:45:26

[Peter Carmichael]

My comments are nothing other than bemused mumblings.

 

I find it bizarre that there is an alloy crossflow head on sale in this day and age. £750+dreaded is a lot of money for something that can be easily bettered by standard production 16 valve head. I got lucky, but the head for my engine cost me 100 quid cash to a dodgy geezer. I saved the expenditure for the valvetrain, where obviously a 16valver has more bits and more weight. The redeeming feature of the K is that its OHC direct actuated design is much simpler than anything involving pushrods rockers etc. I am not particularly tied to the k-series as a technology, but I do like the idea of being able to compare technologies before diving into a project, hence a quick fag packet comparison of breathing apparatus to suggest that the big valved crossflow will be asthmatic against some fairly ordinary 16 valvers. If I was undertaking an upgrade from a crossflow, I would be looking closely at the chance to move from carbs to throttle body fuel injection as a primary objective. Having taken the trouble to move to FI, the engine choice is almost irrelevant and is determined by engine mounts and bellhousings which are easily sourced.

 

I am clear that there *is a substitute for cubic inches*. When those cubic inches are deployed in a suboptimal fashion they can easily be bettered in all regards by paying attention to the fundamentals.

[cdg]

AMMO,

 

Check your inbox...

 

Chris.

[elie boone]

What about the Vegantune head then ?

it does'nt matter how old an design is, if it's good it will be a fast and nice engine. The Bugati 3 valver is 70 years old but it is still a fantastic engine and in the type 35 can surprise a lot of hot tin tops.

 

[AMMO]

Chris has put me out of my misery. I now know what he is up to and can sleep tonight. Thank you Chris.

 

Elie

 

If Iwas a rich man I would have a Bugatti 35 and probably a Fraser Nash as well. But a Vegantune head, the same as a Lotus twin cam is still a two valve design and so has to be considered antiquated (but OK for some). In fact I can't see why you would want to operate the valves with twin overhead cams when pushrods at the rpm the engine produces max bhp are probably more than adequate and lighter too. Bloody hell, I'm actually defending pushrods now. What next?

 

How a bout a Rhone Gnome rotary aero engine with flapper intake valve and sidevalve exhaust. The crank stays still and all the other gubbins go round and round. That's 90 years old. Maybe even better than a Bugatti engine (only 70 years old . Pah!).

 

AMMO