David M Posted April 3, 2006 Share Posted April 3, 2006 I am starting to think about what throttle bodies I will put onto the K4 head I picked up from the MG auction.... a few questions... (basically trying to reduce the cost) 1) Why are bike throttle bodies so much cheaper and are any suitable for the K-series? 2) Is there any real competition to Jenvey/QED direct to heads? 3) Has anyone come up with the adapter for the new one piece cosworth roller barrel set up into the K-series, as discussed in previous threads...? (Ok not really reducing cost on this one ) It just amazes me how expensive throttle bodies are when they seem mechanically quite basic...... I guess it must be a volume thing.... Cheers David GF04RCE.... every day is a Caterham day!!!! He heee!!... pictures here. Problem is every day seems to be a GT4 day too...!!! Link to comment Share on other sites More sharing options...
Big Brother Posted April 3, 2006 Share Posted April 3, 2006 Bike throttle bodies are cheap because you have to do "stuff" to make them fit a car derived engine. If your able to make/modify manifolds, tig weld and have access to a friendly machine shop, then they're a bargain. Steve SE7EN-UP! Incorporating the Caterham Links Database Link to comment Share on other sites More sharing options...
AMMO Posted April 4, 2006 Share Posted April 4, 2006 David As Steve says you have to make the bike throttle bodies fit. Its easier to buy something that fits out of the box than messing around. If, however you are in a messing around mood, I have a set of throttle bodies from a Suzuki GSXR that were replaced with some race kit bodies. Yours for a ton if you want them. AMMO Link to comment Share on other sites More sharing options...
David M Posted April 4, 2006 Author Share Posted April 4, 2006 I just can't help feeling that there is a huge margin put onto throttle bodies for what they are.... is there any reason why they are cast and not plastic moulded, they don't have to deal with heat there function seems simple.... unrestricted air flow direct to head, throttle mechanism, horns and filter..... or am I over simplifying things... force of habit!!!!! David GF04RCE.... every day is a Caterham day!!!! He heee!!... pictures here. Problem is every day seems to be a GT4 day too...!!! Link to comment Share on other sites More sharing options...
David M Posted April 4, 2006 Author Share Posted April 4, 2006 Cheers Ammo, but I am staying away from the messing around at the moment although if you come up with an adapter for that Cosworth single piece roller barrel to fit a K-series........ 😬 Oh and congrats on the 300bhp+ Emerald run..... David Link to comment Share on other sites More sharing options...
oilyhands Posted April 4, 2006 Share Posted April 4, 2006 Bike TBs are also OEM fitment, so they have a limited appeal in the bike market and have to be adqpted to fit a car engine. Most TBs you see for sale for non bike engines are after market, their price reflects their suitability and the original price paid. TBs are generally fitted on hard used engines, plastic TBs would suffer with distortion when heated, this could affect the throttle plates efficacy, if the plates stuck open you would be in serious shinola. Typically TBs have to be heavily reworked at the manifold face to fit the inlet ports, plastic is not the ideal material for this. Any attachments to the TBs are normally screwed on, again securely fastening items to plastic is not an easy/reliable thing to do. I think TBs are a little expensive given their relatively straightforward construction, if there were massively cheaper alternatives we would all be using them. There is also the jewellery affect. Oily Link to comment Share on other sites More sharing options...
Jason Plato Posted April 4, 2006 Share Posted April 4, 2006 its the second time you have asked why they are so expensive 😬 because its what people are willing to pay ! Plus the cost of manufacture is not realy that cheap I imagine. There are numerous small precision machined parts in them and a lot of machining to the faces of the bodies. Plus the quantities are probably quite small in the grand scheme of things. if yu think there is a huge margin in things like bodies - then what about exhausts at £600 - "only" a bit of bent tube (?) or suspension dampers - "only" an alluminium tube with some rubber seals but one comapny can charge £40 each and another can charge £600 each. Or what about a caterham chassis - "only" some cds tube brazed together and wrapped in a thin ally panels but its three times the cost of a Tiger Avon kit . Its value added - thats why my pies cost me 6p to make and you pay 87p to eat it 😬 Link to comment Share on other sites More sharing options...
AMMO Posted April 4, 2006 Share Posted April 4, 2006 David Why do you want an adaptor to fit the Duratec bodies to a K? Why don't you just get the roller bodies for the K? Or better still get a Duratec to fit the Duratec TB's :-) Personally I'm not a fan of roller bodies. I would prefer the DTH bodies any day of the week. Oily would know what is best for your application. Thanks for congrats on 300 bhp Duratec (not fitted with roller bodies BTW). AMMO Link to comment Share on other sites More sharing options...
David M Posted April 4, 2006 Author Share Posted April 4, 2006 Visited Hyperion at the weekend and just developed an unhealthy obsession with them Yep spoken with DVA and know what I will likely do when funds permit, I just can't help thinking throttle bodies are alot of money for what they are..... David Link to comment Share on other sites More sharing options...
David M Posted April 4, 2006 Author Share Posted April 4, 2006 Ok starting to sound like a stuck record about the cost thing, time to accept it..... Dave you should see me later in the year, I have a proper k4 casting head this time for you to weave your magic..... and will go for the direct to head THB etc..... David Link to comment Share on other sites More sharing options...
Nifty Posted April 4, 2006 Share Posted April 4, 2006 You could always use a set of swanneck throttle bodies as originally supplied on VHPDs .. they are cheaper than the DTH options .... ........ and it so happens I know where a set lay unused *tongue* Keep off the straight and narrow 😬 Edited by - Nifty on 4 Apr 2006 19:27:03 Link to comment Share on other sites More sharing options...
S47zz Posted April 5, 2006 Share Posted April 5, 2006 Try to get a set of Lotus Esprit 45mm bodies, I bought a new set still wrapped up in the packaging, and with the original factory set up sheet for £75 at a Lotus parts fair, I've used 'em on a zetec, but I'm sure they would fit a 'K' Link to comment Share on other sites More sharing options...
David M Posted April 5, 2006 Author Share Posted April 5, 2006 Could you use 45mm THB, I thought they were usually 43mm for the K-series and what would the effect be...? Sorry Nifty think I'll pass on those....... stick them on ebay.... they'll go for at least £200 minimum...... Link to comment Share on other sites More sharing options...
metal mickey Posted April 5, 2006 Share Posted April 5, 2006 Ask yourself a simple question - can/could I make them cheaper and remain solvent in business 🤔 And besides, nothing is expensive if you make good use of it - I learnt that personally when buying hand tools. Link to comment Share on other sites More sharing options...
charlie_pank Posted April 6, 2006 Share Posted April 6, 2006 All FSI bikes I know of have throttle bodies, therefore they're OEM and relatively cheap. Link to comment Share on other sites More sharing options...
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