tomti

over the next year or so im looking to slightly renovate my orion and play with the engine. i want to convert it from 1600 mfi to twin 40's

i dont know much about carbs so could someone give me an insight....

whats better, downdraughts or sidedraughts?

whats DCOE and DCNF?

would this be a relatively easy conversion?

what should i do fuel pump wise?


also, to go with the carbs, would it be ok to put a cam in it and if so which one?

id appreciate it if you keep the piss taking to a minimum, i do genuinely want help here

and before anyone says it, no im not gona turbo it cos thats been done to death and im not after massive power. more the induction noise than anything

cheers

xr-stu

may i be the first to sugest a zetec conversion instead! would work out cheaper to do, and would save you a small fortune on fuel!!

to answer your questions though, side drafts are often looked at as better than down drafts, because they offer a straighter path into the engine and suposedly make more power like for like.

DCOE and DCNF are the webber names/codes for their dide draft and downdraft carbs respectivly.

theres probably thousands of cvh's out there on 40s so will be a straight forward conversion when it comes to getting the bits. you'll be able to get a complete kit/setup with the carbs, manifold, throttle linkage and filters new or used off eebay or from the likes of demon theives, burton power or rally design. itll all bolt on easy as pie.

as for a pump, just a generic facet fast road pump will do the trick, along with a fuel pressure regulator and filter, all of which you'll get of ebay or DT/burton/RD as above.

cam wise, ive always used piper 285s in cvh engines and they always make really good power and torque. my advice would be to fit the cam BEFORE doing the carbs so you can be sure the engine will be able to run properly so run in the cam. fitting the lot at once will be headache if the car dont want to run properly on the carbs and you cant run the cam in correctly.

if it were my money id zetec it!

tomti

thanks for the advice mate. i dont want to zetec it really. call me strange but i like the cvh lol. im not bothered about fuel economy either as hopefully it will just be used as a fun car a couple times a week and for the shows etc.

have you any idea what sort of power output i'd be looking at with twin 40's, piper 285 cam, ported head and free flowing manifold and exhaust. i want to aim for approx 120-140bhp.

again i kow i could zetec it and get that power a lot easier but i wanna stay kinda old skool

tomti

also if i fit the cam before i fit the carbs, it seems theres 2 types of piper 285 cam kits. one for injection and one for carb. which should i go for?

xr-stu

i didnt realise there was a difference but i imagine itll be because the carb engine needs the extra lobe on the cam to run the std fuel pump, which obviously isnt needed for injection.

seeing as you wont be running the std pump, id imagine you'll be alright with either. call piper or burton to check though, i could well be wrong there!

and with the cam, a decent ported head with std valves, exhuast, and the carbs, id guess at it being around the 120-130 mark.

tomti

blinding mate. thanks a lot for the advice. appreciate it

xr-stu

make sure you double check about the cam mate! hopefully ive not missed anything. im sur ei havnt but someone will say if i have!

zetecapri

Doesnt matter, we fitted side draughts and the carbs got in the way of the fuel pump, totally wouldnt fit . Plated it up and fitted a low pressure electric fuel pump from an MGB GT. works a treat. Were using standard injection cam too, unsure if the piper one does have th elobe missing but its present on both the carb and MFI cvh engines.

RS_Rawli

as far as i'm aware thats always the case on a cvh, you have to fit an inline fuel pump as the lift pump wont fit with either of the DCNF DCOE inlet manifolds

mark_24v_wiring

iTrader: (1)

Totally correct about the fuel pump you cant run the std one had to be a facet or something.

I had a twin 40's setup years ago on a mk3 escort 1.6 cvh made 105bhp and 107 ftlbs and my carbs were nackered lol but it went like stink for what it was. Used to hold the rev limiter in 5th gear on the flat!!!!!

Make sure you have the carbs set up properly by some one who really does know what there doing it makes all the diff and make sure you get a good set to start with if your looking at a second hand set go see them if poss first before you buy and make sure every screw and every jet will undo trust me if they dont you can have real problems setting them up.

Go with the piper 285 and an adj pulley decent 4-2-1 manifold and good system (not ashley lol) will rot out in a few months.

Last tip find the 4 electrode bosch spark plugs that fit the cvh they give a better burn.

Paul Eggleton

Karl at Norris Motorsport is meant to be a demon setting up carbs. Give him a bell.

Daveysaff

iTrader: (9)

I've got a piper 285 cam for sale too

It's Czech Mate

http://www.pumaracing.co.uk/CVH.htm

I would be checking this guy out