kangaroosa Posted April 22, 2005 Report Share Posted April 22, 2005 Well its come time to sort out some carbs for my 5K. I was thinking of purchasing a Redline Intake Manifold to suit either one or two Weber 40 DCOE carbs. Has anyone seen or used these manifolds - If so, are they any good or worth the money? Weber DCOE's have the same bolt pattern as Dellorto DHLA's from what i've read. (Undecided as yet as to which brand of carb to go with) I'll speak to the bloke tuning my car to see what he reccommends as far as brands and number of carbs anyway. Quote Link to comment Share on other sites More sharing options...
TRD ke70 Posted April 22, 2005 Report Share Posted April 22, 2005 we use Dellorto's on the rally car because they Atomize the fuel better and deliever better torque down low, say that the webber is a good carb, it produces better top end power. we use ly over manifolds before we stood the engine upright and found that with a little work they flowed quite well. the webbers and dellorto's do have the same bolt pattern. hope that helps Quote Link to comment Share on other sites More sharing options...
Super Jamie Posted April 22, 2005 Report Share Posted April 22, 2005 some also say that dellortos are a heap easier to tune than webers redline would be one of the better brands of manifold to use. they're usually up over $200 new, but can be picked up second hand for half that, if you're paying over $140 then keep looking Quote Link to comment Share on other sites More sharing options...
Redwarf Posted April 22, 2005 Report Share Posted April 22, 2005 I have Webers, but only because the Dellortos I had fouled on my custom extractors. They both do basically the same job. Quote Link to comment Share on other sites More sharing options...
kangaroosa Posted April 22, 2005 Author Report Share Posted April 22, 2005 I'm thinking 1 carby should be enough. I would like to keep the cost down and also keep it simple. Unless anyone thinks 2 would be better (and not just to say that i have twin carbs), keeping in mind that its my everyday car. I read a thread on here that the Dellorto's come with a few different venturi sizes. Anyone got a suggestion as to what size venturi's i should be looking out for. Most of the engine specs should be listed below to aid you in making a suggestion. Quote Link to comment Share on other sites More sharing options...
kangaroosa Posted April 23, 2005 Author Report Share Posted April 23, 2005 I just visited the Dyno shop and the bloke reccommends a single Weber 40 DCOE with the smallest venturi's possible. He can always machine the smaller venturi's bigger. Apparently there are more parts available for the Weber compared to the Dellorto's. He can get different sized venturi's for the weber, whereas the Dellorto's have to be machined to the preferred size. So Weber shopping it is then. Thanks for the Help guys. Quote Link to comment Share on other sites More sharing options...
Redwarf Posted April 23, 2005 Report Share Posted April 23, 2005 I perhaps would have thought a single 45, particularly with those cam specs you put up earlier (that is the cam you are running?). Smallest venturis you can get I think are 28mm, and they WILL be too small for your motor. my 3K has twins, and i run 32mm chokes, and the 2t-G has twins with 34's (I think). However, smaller venturi's will keep the fuel bill down. True, Dellorto parts are about twice the price of Weber parts. Quote Link to comment Share on other sites More sharing options...
kangaroosa Posted April 23, 2005 Author Report Share Posted April 23, 2005 I perhaps would have thought a single 45, particularly with those cam specs you put up earlier (that is the cam you are running?). Smallest venturis you can get I think are 28mm, and they WILL be too small for your motor. my 3K has twins, and i run 32mm chokes, and the 2t-G has twins with 34's (I think). However, smaller venturi's will keep the fuel bill down. True, Dellorto parts are about twice the price of Weber parts. Yes - The Crow Cams page is the specs of the cam i am running currently. Firstly - What is the difference between a 40 and 45 DCOE. I would assume the 45 is for a bigger motor than the 40, but is it the venturi's that are different or not? I guess what i'm looking for is the car to go well - i've spent about $2000 to date on this motor and all the little bits and pieces that go with it. So i want to finish it off with a nice carb setup. If a single carb will give me this -then that is the path i will take. So in your opinion, will a single carb do that for me. I was getting 10km/L with a full rich 32/36 DGV weber (before it was tuned). What is your mileage with the twins on your 3K? I don't mind the car using a bit more fuel (with bigger venturi's) if its making reasonable power, compared to smaller ones. I just want it reach somewhere near its full potential. The reason he suggested buying a carb with the smallest venturi's was to ensure that he could get it set up. What i mean is - He can always machine the venturies out to a bigger size if need be. But you can't take a 32mm venturi and make it into a 28mm venturi. Sounds like the round about way of doing it, but its just to ensure that i don't buy a carb that is too big for my car. As i found that a 32/36 DGV was too big in the venturi's. Sorry this was so long, but i want to get my head around this before i start shopping. Quote Link to comment Share on other sites More sharing options...
TRD ke70 Posted April 23, 2005 Report Share Posted April 23, 2005 As i found that a 32/36 DGV was too big in the venturi's. why?? if there to big you're going to be in trouble with side draughts. personally i'd be putting twin 40mm side draughts on with 32mm venturis, i used to run these on 4k's, so on a 5k it should be prefect. one choke per cylinder you can't go wrong. Quote Link to comment Share on other sites More sharing options...
kangaroosa Posted April 23, 2005 Author Report Share Posted April 23, 2005 (edited) As i found that a 32/36 DGV was too big in the venturi's. why?? if there to big you're going to be in trouble with side draughts. personally i'd be putting twin 40mm side draughts on with 32mm venturis, i used to run these on 4k's, so on a 5k it should be prefect. one choke per cylinder you can't go wrong. Sorry - I meant the dyno shop said that they are too big in the venturi's. The sentence was meant read "As i found OUT that a 32/36 DGV was too big in the venturi's". I think i'll be going somewhere else to get the side drafts tuned. The car went in with 56rwkw (full rich weber and glazed rings) - Then once they were finished tuning it, it had 48rwkw (Hrmmm, Somethings not right). What was your mileage like with the twins on the 4K? The final thing with twins - Is it hard to get them to meet pollution regulations etc? I would assume not. If they are tuned professionally that is. So what your saying is that one side draft carb will have 2 venturi's - both of the venturi's are 32mm each - So 4x32mm venturi's as a complete set if i ran twins. It's just that i've never dealt with side drafts (only down draft - which have had different sized venturi's from primary to secondary). Is the standard mechanical fuel pump suitable to run the twins? Edited April 23, 2005 by kangaroosa Quote Link to comment Share on other sites More sharing options...
Super Jamie Posted April 23, 2005 Report Share Posted April 23, 2005 a dcoe40 has 40mm throats, a dcoe45 has 45mm throats seriously, i'd be using twin 40s with 28-32mm chokes. the whole idea of swapping to sidedrafts is to make the inlet tract as efficient as possible. just one dcoe on a single manifold is only going to be marginally more efficient than a single downdraft. 28mm chokes are quite hard to get hold of from what i've heard a mate of mine had a single 45 on a 4k, he said it was alright, but changed back to the modified stock carb he had because the single really wasn't that much better no, the stock fuel pump won't be good enough. you'll need a high volume low pressure electronic pump and a pressure regulator, set it to 4.5psi don't think you're going to get good fuel economy from sidedrafts, or that you can do it "on the cheap". they're good carbs, some might even say the best, but you certainly get what you pay for Quote Link to comment Share on other sites More sharing options...
kangaroosa Posted April 23, 2005 Author Report Share Posted April 23, 2005 I know deep down that twins are the best option - At the moment i'm still doing the maths on both the single and twin setup. The Damn Government and Petrol taxes aren't helping either. I just filled up for $1.15/L premium ulp. Single carb = Roughly (Manifold $250ish from memory?? + Carb $250 + Carb Tuning and Dyno $150) = $670 Twin Carb = (Manifold $270ish + 2xCarbs $500 + Fuel Pump and Regulator??? + Carb tuning and Dyno $200ish) = $1500+ (Its worth as much as the motor and about twice what i'm willing to spend on the car). I'm seriously leaning towards the single sidedraft setup after hearing what you just said Jamie. Damn reality sucks. I know if i spend $1500 on twins and then double my fuel bill, i'm not going to be very happy. So i think i just talked myself into a single and see how she goes. Then the final step is to pull the engine out for the 3rd time in 6 months to have it re-ringed as she is using oil. The engine builder suspects glazed rings from my 32/36 DGV weber running way too rich. Ohh well, more money. Thanks again to everyone who helped me out with their advice. On a final note- If this was your motor (everyone), how many rear wheel kW would you be expecting or be happy with? I'm a little dissapointed with the 56rwkw that it pulled on the dyno. Quote Link to comment Share on other sites More sharing options...
trd Posted April 23, 2005 Report Share Posted April 23, 2005 glazed rings isn't caused buy running to rich, my guess is its got chrome rings fitted (bastards of things) your fuel bill wouldn't double. twin delortos are quite good on fuel. u don't have to get it dynod either. most of the tuning for delortos is done without a dyno. if u get the correct jets all that has to been done is balancing the carbs & setting the idle screws if your looking for a twin delorto set with manifold,linkages & air cleaners i maybe able to help next week (off a 4k) Quote Link to comment Share on other sites More sharing options...
TRD ke70 Posted April 23, 2005 Report Share Posted April 23, 2005 As i found that a 32/36 DGV was too big in the venturi's. why?? if there to big you're going to be in trouble with side draughts. personally i'd be putting twin 40mm side draughts on with 32mm venturis, i used to run these on 4k's, so on a 5k it should be prefect. one choke per cylinder you can't go wrong. Sorry - I meant the dyno shop said that they are too big in the venturi's. The sentence was meant read "As i found OUT that a 32/36 DGV was too big in the venturi's". I think i'll be going somewhere else to get the side drafts tuned. The car went in with 56rwkw (full rich weber and glazed rings) - Then once they were finished tuning it, it had 48rwkw (Hrmmm, Somethings not right). What was your mileage like with the twins on the 4K? The final thing with twins - Is it hard to get them to meet pollution regulations etc? I would assume not. If they are tuned professionally that is. So what your saying is that one side draft carb will have 2 venturi's - both of the venturi's are 32mm each - So 4x32mm venturi's as a complete set if i ran twins. It's just that i've never dealt with side drafts (only down draft - which have had different sized venturi's from primary to secondary). Is the standard mechanical fuel pump suitable to run the twins? reading everything that you have done to the engine, i think that the carb is thing that is letting the engine down,you've got 2" sports system, a head job( :P ) big valves, and a decent cam. WHATS THE THING THAT IS MISSING?? good carburetion!!!!! if you drive the car the same way as before the fuel economy shouldn't change if it's tuned right, you could even find that it'll get better. your engine will breathe better, it'll deliver power smoother and should rev harder. and use an other dyno shop because these guys must be idots if they think the venturis are too big. what's your cam spec's, 0480" lift seams way to much, that works out to be 320 at the lobe, maybe try a smaller cam, is it a race car or road car? Quote Link to comment Share on other sites More sharing options...
Xany Posted April 23, 2005 Report Share Posted April 23, 2005 hehehe.....if you don't want those delortos......i'll might take them off your hands for the right price.... thats if kangaroosa doesnt want them. Quote Link to comment Share on other sites More sharing options...
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