carbs

essexcoupe3131

Hi All, Has any used a quick flow carb, was talking to them today and they jet the carb to suit the engine make up, I have a Edelbrock 800 Avs and it just too big for my engine and sucks juice OMG, might be lucky to be getting 8-10 miles per Gallon, they are stating that I would get a 35-40% more throttle response and much better fuel efficiency, there's 1 is 680 VS carb with

billet Ali bottom plate and metering blocks, not cheap but I have to think of the fuel long term,

I am considering changing the 3.5 in the 9" to 2.9 or somewhere around there as just under 4k revs at 60 miles an hour on the motorway and I want to do a lot of miles though in my insurance I am only allowed to do 3000 miles per year but at the price Iam paying for full cover ($780-00 NZ @ 150K)I can't complain

does anyone have the formula to work out this?



thank

terraplane8

Could you have 2 speedos and just swap them around?



4K revs at 60mph is 15mph/1,000 which sounds mighty low. You must have tiny wheels?

essexcoupe3131

I wish that was the case, have 18 boyds with (28.3/8" high) 285x 50x18 tyres not small by any stretch of the imagination

Thoughts



Mike

terraplane8

essexcoupe3131 wrote:

I wish that was the case, have 18 boyds with (28.3/8" high) 285x 50x18 tyres not small by any stretch of the imagination

Thoughts



Mike

What I was getting at is that it is impossible to only have around 15mph/1,000 with a 3.5:1 final ratio and tyres that big. I would have thought more like 24mph/1,000 rpm.



Calculating it out you should be doing around 2,500 rpm at 60mph. Maybe your tach and speedo are both wrong in different directions, compounding the error? They do need calibrating as there can be significant amounts of error.



Formula here: http://www.car-videos.net/tools/speedrpm.asp

essexcoupe3131

I have just had my speedo calibrated just before Xmas, a got a cert from them to show when appying to our Land transport aurthority, could the turbo 350 have a funny ratio in it?

i picked the 350 as you can pull the revs out hard in 1st should you desire and it wont shift into second not like the 400

I wouldnt know what 350 it is, all I know its a short tailshaft 1

I havnt had the tacho calibrated though

Mike

Lee ODell

The formula for RPM is: MPH X Gear Ratio X 336 divided by Tire Diameter.



60 X 3.5 X 336 divided by 28.375 = 2486.696 RPM



60 X 2.9 X 336 divided by 28.375 = 2060.4



Add RPM for any torque converter slippage.



Hope this will be of help.



Lee

Lee ODell

What engine size is in your car?



The Edelbrock 800 AVS is definitly to big for economy. I believe going to 2.9 gears with this carb will make MPG even worse. With a smaller cvm carb and the 2.9 gears gas mileage should increase significately.



In the 1980's my stock chevy with 327 engine rated 300 HP, 4 speed, 3.08 gears, stock exhaust, with a Carter 625 carb was getting 26 MPG at 55 MPH. With todays gasoline the mileage would be less. Width a 500 cfm carb the mileage would have been even better. When I bought the car it had a Holly carb. It was hard to start, drivability was terrible, and got 13 MPG. I change the carb with the Carter 625,and the car became a pleasure to drive.



Lee

essexcoupe3131

thanks guys, I have a 2300 stall installed in he car does this change things by much?



Thanks Mike

Lee ODell

Lee O'Dell wrote:

What engine size is in your car?



The Edelbrock 800 AVS is definitly to big for economy. I believe going to 2.9 gears with this carb will make MPG even worse. With a smaller cvm carb and the 2.9 gears gas mileage should increase significately.



In the 1980's my stock chevy with 327 engine rated 300 HP, 4 speed, 3.08 gears, stock exhaust, with a Carter 625 carb was getting 26 MPG at 55 MPH. With todays gasoline the mileage would be less. Width a 500 cfm carb the mileage would have been even better. When I bought the car it had a Holly carb. It was hard to start, drivability was terrible, and got 13 MPG. I change the carb with the Carter 625,and the car became a pleasure to drive.



Lee

I forgot to mention that my 64 El Camino did not suffer in the power department. It would go 90 MPH at the quarter mile drag strip and sip 26 MPG on the 50 mile trip back home.

essexcoupe3131

Lee O'Dell wrote:

I forgot to mention that my 64 El Camino did not suffer in the power department. It would go 90 MPH at the quarter mile drag strip and sip 26 MPG on the 50 mile trip back home.

I would be happy to get 15-20 as this goes with the game especially as this is supposed t be a 435 HP engine, holding a 10 -11 gallon tank, that's a pit stop every 150-200 miles that's a lot of coffee breaks LOL

Lee ODell

essexcoupe3131 wrote:

thanks guys, I have a 2300 stall installed in he car does this change things by much?



Thanks Mike

Hi Mike



The 2300 stall, will add aprox. 400 - 500 RPM to your cruising RPM.



Wow. 435 HP. Is it a big block or small block Chevy or some other engine? Now at my age, 150 - 200 mile pit stops are welcome.



You have a challenge changing a high performance engine to get good economy.



What I did to get your kind of HP and still get good MPG was to pull the 327 and trans. Then I installed a 350 Chevy with Magnuson 210 superchager (duel supercharger), twin dellerto side draft carbs, Schnider cam, Kenny Bell switch pitch turbo 400. With the same rear gears and same size tires, I still got 24 MPG. The supercharger fit under the hood to make the Elky a sleeper on the street.



If I had it to do over again I would have put a 1800 torque converter and changed the gears to 2.7 or 2.5. The engine made so much low end torque that the tires would break loose on hard take off, and do the same in second gear. Even when I put the largest tire that would fit, there was still a traction probem. The lower stall speed and taller gears would have put the engine in a lower torque range. Therefore, reducing tire spin on hard acceleration and improving acceleration.



I believe the result would have been another 1 or 2 MPG improvement.



Another big surprising plus. The engine ran much cooler with the supercharger.



I still have the supercharger and dream about putting it into a strepdown and adapting twin H type air cleaners to it some day.



Will you share more about your engine and car? I would like to see some pictures of it. With that motor in a light Essex it must be a very very fast car.



Have a good day, Lee

essexcoupe3131

This beast has supposedly 435 lbs of torque, Iam not trying to get the fuel economy in the 20s that would be a absolute bonus, as its hard to have both but 8-10 is just ridiculous even for me, and I don't have to pay for my fuel as it through my fuel account at work, you can tell the weeks when Iam putting up on some millage, it shows up dramatically



As I said at the beginning of this thread, I have been looking at a 670 trick flow carb and they jet it out for the cam, heads, manifold etc, I have heard good things down under about them but you guys would have seen more of these



The old girl can sit in the traffic for a hour and only hit 120 degs must be the big ass radiator these Essex s have and when we built it it had huge gallery's in it, though we had to put a lot of baffles inside to stop the thing blowing apart under pressure and it also has a victor juioner high volume water pump



thanks Mike

essexcoupe3131

Have just ordered a new Carb to go on her, should be done under in 14 days, lets hope it does the business

Mike

Lee ODell

Hudson308 wrote:

Wow... that's just Essexy!

I'll second that. It looks great.



Can you share some more pictures of your car?



Keep us informed on how the carb change works out.



I hope it works out to your expectations.



Have a good day. Lee

essexcoupe3131

Hi Guys, here it a picture of the coupe that the NZ HET club put into this years club Calender, its sitting in our garden at home, It shows the club with the help of David (essex28-1) is a little more open minded in this area, though I must say that when we turned up to the Nationals in it, at a vintage car club you could have heard a pin drop LOL



I will let you guys know how the quick fuel carb works out, as i said I have heard good things about them, a guy here has a Ford Cortina (small English car) with a 331 strocker in it, and was running in mid 12s but was having bogging problems with his 750 Holley, took 1 of these straight out of the box and went straight into the mid 11s, he was telling my friend that he got so use to it bogging when he drives it on the street( he has to give a good punch to get through it) that when he did it with the QFT he ended doing a 180 spin

he now treats it with a little more respect on the road

Lee ODell

Your car looks great.



Sorry I could not coment on your carb question. I didn't know anyone useing one. I asked my son, who is into drag racing, about them. He had heard of them, but didn't know anyone either that had tried one. Demon carbs seem to be the prefered carb in our area at this time.



The Quick Fuel information on the internet about them sounds good. Looking forward to reading about your results.



Thanks for sharing the pictures and information.



Lee

essexcoupe3131

Hi all, have got the carb and just spent the day re plumbing it all up, set it all up with Russel fittings,my supplier doesn't have all the stuff that is available that you guys have access to but hasn't come up too bad, started with dash 8 but was a bit over powering so had to change it to dash 6 though not as clean a system burred a couple of the fittings as was too tight to splash out for the ali spanners, was getting over the shock of all the components



I cant take it for a drive at the moment as don't have any plates to take it for a burn, though it sounds completely different, and I am very hopeful that this should sort out the over carburetor problems, 500 ks too go and we can put her on a dyno to do the final fine tuning



I have just set up the sound system in the car and will have to burn in the speakers it will help keep down the noise of the exhaust system LOL



Mike

essexcoupe3131

Have got the carb on Phew what a difference from the piece of Sh** Edelbrock AVS carb straight out of the box and real responsive , set all the timing up and altered the springs slightly on the dizzy

running 10 on the crank and 28 on no vacuum dizzy with 6AL

Impressive

Going to set up rockers tonight as we can see a flicker on the vacuum gauge which is telling us some of the valves are out plus I have a ticky 1

and the old girl isn't quite ready to light up the tires straight off the yet mark



Mike

essexcoupe3131

We have a big Mopar only day at the drags in end March, saw you guys talking about that the Essex/Hudson are now owned by Chrysler so asked them if I can run, they emailed me back

Absolutely



Don't know what she would run but was hoping to get in high 13s to low 14s

I suppose only time will tell especially if I can get all the horses out of the old girl that Edelbrock was supposed to supply with this engine



I used to run flat 15s all day long in my 57 Chev with a 350 hp 327 and a slipping auto, i am picking an supposedly extra 20% hp more and a lot lighter coupe should help the ET's



Mike

essexcoupe3131

Hudson308 wrote:

435 honest hp in a 2900lb (?) car with 3:50 gears should get you at least in the low 13's. All depends on how well you hook up, but I bet you hit the traps doing 120. Hey, waitaminnit... these are all "English" measurements. Do you guys actually run quarter mile drags down there in kiwi land? :eek:

Always have done and will to continue to, some places have a 1/8 mile but a waste of time and effort just start getting the adrenaline running



Mike

Unknown

Can anyone tell me how to post a thread



any help would be appreciated

essexcoupe3131

you can either post a replay like you did or if you want to start a new thread go to the beginning where you can choose what part of this forum at the top of page and there is a button to start new thread

if you want to post some photos once you have opened new thread go to advanced and you can manage uploads from there

hope this makes sense



Someone else might chime in

Mike

essexcoupe3131

Did some more work on the carb last night as was flat spotting at the drags, and couldn't believe the difference a different nylon cam can make on the accelerator pump the flat spot disappeared completely, a simple and cheap part can make so much difference went up in the power valve as well from 5.5-6.5

but may reduce this back this weekend just to see what its like as on the dyno the 5.5 was running a perfect line on the graph



Mike