40 DRLA Dellorto's suited for engines up to?

[Jordy/DVK]

 Since I can't afford myself some IDA's now nor in the near future, I'm considering 40 Dellorto's.
 I find those Dellorto's a nice and affordable alternative, but what's the biggest engine you can use them for,
 keeping in mind that the engine should still be capable of turning considerable revs/min...

 Jordy

[Diederick/DVK]

My thoughts exactly, 40 dells on tall manifolds can look big too.

Also, i think 1915cc is about max, displacement around 2 litres, 2054cc and 2007cc also seem to work with 40 dells. I'm guessing 36, 37 venturis are about right 

[Sander/DVK]

Something about 2000cc with 32 or 34mm venturie's.
Tell us, what are your plans??

[Jordy/DVK]

 I don't have any plans yet, but I'd like to know if 40mm are good ti fill considerable cc's...

 And converting them to 45 DRLA's is that an easy conversion? And what are those 45 DRLA's capable of? The same as IDAs?


 Cheers... Jordy

[Diederick/DVK]

Anyone else?
I'm sure he's not waiting for clubmembers to answer this question 
 

[Zach Gomulka]

The CB update kit will make your Dells think that they are bigger then they actually are...

[Diederick/DVK]

Yeah, but i've heard negative things about that update kit as well...
Don't remember the exact complaint though.

[besserwisser]

Kawell did a test and 40 dells kept up with 48ida´s to 6500rpm. I would say they are okey to 150-160 hp depending on jetting. Carbs have no brain,they dont know what size your motor is. they just do what you set them up to do.

[Diederick/DVK]

well, i'm sure you know it better 
 

[Jordy/DVK]

Kawell did a test and 40 dells kept up with 48ida´s to 6500rpm. I would say they are okey to 150-160 hp depending on jetting. Carbs have no brain,they dont know what size your motor is. they just do what you set them up to do.

 6500 RPM's on what engine? A 1776 or a 2332?

 I mean 0,5*6500*1.776 = 5772 litres of air per minute... and  0,5*6500*2.332 = 7579 litres of air per minute...

 A 40 mm dellorto might not choke on a 1776cc @ 6500rpm but that's the same displacement of air as a 2332cc @ +- 5000rpm...
 

[Jon]

If you do a simple CFM calculation on 40 DRLA you get a optimistic total of 591 CFM. Thats 147.75 pr throttle.
To turn CFM into "real" horsepower this formula works for the VW flat four CFM x 0.27 x 4 cyl = max HP

So 147.75 x 0.27 x 4 = 159.57 hp  Besserwisser is right on the money.

Jordy, regarding how to get a engine capable of sucking 591 CFM, there are several ways as you know. Big capacity and low revs, or small capacity and high revs, its you choice.

For fun I calculated the IDA just to check out the max. 1024 CFM total  = 276.48 hp  This just seems sooo wrong, but according to the latest reports from Finland its possible?   

[Rasser]

If you do a simple CFM calculation on 40 DRLA you get a optimistic total of 591 CFM. Thats 147.75 pr throttle.
To turn CFM into "real" horsepower this formula works for the VW flat four CFM x 0.27 x 4 cyl = max HP

So 147.75 x 0.27 x 4 = 159.57 hp  Besserwisser is right on the money.

Jordy, regarding how to get a engine capable of sucking 591 CFM, there are several ways as you know. Big capacity and low revs, or small capacity and high revs, its you choice.

For fun I calculated the IDA just to check out the max. 1024 CFM total  = 276.48 hp  This just seems sooo wrong, but according to the latest reports from Finland its possible?   

How are venturis calculated in this calculation ?       

[Jon]

The program I use is a small part of Engine Analyzer pro. So I don't know how its done. The parameters I enter is what type carb "with booster venturi" or without, slider and one more I cant remember, then you add the throttle plate size and number of throttles.
Its just an loose estimate.

[Rasser]

The program I use is a small part of Engine Analyzer pro. So I don't know how its done. The parameters I enter is what type carb "with booster venturi" or without, slider and one more I cant remember, then you add the throttle plate size and number of throttles.
Its just an loose estimate.

did you do the calculations with "no booster venturi" selected ?

[Jon]

I did it "with"... is that wrong

[Rasser]

I did it "with"... is that wrong

Don´t think so.... I was just thinking that the restrictor of how much airflow you can get through a 40mm dell is the size of the venturi, and here we don´t know what size was used for the calculation.

[SMO]

Yes would be nice to know what kind of venturis the calc. is based on.

Sometime isn´t BIG things the best way. Small venturis get high air speed.

Have also read some where that dellorto 40mm flows like a 48 ida up to 6500 rpm.

If you use 2 Dellorto 40 on a V8 .. like a 4 barrel carb. you can put out alot of power.
Of course individual runner dosn´t have same capacity as witha 4 barrel carb.

So if you have a cam with small duration (max 6500 rpm) and high lift  i´ll think
you can put out alot of HP up to 6500 rpm with dual dellorto 40mm. Nice torque at low
rpm. a very nice stop light engine

Right now i´m building a 2332cc with Street eliminator heads and dual dellorto 40mm.
Think it will work pretty well. We will see.

[Rennsurfer]

Interesting thread and thanks for the info. I'm considering a 1776cc, Engle 125 cam, mildly ported heads, slightly larger valves than stock, and a pair of 40mm Dellorto carbs. Exhaust system is already @ 1 5/8", including the heater boxes.

Not the original 1915cc w/44 or 48mm carbs like I originally planned... but the smaller engine can be had for far less money. And based on what I've been reading about the Dellortos, I just may go this route, instead.

[Torben Alstrup]

I have used 40 dells w. 36 mm venturies on 2275´s They had some pretty wild lower rpm torque, but still reved to 6 grand without a problem. Power was limited to 154ish hp @ 5500 rpm.

T

[Speed-Randy]

Interesting thread and thanks for the info. I'm considering a 1776cc, Engle 125 cam, mildly ported heads, slightly larger valves than stock, and a pair of 40mm Dellorto carbs. Exhaust system is already @ 1 5/8", including the heater boxes.

Not the original 1915cc w/44 or 48mm carbs like I originally planned... but the smaller engine can be had for far less money. And based on what I've been reading about the Dellortos, I just may go this route, instead.

Uh Mark, 90.5's and 94 P/C are the same price, and for what amounts to about $100 more why wouldnt you buy a stroker crank and have some power? You could run a 78 crank with everything above, stock rods, and have around 120-140hp, depending on compression, as opposed to the 70 or so you'd get out oa a 1776, for only a $100 dollars more than a 69mm crank

[Rennsurfer]

Uh Mark, 90.5's and 94 P/C are the same price, and for what amounts to about $100 more why wouldnt you buy a stroker crank and have some power? You could run a 78 crank with everything above, stock rods, and have around 120-140hp, depending on compression, as opposed to the 70 or so you'd get out oa a 1776, for only a $100 dollars more than a 69mm crank

Uh, Randy... 'cause the case and heads that I'm being offered have already been cut for 90.5. That, and because the pistons and cylinders are being offered (brand new) by another person for a very reasonable price. I don't want a 78mm crank... only interested in running the 69mm counter-balanced crank & stock rods that I've had since 2008. I'm on a very tight budget, so there many reasons why I must plan this out a certain way.

Plus, I don't need a 12 second car, like everyone else strives for. I had just as much fun with my 1700cc engine, thirty years ago, and I'll have fun with this 1776cc.

Hope that helps answer your questions.

[Speed-Randy]

Uh mark that motor 78x90.5 could only make a 12 second street car if it was being towed by a 10 second car . Your general statement was 1776's are far less exspensive than a 1915, not, I already have these parts, so i'm gonna do this. Have Fun with it, if you need any other parts , I will be happy to help you out

[Rennsurfer]

Uh mark that motor 78x90.5 could only make a 12 second street car if it was being towed by a 10 second car . Your general statement was 1776's are far less exspensive than a 1915, not, I already have these parts, so i'm gonna do this. Have Fun with it, if you need any other parts , I will be happy to help you out

Thanks for the offer. I should have been more specific about already having certain engine components that are machined for 90.5mm. The main thing is/was, I've never had any experience with Dellorto carbs and never considered using them. But after some research, it turns out that they flow really well and have better access to their jets as opposed to the IDF units that I was going to get.

[wph]

You can push a pair of 40mm Dellortos with 36mm venturis up to 191hp/232Nm @ 6030rpm, done it. Engine combo 80mm stroke, 92mm bore.
Power fell down like a rock after 6000rpm, this was on a short tuned length manifold. With a longer manifold it would have dropped at lower rpm.   

[OveF]

40mm Dellortos making 223HP: http://forums.aircooledtechnology.com/showthread.php?t=3553

[Rennsurfer]

Thank you for the last two posts... I have a possible opportunity to get some 40 DRLA carbs. Hence why I was interested in this.

[Neil Davies]

Thank you for the last two posts... I have a possible opportunity to get some 40 DRLA carbs. Hence why I was interested in this.

Fred, in the words of the great philosopher Nike, "just do it."!

I've just put a pair of 40 dells on my 1600 as my 36's were seized. They're a far superior carb to the kadron, so if you get them and run them now, sell the kads on to fund more parts for the 1776, then just rejet for the bigger motor.

[Rennsurfer]

Fred, in the words of the great philosopher Nike, "just do it."!

I've just put a pair of 40 dells on my 1600 as my 36's were seized. They're a far superior carb to the kadron, so if you get them and run them now, sell the kads on to fund more parts for the 1776, then just rejet for the bigger motor.

Great! I'll get right on this. Wait... they DO make single port manifolds for Dells, yes?

 

Still have my original engine, Neil. So I'm trying to figure out which low dollar two barrel dual carb set up I can run with my bigger engine. Currently using Weber 34ICT carbs 'cause I gave up on locating single port Kadron manifolds. Funny... used to throw away many of those when I worked Auto Haus. Anyway, thanks for everyones' advice on these carbs... think I'm gonna do it.

[Neil Davies]

Fred, in the words of the great philosopher Nike, "just do it."!

I've just put a pair of 40 dells on my 1600 as my 36's were seized. They're a far superior carb to the kadron, so if you get them and run them now, sell the kads on to fund more parts for the 1776, then just rejet for the bigger motor.

Great! I'll get right on this. Wait... they DO make single port manifolds for Dells, yes?

 

Still have my original engine, Neil. So I'm trying to figure out which low dollar two barrel dual carb set up I can run with my bigger engine. Currently using Weber 34ICT carbs 'cause I gave up on locating single port Kadron manifolds. Funny... used to throw away many of those when I worked Auto Haus. Anyway, thanks for everyones' advice on these carbs... think I'm gonna do it.

Damn, forgot about that! Pesky single ports! You could just run one half of the dellorto like the formula vee guys do...

[Rennsurfer]

Damn, forgot about that! Pesky single ports! You could just run one half of the dellorto like the formula vee guys do...

HA! That's right... I forgot about those guys. They do some bizarre things to get their cars on the track & to properly pass inspection.