The Cal-look Lounge

C'mon guys care to share ?  :D I have been wondering on and off for a long time now who has achieved NA power figures in excess of 200 bhp at the flywheel with a set of Dellortos......??? I have always heard stories that Dellorto's ( DRLA ) will never match Weber IDA for HiPo naturally aspirated motors ( ie,no power adders such as NOS/Blown/Turbo etc ).I realise IDA's have always been the racers favorite but then I was also told you couldn't reach the magic 100 mph over the quarter with DRLA's and you couldn't make 200 bhp either etc.DRLA's are street carbs that can be used for street and strip whereas IDA' are pure race.

Well I'll start the ball rolling with my old 2276 T1,that made 201 bhp with 48 DRLA's and ran consistent 12.7 / 12.8 with a pb of 12.5@106 mph.No slicks.This motor ran FK89 and Street Eliminators 44 x 37 with CR at 10.8:1 if memory serves and fuelled with 98 Octane Shell Optimax,UK blend.

Has anyone done something similar with Dellorto's ? maybe made 210,220,230 bhp+ ???

Be real interested to find out and maybe bury some of those myths  ;)

  He's not on here I don't think but Jason Young has.  Sorry I don't think I've got pics of his car but it's street driven at times and has done low 11's.  Lot's of work on his carbs by he and Doug Berg.

James Beahm made 210 fwhp with a 2332 with CB wedgeports, 5.325 rods, FK-45, 1 5/8" exhaust and 48 Dells on pump gas with the belt and muffler. It made 201hp at the at the engine build off below.

http://www.cbperformance.com/Feb2007c.asp

I did in the late '90s.

http://www.youtube.com/watch?v=mUJI-PrZDc8&feature=youtube_gdata_player

Jason's '64
80x94 48 dell's and pump gas.

My 2007cc motor ran 12.50's at 105ish mph, admittedly in my race car (1640lbs with me in it). I can't remember if they're Weber IDFs or Dell'Orto DRLAs, it's been so long since I've seen them, but they are definately 48's, and certainly aren't IDAs... I'd gues it has about 160bhp but it did over 100mph!

This is a great start guys  :) and some good results.Another story I have heard when assembling a HiPo motor are that Dells will be the limiting factor in terms of making the higher bhp.I wonder in reality just how "limiting were talking here ? has anyone published back to back tests using unmoded 48 Dells versus unmoded 48 IDA's on a typical 2liter plus engine you read about all the time in street and strip write up's, say 2276 / 2332 with FK87 / 89 and 044's or SE's with 44 x 37 valve and say 10.5 / 11:1 CR.

So far my experience of DRLA versus IDA on a street driven bug still favours DRLA for smoothness,good transistion from idle through mid range and onto main and generally much better behaved on the street ( user friendly ).It is interesting to see you guys are making power over the 200 mark.

My current 2332 motor is making 228 bhp at the flywheel on 51 IDA's but I am not that happy with the way it drives on the street and wonder whether I could have achieved say within 5 bhp staying with 48 DRLA's ?  It's hard to know where to put the Dells down and make the switch to IDA staying with carbs as I haven't been able to find any published material that gives a good guideline.

Some guys speculate and comment that 51's are an overkill unless your making 240-250 bhp at the flywheel and that 48 IDA's are still good for up to say 240 ?

Any thoughts from experience gained out there in the real world rather than bench racing ??  :D

Cheapest and fastest approach would be to tune your current set up.

Why are you not happy?

A stock  48 IDA with Weber stacks and real Weber vents can make over 240hp. One big limit to the DRLA is fuel supply.  Its hard to get enough in and the float bowl is too small.

Hey Beetle Bug.I am happy with the power output as I was expecting 225-230 bhp at flywheel.The motor has been extensively tuned on a Stuska type Dyno to yield maximum all out power for drag racing so I know there is a trade off with street driveability.I am just noticing the 51 IDA doesn't behave as well as my old DRLA's did on the street.They were always tuned for maximum bhp for drag racing but yet were smooth as you like on the street too from idle up this was running 42 venturi.My current 51's started with 46 venturi and now have 44 venturi but that hasn't really made any difference to the feel on the street so far.I have more road testing to do yet as it's early days but it just struck me the difference driving on the street with the IDA carb.Maybe this is just what IDA's are like and I have to get used to and adjust my driving style accordingly........... ;)

Hey Taylor,that is indeed interesting about the capability of 48IDA's and now I can see why I have recieved comments that using 51's in my application is overkill in terms of size of carb.Also interesting comment about the DRLA,this is something I don't recall hearing before...... ;)

for what it is worth i run 48 dells (trijets) on a 2276 engine with an fk8 and 42x37 heads (non-welded) i think the power is for now in the 155 - 165 region. so nowhere close to what you expect or want, but i do can comment on their drivebility, and that iis great. they run so smooth once tuned properly. they seem to be an excellent carb that is for sure.
the only thing that could cause a limiting factor is the inlet or carbbody. the butterflies are 45mm and not 48. the venturies are therefore limited to 44 as to IDA's that have bigger butterflies, inlet,... so that could explain some of the lesser poweroutput in higher HP engines.
but i'd like to see some prove too of either they are that great or just not up to be an IDA.

Hello Shane,

I have no problem with my 51.3's very smooth I can't notice any difference from the 48's with smaller vents. However I've taken the time to tune the idle whilst keeping the all out power on the main circuit.

Regards

Paul

Hey Paul

Hope things are progressing nicely with your new / revamped motor and hope to catch up track side with you in 2012  :)

That's good to hear you have tuned your 51's to be real smooth.That's what I'm after for sure as like just like you my cars get driven on the street,to the track,raced and home again  ;) We'll have to have a chat and maybe you can give me some tips on how to tune these for road as well as race.

For what it is worth I just went out to the garage and measured one of my 48 dells and the butterfly is in fact 48mm, I believe you may have been mistaken above.

If his butterflies measure 45mm, then they are 45 DRLAs.

One big difference is the ID at the top of the carb.  An IDA is much bigger at the top.  Then, as mentioned above, you can put bigger vents in an IDA.

Fuel-delivery problems? Grandpa solved that in the early '50s by sumping the carburetors to run alky on the lakes. Think it's tough at a quarter mile at a time? Try three miles at flat-out.

This is the fuel-delivery system on Tom Beatty's bellytank (the first guy/car to go 160 FWIW). Beatty sold the car in '66 or so and died in '67 so this setup hasn't even been disassembled since at least then (the design dates probably to the '50s).

(http://i189.photobucket.com/albums/z23/hotrodsurplus/Forum%20photos/beattycarbs.jpg)

The red hoses feed the bowls through the main-jet wells. Inside each carburetor is a tube. That tube's open end determines the fuel level in the carburetor (same idea as float level). The black hoses connect to those tubes to scavenge the unused fuel and push it back to the tank.

Like a dual-sump oiling system this needs two pumps: one to feed and another to scavenge. Garlits, the Chrisman bros, and numerous others did the same thing in the '50s. In an early '70s HVWs there's a story about an off-road racer who did the same (might've been a Gil George idea). I think there's even a story on how to sump Kaduds sometime in the late '70s. There's nothing saying a similar system couldn't be implemented on a Weber/Dell/whatever.

And you'd be the friggin' mack if you showed up to a run with a pair of sumped carburetors. And you'd never run another bowl dry...ever.

That's a really cool idea! Thanks for sharing!

yep, it could be true and i have to recheck it to be sure not to be mistaken, but from memory that is what i measured. the strange thing is that there are the trijet tubes on these and i can't find any info on 45 trijets... so this is somehow a question i have been asking myself for some time and i hope to clear it up a bit. could you post some pics of your carbs please, for comparison?

Maybe that's a stupid question, but: why do the bowls run dry? Is that because the needle valve is to small? Why not to enlarge it?

Not a stupid question at all. You answered your own question in fact: if the needles are too small for the engine's needs the fuel level will drop. They usually don't run dry. But even small fuel-level variances influence the fuel mixture.

Enlarging the needles and seats is not as easy as it sounds. The fitting is often too small to enlarge. Even if it could be enlarged you would have to find a needle that had the same length as the existing needle as to fit the float tang yet was larger diameter to fit in the modified fitting. The fuel passes between the needle and the seat so the increase in size would have to be somewhat dramatic to make a large difference in the fuel flow.

My 2,7l typ 4 was dynoed at 225hp back in the days with 48 dells. :)

Cool  :) It's good to hear some of you guys out there have gone quite a bit over the 200 bhp benchmark with 48 Dells.I wonder who has pushed the horsepower the furthest without drastic mods to their Dells,ie any combination of jet and emulsion tube changes and stock off the shelf or custom machined venturi...???  ;)

From the feedback so far it certainly seems to indicate there is a lot of myth and hearsay that has been floating around for years saying you need IDA's to make in excess of 200 bhp at the flywheel and some of you guys out there have proved Dells can take you there and beyond.

2666 cc type 4. Web 86C cam. 48/40 valves. 11-1 CR. 48 Dells w hand taylored stacks, 1 3/4" header. 223 hp on the street. BTW the strongest allround engine I´ve ever built.
T

Good Numbers indeed Torben  :)

I wonder if anybody has built smaller 2 liter motors either T1 or T4 and come close to or exceeded the 220 bhp mark with 48 Dells then ? say 2.1 /2.2/2.3 ???

Didn't Raby do over 200 on a type 4 with DRLA 45s?

Yes. Raby pulled 200 and change with 45´s on a 2316 with a radical cam. But still usable.

A customer of mine from Germany built a 2332 more drag than street engine  5 - 6 years ago. I am not fully aware of the specs. So Ii wohnt post much details. I know it was a FK89 cam, reworked Elliminator 2000 heads (from Heads up) He pulled 217 hp with a set of 48 Trijet with TWM or Jenvey stacks. I forgot which brand he got.
He later swopped to an all race set up with IDA´s $ stinger and close ratio transmission. Picked up 6/10´s on the quarter. I dont know what it converts to in power as I dont know the weight or ratios of his car.

T

i got it all backwards. sorry.
i took of a carb yesterday and indeed the butterflies are 48, but i confused myself because there is a step just above the butterflies which narrows the carb-shaft to 45mm and that step holds the venturi directly above it. so there is a limitation in the maximum size that the venturi can be.

I found the same

For reference my fairly mild 2276 with 45mm Dellortos made 151 whp and 171wtq today on the rollers. I was pleased with that.

Hi all ,
my previous engine was a 2332cc /86C/48 trijets (42mm vents) ,made 205hp@5600rpm and 27daNm @ 5100rpm with a broken inner  spring on the dyno session

That´s roughly 176 - 180 hp on the flywheel. most likely brings a smile on your face  ;D
T

Close but not 200hp: 45 dells with 37mm venturies - 189hp/252nm @ 6175rpm. 2274 - 044 44x38 - 10.4:1 - w130 - 1.25 - phoenix exhaust with stinger - msd 6al.

Although I'm pretty sure that the 45's are all that your engine needs, it would be interesting to see how the 48 Dells would change the powerband.

Just in case someone wants to try....
http://www.thesamba.com/vw/classifieds/detail.php?id=1213817

 Back in the late 80's I ran 48 Dells.  I talked to Gene Berg back then when he was testing Dells , fixed fuel delivery problems by removing screen from inlet, opened delivery hole up to needle and seat and upped the needle and seat size up to a 4.5 unit from Berg . When I found a set of IDA's cheap I made the switch.  Mike McCarthy