Comparing IDF PowerBand to DRLA PowerBand, Misconceptions?

[RailBoy]

Just checked with CB Performance, no luck there....

Guess it maybe carb upsize time. Any ideas on Vent Peeps out there? That
is if it is feasable.

Engine really begins to run out of Breath around 5,200 rpms. RB
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[quote="smitty24"]"HELP, I ported my own heads and now have fire coming out my ass" .[/quote]

[esde]

[RailBoy]

Ok, been looking around for 36 vents for my 40 DRLA's, No Luck yet...

So in a previous post on the thread it is said that the IDF's are inferor to DRLA's.
Do I have this correct for Street Use? So the DRLA's have a few more HP as well? RB
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[quote="smitty24"]"HELP, I ported my own heads and now have fire coming out my ass" .[/quote]

[esde]

Like Modok said, there are many models of IDF, so making an accurate IDF to DRLA comparison is not easy. Somewhere here (just searched but didn't find it) he listed some of the models and variations. I recall reading there were differences in top bore/bottom bore/ stock venturi size, number of progression ports. So, just specifying a size might not get you an apples to apples comparison.

I replaces some weber 40's with the old style roller accelerator pump with freshly rebuilt dellorto 40's, and the owner couldn't tell the difference. But, he's also the sort of guy to drive a mile before realizing he has a flat tire. But they're at least close enough to fool someone thats not paying attention.
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modok wrote:
Bent cranks are silent but gather no moss. I mean, ah, something like that.

[RailBoy]

Thing is like I hit on previously. That there are the New Empi D's on the Mkt., plus there are some reputable people out there to get used DRLA's from. They just costs...

See what I heard and noticed on two cars is that the Webers had what I thought were spikes in there RPM Transioning. Meaning as you excellerated slowley, the DRLA's were steady while the IDF's had spikes and you had to inticipate that if you were driving technical roads... Basically saying the DRLA's are a "Safer" carb for Type 1's for Street Use for they do not "Crack In" as you throttled slowely were as the IDF's did some.. But one car was a New Single Carbed 2110 w/Redline Intake and the other was a 6 cylinder Porsche, so I really don't think these cars are a good bases for me to draw on for info other than that... RB
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[quote="smitty24"]"HELP, I ported my own heads and now have fire coming out my ass" .[/quote]

[modok]

Sorry I'm not saying much but I swear.....we already discussed this 2-3 years ago.
36 idf, 44idf, 48 idf, 40idf-78-83 web-orto, ALL the DRLA carbs, IMO they can ALL work GREAT on the right engine. As good as port fuel injection.
I don't like the weber 40 IDF-70 model as much, so I leave that off the list, but it's better than a solex The 40HPMX is improved, but not as good as he web-orto yet.

44idf and 48 idf has divorced idle circuit, these are better suited to more radical engines with radical cams and more radical heads, but if you get the combo right they will accelerate up from idle at any throttle position with no hiccups at all. By"right combo" I mean the heads with the right flow ratios, not overly large exhaust.
They aren't as suited to getting the best MPG or driving on snow/ice.....but if they are on a radical engine combo .....you would not be expecting them to be super good at that ANYWAY.

36mm vents could work, but look at the aux vents in the larger models of dellorto and think about how you could modify your full circle aux vents to flow more. The ID of the full circle ones is only about 38mm, not enough

[RailBoy]

Ok Modok with the analysis, you are saying if I have this right from memory that on a X & Y graph, the Linear Curve of the powerband is the same with them all if on a Vertical access is RPM and on the Horizontal Access of the graph is HP? So in fact they all perform the same? That is if my graph that I wish I could make and show right now... RB
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[quote="smitty24"]"HELP, I ported my own heads and now have fire coming out my ass" .[/quote]

[modok]

The carburetor does not make the powerband, it just sprays fuel.
If you use the right carburetor for the job, it will work very well. They are all very good at doing the job they were designed to do IMO.

How about this:
You can build the engine to match any carburetor.

BUT.
You can't build a carburetor to match all engines.
If the engine combo is screwy then you could try every carburetor and its not going to fix the problem.

[veeweeman]

[vwracerdave]

Alfa1750 on eBay can get your 36mm DRLA venturies and whatever else you need. http://stores.ebay.com/ALFA1750S-CARBURETORS-PARTS-STORE?_trksid=p2047675.l2563
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2017 Street Comp Champion - Thunder Valley Raceway Park - Noble, OK
2010 Sportsman ET Champion - Mid-America Dragway - Arkansas City, KS
1997 Sportsman ET Champion - Thunder Valley Raceway Park - Noble ,OK

[RailBoy]

Hey RacerDave, do you think that 36 Vents are within operational limits of 40 DRLA's? Meaning that there will be no negative effects, air turbalance, fuel atomization issues? RB
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[quote="smitty24"]"HELP, I ported my own heads and now have fire coming out my ass" .[/quote]

[vwracerdave]

No I don't. You will spend $200 on vents and jets and shipping but you won't get your moneys worth with the rest of your engine combo. They will work and the engine will run, but since you have a 5000 RPM limit on your engine larger vents will only help the top end. It will not help in the 2000-3500 RPM range where you do all your street driving.

My best suggestion is to not spend a nickel on your current engine and build the new engine you were talking about. With what you have now you will always have to compromise on something.
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2017 Street Comp Champion - Thunder Valley Raceway Park - Noble, OK
2010 Sportsman ET Champion - Mid-America Dragway - Arkansas City, KS
1997 Sportsman ET Champion - Thunder Valley Raceway Park - Noble ,OK

[Danwvw]

[SamT]

I’m a dellorto man, but now That the empi carbs are having success it makes it real hard to justify taking a chance on some old dells. I bought the 48’s that I run for $600 about 11 years ago. (Before empi has 48’s). It cost me $600 to have them made like new at ACE not long after I bought them.
I have some 45’s I got on eBay for $280 that run like brand new though.

I’ve always felt like dells are more forgiving about jetting. The biggest issue I’ve had with both is buying sets offline that show up worm out.
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Rides:
300HP 900lb turbo VW rail 18/15 travel
Never ending jeep/rzr hybrid build!
http://www.thesamba.com/vw/forum/viewtopic.php?t=546712

[madmike]

RB what size header u running? What goes in MUST come out
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'Black Ice'Drag Buggy 'Turbo'
Rail Buggy 1915 turbo
76 Drag/Street bug 2180cc 'Turbo' 11:85 @113 mph"If I go any faster I'll burn up the Hamster" ,gets 28 mpg. also 10/09/22 11.90 @115 mph
"If I'm ever on Life Support,UNPLUG Me, Then Plug me back In see if that Works"

[RailBoy]

I started off with a mosh of items from a $1,200 Engine...

I am running a 1 3/4" Berg Header w/Heat. Heads are CB Street Eliminators w/ 42mm x 37.5mm Valves, also currently I have 1to1 Ratio Rockers in it. Heads are ported and intakes are matched ported.

But yea, the engine is coming out and maybe cracking it open to re-balance it. Not sure yet, only time you can tell it needs balancing is over 5,400 RPMs, which is suitable for street use.

Yea, I am not 100% sure I can re-balance it do to availability of my VW Mechanic friend's time for he has a 40 hour a week job as well and people waiting for him to help them out as well. I am pulling my engine for trans work.

Oh, currently running a Engie 120 Cam... Yep, a mosh,lol.. RB
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[quote="smitty24"]"HELP, I ported my own heads and now have fire coming out my ass" .[/quote]

[Cptn. Calzone]

If the motor was balanced when you nassembled it...how did it get un balanced?As in it didnt loose or gain weight...which is waht balancing is all about
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71 westfalia
67 912 Porsche Quintilla
67 Single Cab aka my work horse

[RailBoy]

Yea no doubt, we were in a rush to get it done at lowest cost at the time. Everything was thought to be within reason, which it is until 5,400RPMs..

But now since the trans is coming out, the case may get split if there is time for the builder, another guy. Both have good repuations though, the crank was thought to have been balanced in the other engine.. But new pressure plate, disk, and flywheel were added. So, there the theory goes that it was within reason, guess that went out the door though with the flywheel and all..

But like RacerDave said it is a great street engine and runs solid and smooth up to 5,000 RPMs. Throttle is Super responsive. Thing is when you want to wine it up it simply can't do it. Breathing wise nor Balancing wise, thus really it just has a Max RPM of 5,000 RPMs, so that is how I drive it with in that limitation... RB
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[quote="smitty24"]"HELP, I ported my own heads and now have fire coming out my ass" .[/quote]

[mark tucker]

[RailBoy]

Yea, Mark hit on a good note about tuning and drivabilty when carbed. I have heard smaller carbs are good for low end grunt if tuned right.

My car runs like a top off idle-5,000 RPMs. Has crisp throttle responce through out that intire RPM range. Also, I average 24 mpg in the moutains on highways and back roads, though when tuning I got 13 mph once,lol, but that is another story of just being on it in the mountainous backroads. But on flat highways for I take those as well, I average 28 mpg. This is averaging around 65mph.

What is a coiencidence is that my engine starts to run out of breath around 5,400 RPMs when the balancing becomes an issue, so as long as I am below 5,000 rpms or so the car runs great and performs great.

So yea, we will see about rebalancing the engine, up to the builder and if he has a slot to make it happen??? Then I will be looking for carbs for sure, but will be in no rush for the engine is tuned for lower rpms for time being.. RB
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[quote="smitty24"]"HELP, I ported my own heads and now have fire coming out my ass" .[/quote]