Dellorto DRLA 40 B. What jetting for a 2110cc Type 1 engine?

Despite having my carbs since 2004, last week I learnt more about them & discovered some of my jet sizes!

Having read lots of Dellorto threads on here saying 28 vents, I can guess at likely responses.

So knowledgeable Dellorto people I look forward to suggestions on what I should be running!
Not urgent, but I thought Id ask here, plus friends running big T1 engines, eurocarb and the rolling rd I've been to in the past.

The camper runs fine at the moment, although it is very thirsty for fuel: 20mpg best
Current Set Up is:
Vent: 32
Air Corrector: 175
Emulsion: 9164.2
Main Jets: 145

Idle: 55 (From notes in 2013, could be wrong or jet changed since)
Acc Pump: I don't know
Jets/ etc could have been drilled in the past, but no scratches have been made on them so assume all is as it says it is.


Possibly relevant info:
2110cc type one engine.
Twin Dellorto DRLA 40 B's (no vacuum take off). Made in Italy
Offset Manifolds
CB performance throttle linkage (Thoughts best kept in other threads)
Web 1 1 1 camshaft (spec available if required)
Cylinder Head Valve sizes: Intake 40mm X 35.5mm exhaust
Malapassi fuel pressure regulator & filter.
Points & 009
I rarely rev it over 4k revs
Been on a rolling rd at least twice, perhaps I've not asked them to check the right stuff, but no one ever suggested XorY jets would improve running/fuel economy .

Assuming I end up changing vents/jets etc
Is there an idle jet on a long stack that makes them easier to get at (or have i just imagined this)?

I've tagged people who have Dellorto's or I think may be interested (apologies if your not)
@Zed @77 Westy @F_Pantos @Deefer66 @Dicky @lhu1281 @snotty @areksilverfish @scrooge95 @docjohn @Dubs @mikedjames
@S1mon

Thanks for looking.

I've read these other threads and they may be useful to people in the future
This one has what jet sizes that some of you are running
https://thelatebay.com/index.php?threads/dellorto-drla-40-jetting-advice-needed.73116/#post-1357661

https://thelatebay.com/index.php?threads/dellorto-idle-jets.89581/

https://thelatebay.com/index.php?threads/dellorto-emulsion-tubes.91590/

https://thelatebay.com/index.php?threads/more-drla-40-nonsense.89412/

 

I wouldn't say 28 but 30 might be good. If you do, it's either back to the rolling road ot install AFR meter and DIY.
30/135 might be a good place to start.

 

Going to a rolling road sets you up for the standing quarter mile, you are drag racing using the mass of rollers instead of the car.
But what it doesnt do so well is a trundle along a flat road and then gently climb a hill at 40mph..
Start at the rolling road, but instead of paying twice, buy an AFR meter with the second tranche of cash.
You would then have a good starting point to tune "up a size, drive it , down a size, drive it, compare..."

 

Thanks that is very useful.

My carb knowledge has been gradually improving since the air filter stud down the carb incident!
Just been re reading your drla 40 nonsense thread, you have certainly dome some serious testing of different jetting options.
An AFR meter is also on the list at some point, as is a 123.
I'm telling myself that any vent/jet changes I do will pay for themselves in fuel savings!

No two buses/engines seem to be the same.

 

Yes very good points.

I went to the rolling rd after the engine was built and run in, as I was advised to by the engine builder, but also because i didn't really understand the carbs or have the confidence to fiddle with them myself.

I used to have an old school needle based AFR gauge, but it didn't show me anything useful. The digital ones i've looked at more recently look great, but are v expensive.
If funds were unlimited I would bite the bullet and get one now, but ive got quite a few potential camper expenses coming up so will have to see.

 

The 009 will be killing the fuel economy; there won’t be enough ignition advance in the cruise and you can’t add any because there would be too much advance at start-up and accelerating.

The Web 111 has a lot of lift, it should make good torque with 2110cc but it has an aggressive profile and will be very hard on the valvetrain – it needs a lot of spring pressure.

It’s not a bus spec engine and with 32 vents, a 009 and a Web 111 I’d be happy with 20mpg. 28 vents would be too small for the spec/capacity, going down to 30 vents might make tuning at low revs easier but it wouldn’t do much, if anything, for the economy and you’d lose top end power.

Quickest and easiest improvement would be to get rid of the 009 and fit a SVDA distributor, a 123 would be good but you really need a different cam.

In my opinion the vents and jets aren’t the problem, the distributor and cam are.

 

WOW…..is this the cam??

https://vwparts.aircooled.net/Web-Cam-Type-1-Camshaft-Grind-111-1-1-Rockers-p/00-602.htm

 

If it’s a Web 111 that’s the one. As I said, it’s not a bus cam. ‘This cam is "violent" on the valvetrain, don't expect more than around 5000 miles out of the valvetrain’

 

I suspect Paul made a typo, he's had the engine for many years.

 

Thanks very interesting info.
A 123 is on the list, perhaps that should be my top priority above jet changing etc. What a can of worms!

A different cam certainly isn't on the list as it would involve huge expense & pain.

However I'm now going to derail my own thread, as the cam thing is very interesting as I've just had some valve related issues.

Back in 2015 ...@Zed raised the aggressive profile of the cam being hard on the valve train point in the past. I think it was on aircooled.net.
I raised it with the engine builder who said:
I’ve never ever seen anything about these cams only lasting 5000 miles, I use them because of their quality and we’ve got many engine with a lot higher mileage than that with no issues. The valve spring pressures need to be correct, the running in procedure correct and the correct oil used at all times. So I can’t understand what your friend is on about. Well all I can say is that in our experience, we’ve not had any issues with it and have used it many, many times.

Then I asked WEB themselves who said:
Thanks for the info Paul. I will ask him about it since I have never seen this. He is right about the rocker ration 1.1 is the best but lasting 5000 miles seems odd.
When chased they said: So sorry I have not but strange he keeps offering them. He is right about the rocker arm ratio, only 1.1

Fast forward to Techenders June 21, my engine got diagnosed with no compression on number 2 cylinder, so got recovered home
Previously It had been driving fine especially when warm, but when i think back it had been a bit rougher for first 5-10 mins of a drive.
When the engine came out the cause was a loose intake valve seat. (I believe/guess when the engine was warm the valve seat dropped back into place and the engine was running on all 4, but obviously I'm really glad @mikedjames had diagnosed no compression and prevented further damage being caused).

After consultation the heads went off for repair where the VW specialist machine shop found that 7 out of 8 valve guides were loose!
Initial comment was that he sees this from all manufactures and that he thinks they were not fitted tight enough in the first place (no obvious sign of overheating on my heads). I got relevant measurements of holes and oversize valve guide size etc. So i still don't know what caused it, but again it makes the CAM question interesting.

Mofoco who manufactured the heads didn't reply to my enquiry and still haven't.

I knew the valve Spring pressures needed to be correct, so asked the engine builder before he went on holiday, he gave me a figure of 1.550" @ 150lbs.

When the machine shop came to do the spring pressures they struggled to find any springs that would deliver those figures.
Keen to get back on the road as quick as possible I asked other relevant people for their thoughts. Getting a straight answer/correct info was a nightmare.

Mofoco: didn't reply!
Web cam shaft said: really don’t have the best valve spring for the 111 profile. We offer a dual one that could do the job but I would rather you use the beehive spring that Joel sells. There company is Mohr Performance. He has used the 111 many times and has had great success with it.
Mohr Performance said: I don't have a number, but I use SCAT heavy singles with 2 .060 shims. We spin class 9 motors to 5500 without any issues.
Web cam then said: just make sure you they are good springs we like the PSI wire and beehive on that one. We do have a dual spring (not beehive) could be used it has 145# lbs at the seat installed at 1.500 and good to .520 valve lift.
Engine Builder got back from holiday. I asked where the spring pressure figures came from and he said he found them online!
A potential source of suitable springs was mentioned but neither the engine builder or machinist were prepared to speak to them.
I spoke to them and soon realised why no one wanted to deal with him!
In the end I gave up and left the machine shop & engine builder to talk to each other and work something out.
I ended up with chromoly caps & dual springs set at 1.550" @148.2lb. Lift .550" @312.8lb. Coil Bind @.670".
I have even less knowledge of valve springs than of carbs!

So if anyone is even reading after my ramblings, I still have no idea what caused my cylinder head / valve issues.
Was it the Mofoco valve guides being installed too loose in the first place?
Had the cylinder heads overheated causing an intake valve seat to become loose?
Is the WEB CAM 1 1 1 the culprit?

Will we ever know?
Does anybody even care, I don't after wasting my lunch time writing this *****!

I still love my and the engine though, so i'm off to give it a big kiss

 

Yes, there is an extended idle jet holder (Eurocarb will sell you some) that makes them easier to get at. Mixture screws with the hex head (instead of slotted) also useful.

As above, I’d get rid of the 009 as a start.

 

I often stroke my Type 1. They’re cuddly.

 

It's a 2.1L air cooled engine in a bus - 20mpg is really not so bad.

 

that's on a good day!

 

I know that feeling. Max I've ever had from mine was similar with the wind behind me. I try not to think about it!

 

Could still get a vac 123, just don’t connect the vacuum input.

 

Please explain how this would help in any way?
Actually, I bet a tuneable 123 could be set up for manifold vacuum.

 

Better HT, spark-balancing, tea-making and all the other good things.

@paulcalf Have a squint on your Dells where the vac takeoff should be. Possible everything’s in place, but the external orifice has been blanked off. Might be poss to mod one to provide a takeoff?

 

My original receipt says WEB III Camshaft. No idea if they are meant to be 1's or i's.
When i sent that aircooled.net stuff to my engine builder he didn't say that isn't the cam you have, he just said he'd had no issues with them.
WEB camshafts also said no issues.

I respect the opinion and thoughts of the many experts that we have on this forum.
I also respect the engine builder who has been building great engines since at least 1995 & quite a few of them.
When I bought my camper in 1997 it had one of his engines in it (smily face whilst driving)
At some point later I replaced it with a terrible off the shelf engine (sad face whilst driving it and not wanting to drive it much)
In 2012, before i joined the forum i got the original engine builder to build me this 2110cc (Very smily face returned).
I am open that i know very little about technical matters, I put my faith in a reputable engine builder whose engines i had already experienced.
A few issues along the way (not caused by him), but I'm still happy with my engine and still rate his engine building skills.


As said above @Zed first raised the 'violent' on the valve train thing years ago.
The engine builder and WEB reassured me all was fine with my CAM.
I should ask aircooled net what they are basing it on? I'll see what others with WEB 1 1 1 camshafts think/have experienced.

Should I be worried by people posting links to the aircooled.net article where they are still selling that CAM , but saying only expect 5000 miles from it?
Or trust the engine builder & cam manufacturer.

Will this engine keep going until electric/hydrogen engines are more reasonably priced?

Time will tell