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Thu May 15, 2025 10:16 am

Hello,

I'm running an 1835 with Engle 100, 35.5mm intake, 32mm exhaust, solid rockers with stock ration.

The purpose is more everyday use than "hot rod". I've ran 34ICTs, 40 and 44IDFs on previous builds of different sizes.

Can you share your experiences running either 34 ICTs or 40IDFs on an 1835, taking into a consideration a balance between fuel economy, power, and durability?

Thanks for your input in advance.

Thu May 15, 2025 10:32 am

I put 40mm idfs on a friends 1776 after he had 34 ict carbs. Big difference. Runs better, sounds better

Thu May 15, 2025 11:47 am

Years ago I went from kadrons to 40 IDFs and never looked back. Superior in every way.

Sounds like a perfect engine for 40 IDFs

Thu May 15, 2025 12:13 pm

Dual 40 idfs.

I had dual dellorto 36 dlra on a 1600 and it ran great.

Thu May 15, 2025 12:21 pm

If a given set is on the shelf already I´d be inclined to use them. Dual carbs can generally run nicer and provide better power. BUT, its half the truth.
The first problem is that if you want to run dual sgl barrel carbs, DO NOT overcam the engine.
Second problem is that most ICT sets especially, come with terrible manifolds. CB has better manifolds (type 1) but they are by no means perfect,they need work to be nice. More or less the same goes for Kadron manifolds. Improve that and they can perform very well in their respected power window.

If you need to go buy a new set anyway, Dual IDF´s are hard to beat. just remember, they all come with their own set of problems.

Fri May 16, 2025 8:17 am

Alstrup wrote: If a given set is on the shelf already I´d be inclined to use them. Dual carbs can generally run nicer and provide better power. BUT, its half the truth.
The first problem is that if you want to run dual sgl barrel carbs, DO NOT overcam the engine.
Second problem is that most ICT sets especially, come with terrible manifolds.

Do tell. Same problem as a single carb combined with a cam with a lot of duration.

I picked up a tote full of carbs, literally 40 liters of carburetors. I got a couple progressives to add to my mounting pile of progressives. I got two sets of ICTs. I'm pretty excited about the ICTs.

I've had a few sets of Kadrons for years now.

So how much cam is too much cam?

How about:

69mm x 85.5mm, non- counterweighted, lightened flywheel because that's what the Formula Vee guys do... 9,0:1 compression, Panchito heads, Engle FK42, 34ICTs?

I'm guessing that's not not too much cam.

I'm still tryin' to figure out hot single port cams.

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Fri May 16, 2025 8:36 am

Dusty1 wrote: Alstrup wrote: If a given set is on the shelf already I´d be inclined to use them. Dual carbs can generally run nicer and provide better power. BUT, its half the truth.
The first problem is that if you want to run dual sgl barrel carbs, DO NOT overcam the engine.
Second problem is that most ICT sets especially, come with terrible manifolds.

Do tell. Same problem as a single carb combined with a cam with a lot of duration.

I picked up a tote full of carbs, literally 40 liters of carburetors. I got a couple progressives to add to my mounting pile of progressives. I got two sets of ICTs. I'm pretty excited about the ICTs.

I've had a few sets of Kadrons for years now.

So how much cam is too much cam?

How about:

69mm x 85.5mm, non- counterweighted, lightened flywheel because that's what the Formula Vee guys do... 9,0:1 compression, Panchito heads, Engle FK42, 34ICTs?

I'm guessing that's not not too much cam.

I'm still tryin' to figure out hot single port cams.
.

The ICT's are gonna make the panchitos a waste. I don't know if an ICT could even keep up with a well done 35mm port. Maybe with only 1600cc.

If you are stuck on single barrels, at least used Kads. They have WAY more potential than ICT's. The FK42 might be interesting if the heads are good.

For single ports, I think the duration needs to stay under 238deg, and a split cam would be ideal. I really like the cb2232. It would be really great to get that cam with a split exhaust with 4deg less duration.

Fri May 16, 2025 10:37 am

I know plenty of folks love kads...and ict's , but i have found tuning idf's to be more straight forward and easier than trying to get icts to work right. and , i spent 15 years dicking around with ICT's ..... i will take idf's any day, even on a stock 1600

Fri May 16, 2025 11:21 am

Brian_e wrote: Dusty1 wrote:
How about:

69mm x 85.5mm, non- counterweighted, lightened flywheel because that's what the Formula Vee guys do... 9,0:1 compression, Panchito heads, Engle FK42, 34ICTs?

I'm guessing that's not not too much cam.

I'm still tryin' to figure out hot single port cams.
.

The ICT's are gonna make the panchitos a waste. I don't know if an ICT could even keep up with a well done 35mm port. Maybe with only 1600cc.

If you are stuck on single barrels, at least used Kads. They have WAY more potential than ICT's. The FK42 might be interesting if the heads are good.

For single ports, I think the duration needs to stay under 238deg, and a split cam would be ideal. I really like the cb2232. It would be really great to get that cam with a split exhaust with 4deg less duration.

THANKS! You mean 238deg @ .050, correct?

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Fri May 16, 2025 12:50 pm

Dusty1 wrote:
THANKS! You mean 238deg @ .050, correct?.
.

Yes. The same "rule" more or less covers the dual ports engines. Here the classic W100 aint bad at all. In a well designed set up (and it does not have to be expensive, just sensible parts put together) ICT´s on decent manifolds can support up to about 100 hp, STILL with nice cold start and idle behavior.
Its sort of the same thing with Kadrons, only they will support more power if done right.
If you go into designing a cam especially for dual sgl carbs it is possible to go even further. I have used FK42/41 cams on 110 LC advanced 3 degrees in larger Kadron fed engines. Good overall behavior, decent idle at 950 rpm and 125 hp on a 2054 cc displacement.
Then there is of course my "challenger" 2165 from now 12-13 years ago, with 138 hp through a set of 40 Kadrons and "only" a Web 218/119 cam. That took a bit of work, but it was a fun project.
As always with esppecially dual sgl barrel induction, ignition and ignition timing plays a significant role in making it usable and nice to drive.

Fri May 16, 2025 8:46 pm

ICTs and 40idf-70 are......carburetors

kadrons and DRLAs are better performing carburetors.

ICTs work well for trikes and buggies

40IDF-70s are......the worst and most common IR carbs.
I'd rather they never existed, BUT, they are still "IR carbs" and IR carbs are awesome, so, I guess they are better than a poke in the eye.
The worst IDF is still better than the best solex, some might say.
I don't say that, but it's plausible, depending on taste

Sat May 17, 2025 6:38 am

modok wrote:
The worst IDF is still better than the best solex, some might say.
I don't say that, but it's plausible, depending on taste

Better than 40P11s?

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Sat May 17, 2025 12:59 pm

I don't know, probably
Italian design.... often does have a certain elegance and straightforward design.

Making elegant things actually work.....appeals to me,
rather than trying to improve the appearance of some convoluted ugly thing that does work.

Sat May 17, 2025 6:18 pm

Brian_e wrote: …..
For single ports, I think the duration needs to stay under 238deg, ….

I’d say thats a good ballpark if you want it to idle decent. I’d built an 1835 SP single center carb with a 2292 cam that had 272 @ .050, was mainly going to be a show engine and wanted something lopey. Problem was it wouldnt idle below 1200 rpm, figured it was too much overlap for a short / shared intake port and had bad reversion at low rpms. Swapped cam to a C35 with 246 @ 050 and all was good

Mon May 19, 2025 3:07 pm

Thank you all for the feedback and information. I think I'm leaning towards the IDFs.

Wed May 21, 2025 5:14 pm

Alstrup wrote:
Second problem is that most ICT sets especially, come with terrible manifolds. CB has better manifolds (type 1) but they are by no means perfect,they need work to be nice. More or less the same goes for Kadron manifolds. Improve that and they can perform very well in their respected power window.

Can I ask what type of work? Are there write-ups anywhere? I tried searching.