Anyone know these parts for a performance build? Opinions

[MykeNytemare]

I can't remember how (likely a facebook spider group post earlier this year), but I came into contact with a fella who sells Fiat parts from outside the US named Arturo. He send me some pics of some of the parts he has and, as I want to build a high output engine in the future, I was thinking about purchasing some stuff. I plan to run dual IDF44s and am hoping to reach 175hp or so in an engine that's streetable even if I need gas additive and premium.

However I do not know alot about these twin cam engines and also am wary of getting parts (especially cams which many member here say can be junk) without others verifying that they seem proper or maybe that they even have them on their engines.

I have attached phots of the specs he gave me for the cams and high dome pistons as well as pulley sets and adjustable 1" cam sprockets. I know AR, Vicks, and MidwestBayless sell some of these (or versions of them), but I really want to make the engine as nice as possible with all the "trick" parts I can find.

Anyone have insight to share? Thanks in Advance!

[SteinOnkel]

Yikes, I would not want to run those camelback pistons in the states. Our pump gas is not that great, especially in California. My other love has 11.5:1 cr stock and I need to retard the hell out of my ignition on that car (stock advance is something like 40 degrees, my timing map taps out at 31). It also has a knock sensor to save the engine if someone accidentally fills it with 87.

You will have none of those safety nets (or the adjustability and flexibility) on your setup. I would not want to rely on octane boosters constantly. Even the best ones do weird things like leave an orange ring around your spark plugs etc. And every time I get back from a track day I flirt with this idea. Sidebar: at the track I fill it with 100 octane and add 5* to my timing map across the board - the increase in torque is noticeable, no doubt about that.

Plus which, you'll get all the headaches of having to adjust these carburettors that are from the stone age. They can do only one thing: run too rich. Couple that with a rotating distributor, high compression pistons and sharp cams...oh boy. You'll be chasing your tail adjusting this thing for months and if you forget the octane booster just once and give it the spurs, that's the end of a very expensive engine.

I'd get all the hardware, minus the carbs and toss the rotating dizzy. For the price of those carbs you can get a nice programmable ecu (megasquirt is okay, but I'd recommend a nicer one like emu), go get a beefy throttle body, the proper triggers and run a nice wasted spark ignition system. Take it to a reputable tuner with the gas you plan to run (i.e premium pump gas) and he'll set up the knock threshold and timing maps for you. Or do it yourself.

That way you'll have a reliable car, that starts no matter the ambient temp and consistently puts out the desired 175hp while also getting proper mileage. My VW puts out 140hp to the wheels (stock is 125 at the crank) and gets 41mpg highway/36mpg city. No way no how is a carburetor setup anywhere close. Believe me, I've been there.

Cheers
Steiny

P.S: If you absolutely must run carburetors, look into motorcycle carbs. The research and development on those did not stop in 1975 and they are hand over fist better than IDFs. They're also dirt cheap. You can get a rack for $50-$100 on ebay and they usually have something like <15k miles on them.

[MattVAS]

I would just like to slip in that you may want to lower your expectations.
175HP isn't really going to happen.

If you want that level of power you're also talking about a completely different transmission and rear end. These 2 additional swaps are going to run up the costs by A LOT!

IDFs + adjustable cam gears + performance cam shafts + domed pistons = a good amount of power (certainly more than stock)

PFI + adjustable cam gears + performance cams shafts + domed pistons = a good amount of power (and more than the IDFs will get BUT it will cost FAR FAR MORE $$$!)

We've sold 8mm domed pistons for over 20 years here at VAS. They have gone into cars in every state in the US and into cars in dozens of other countries. They run fine everywhere just set your timing correctly. And if you can't get 93 octane fuel remember that using a different temp spark plugs can also reduce knock due to higher compression with lower octane.

By miles the 8mm domed pistons is the #1 piston that we have ever sold here. They run amazing and give GREAT torque. We built a customers engine years back with them. It was a 2.0 carb build and we were burning the tires off shifting into third with both my overweight butt in the seat & my brothers overweight butt in the other seat. His build was 8mm piston + 32/36 carb + 1.8 intake + our exhaust. And this car did NOT knock due to the pistons.

[MykeNytemare]

posted quoted replies so hopefully this keeps the conversation going a little

[MykeNytemare]

I would just like to slip in that you may want to lower your expectations.
175HP isn't really going to happen.

If you want that level of power you're also talking about a completely different transmission and rear end. These 2 additional swaps are going to run up the costs by A LOT!

IDFs + adjustable cam gears + performance cam shafts + domed pistons = a good amount of power (certainly more than stock)

PFI + adjustable cam gears + performance cams shafts + domed pistons = a good amount of power (and more than the IDFs will get BUT it will cost FAR FAR MORE $$$!)

We've sold 8mm domed pistons for over 20 years here at VAS. They have gone into cars in every state in the US and into cars in dozens of other countries. They run fine everywhere just set your timing correctly. And if you can't get 93 octane fuel remember that using a different temp spark plugs can also reduce knock due to higher compression with lower octane.

By miles the 8mm domed pistons is the #1 piston that we have ever sold here. They run amazing and give GREAT torque. We built a customers engine years back with them. It was a 2.0 carb build and we were burning the tires off shifting into third with both my overweight butt in the seat & my brothers overweight butt in the other seat. His build was 8mm piston + 32/36 carb + 1.8 intake + our exhaust. And this car did NOT knock due to the pistons.

I definitely want more info on your inputs as this car and engine are a new area for me!

Matt... I'm totally going to do a 131/132 transmission (eventually) and my rear needs an overhaul anyway. I'm not opposed to putting a few grand extra into that as I want to make this car reliable and have it last so my 7 year old can learn to drive it in 8 years! Also others said 175hp wasn't a crazy number if I ported the intake manifold and did some head work...do you feel that's not the case? I realize I may put $20K into this car eventually over the next few years but I am ok with that as it still puts me under buying a reliable sports car that can still carry my wife and 2 kids.

[MykeNytemare]

Yikes, I would not want to run those camelback pistons in the states. Our pump gas is not that great, especially in California. My other love has 11.5:1 cr stock and I need to retard the hell out of my ignition on that car (stock advance is something like 40 degrees, my timing map taps out at 31). It also has a knock sensor to save the engine if someone accidentally fills it with 87.

You will have none of those safety nets (or the adjustability and flexibility) on your setup. I would not want to rely on octane boosters constantly. Even the best ones do weird things like leave an orange ring around your spark plugs etc. And every time I get back from a track day I flirt with this idea. Sidebar: at the track I fill it with 100 octane and add 5* to my timing map across the board - the increase in torque is noticeable, no doubt about that.

Plus which, you'll get all the headaches of having to adjust these carburettors that are from the stone age. They can do only one thing: run too rich. Couple that with a rotating distributor, high compression pistons and sharp cams...oh boy. You'll be chasing your tail adjusting this thing for months and if you forget the octane booster just once and give it the spurs, that's the end of a very expensive engine.

P.S: If you absolutely must run carburetors, look into motorcycle carbs. The research and development on those did not stop in 1975 and they are hand over fist better than IDFs. They're also dirt cheap. You can get a rack for $50-$100 on ebay and they usually have something like <15k miles on them.

Steiny, I'd be open to running motorcycle carbs but don't want to run FI and such. I'd have to find someone to fab an intake. Also, any recommendations other than custom linkage and maybe FCR flat slide CV carbs like https://rover.ebay.com/rover/0/0/0?mpre ... 3813909245 ? I've had a 77 Kawasaki, a 86 Honda and an 11 Yamaha and each carb was pretty much the same as all were constant velocity...is that why you suggest them over IDFs? Advice?
Also, Should I be concerned that a normal distributor will fail? I've had very powerful Chrysler 440s and Chevy 454s that still ran distributors (with external coils or hei) but you think that needs to be gone on a high output twin cam build. Please tell me why as I'm curious as I learn about these engines.

[SteinOnkel]

Hello,

it all comes down to control. The more precisely you can supply the perfect amount of fuel and air for a given load/rpm situation and the ignite it at just the right time, the more power your engine will produce. This is why FI beats carbs every single time.

And it's also why Wasted Spark or better yet Coil on Plug beats distributors every time. I'm not saying a distributor will fail, that is highly unlikely. I'm saying that you will not reach your 175hp target with one. Nor will you have any sort of tunability. Sure, back in the day someone somewhere in a shed was able to change the weights in a distributor, but those days are long gone. You could run a rotating dizzy and something like the CB Performance Blackbox. I plucked around with that in combination to bike carbs for a while. It's a capable combination.

For intake manifolds, my got to shop is www.danstengineering.co.uk

Yes, CV carbs are much better at supplying the ideal air/fuel mixture than IDFs, DCOEs etc etc. You have the talented Japanese engineers to thank for that.

Bike carbs come with their own set of drawbacks, however. You need to build your own linkage (easier than it sounds) and as far as jetting is concerned...who knows! You'll just have to try what works.

I'll be doing it to my car Fiat later this year. Or not, depending on how well my Weber 34ADF performs.

Cheers
Steiny

[MattVAS]

I will upset a lot of people by saying this but head work isn't going to get you 175HP.
This number usually comes from people guessing based on a rear wheel HP dyno number. I've seen people do this all the time. They'll get 120-140HP on a dyno (which only gives rear wheel HP) and then calculate back in the parasitic loss to get their Engine HP. HOWEVER, they always add in a MASSIVE number. You see 10% loss is normal (100HP wheels = 110HP engine) but I see people doing 20% and 30%. When you add in the wrong numbers you always get the wrong answer.

I have also seen some REALLY fake dyno sheets. We had a customer supply us with 2 dynos because he claimed he had over 300HP, with a supercharger and still had the stock transmission and rear end. When he scanned and emailed his dyno sheets we found his issue. The dyno guys wanted to GIVE him the numbers he THOUGHT he was supposed to see. So after 10 runs not getting it they sent him away for some "tuning". At that time the increased the dyno's correction factor to almost 80% and fudged the base numbers. But the give away was that dyno sheets print the correction factor on the top.

So when people think they want more and to appease them shops fake the dyno AND they tell them a crazy parasitic loss percentage you end up with people thinking that they have 200-300HP. Drive a new V6 Camero or Mustage and you'll see you just don't match those 300HP machines.

With all that said.... Can you get 175HP? YES
Will it really be that streetable? Not really
Will it cost you 20K or more? Yes and most likely considerably more since you really need to use PFI
Would you better served thinking in numbers 140-150HP? 100%

[MykeNytemare]

Hello,

it all comes down to control. The more precisely you can supply the perfect amount of fuel and air for a given load/rpm situation and the ignite it at just the right time, the more power your engine will produce. This is why FI beats carbs every single time.

And it's also why Wasted Spark or better yet Coil on Plug beats distributors every time. I'm not saying a distributor will fail, that is highly unlikely. I'm saying that you will not reach your 175hp target with one. Nor will you have any sort of tunability. Sure, back in the day someone somewhere in a shed was able to change the weights in a distributor, but those days are long gone. You could run a rotating dizzy and something like the CB Performance Blackbox. I plucked around with that in combination to bike carbs for a while. It's a capable combination.

For intake manifolds, my got to shop is http://www.danstengineering.co.uk

Yes, CV carbs are much better at supplying the ideal air/fuel mixture than IDFs, DCOEs etc etc. You have the talented Japanese engineers to thank for that.

Bike carbs come with their own set of drawbacks, however. You need to build your own linkage (easier than it sounds) and as far as jetting is concerned...who knows! You'll just have to try what works.

I'll be doing it to my car Fiat later this year. Or not, depending on how well my Weber 34ADF performs.

Cheers
Steiny

If I wind up going for R1 carbs instead of IDF44s, do you have advice on the electric fuel pump/return line and what might be the best way to set those up? Im wondering how the carbs will function if they have a constant (slightly pressurized 3-4 lbs) supply of fuel pumping with no return line provision when the bowls are full. Will I run into leaks or issues and such as most carbs are gravity fed from the tank (in my limited experience)? Just looking for advice as this idea sounds promising if spending over $100 on IDF44s and an intake will not yield driveability and reliability.

[MykeNytemare]

I will upset a lot of people by saying this but head work isn't going to get you 175HP.

With all that said.... Can you get 175HP? YES
Will it really be that streetable? Not really
Will it cost you 20K or more? Yes and most likely considerably more since you really need to use PFI
Would you better served thinking in numbers 140-150HP? 100%

Matt, I'm sure I'm going to reach out to your company for most of what I will need for the engine build... But there seems to be people who believe IDFs are never good and others that say when dialed in they are fine. I tend to believe they can work well even if antiquated in their technology. I had a Mopar with a six pack that the previous owner said never ran and others said didn't make more power. With a little money and work it was a beast on a 440.

Where do you stand on carbs for a high output build (if carbs are the choice as they are for me)

[Jon124]

I had a Mopar with a six pack that the previous owner said never ran and others said didn't make more power. With a little money and work it was a beast on a 440.

Your comparison to old V8s is not relevant. These engines made a lot of power obviously because of their massive displacement. Let’s do some math.

The 440 6 pack is rated 375hp (https://www.hemmings.com/blog/article/c ... -six-pack/) and is 7.21L

375/7.21 = 52hp/L

The most powerful fiat spider is the 2L fuel injected at 104hp.

104/2 = 52hp/L

Very interesting, the fiat is already at the same power level. You want to increase the fiat to 87.5hp/L, this probably won’t happen with 1970s technology.

[MykeNytemare]

I had a Mopar with a six pack that the previous owner said never ran and others said didn't make more power. With a little money and work it was a beast on a 440.

Your comparison to old V8s is not relevant. These engines made a lot of power obviously because of their massive displacement. Let’s do some math.

The 440 6 pack is rated 375hp (https://www.hemmings.com/blog/article/c ... -six-pack/) and is 7.21L

375/7.21 = 52hp/L

The most powerful fiat spider is the 2L fuel injected at 104hp.

104/2 = 52hp/L

Very interesting, the fiat is already at the same power level. You want to increase the fiat to 87.5hp/L, this probably won’t happen with 1970s technology.

That would definitely be true if those numbers were really accurate! The factory hipo engines likely made way more than that and had higher compression than the TC engine. Even if that isnt the case, the engine I had put together with cams, mild porting, even higher compression and such dynoed at 622hp or thereabouts with the 6pack. If thats about 75hp/liter, then making about 150hp total out of the 2.0TC is not a ridiculous task, right?

I am just looking to figure out what type of fuel delivery I will be doing before I start tearing down the block this winter so I can build a great carbed engine (with whatever limitations that may have). I was set on IDF44s but am open to bike cars or whatever as I know I will be putting some money and time into it. Maybe someone will come along and say I don't need IDFs.

I understand your point and maybe I should not have even put HP numbers. I just want to "do everything right" for this type of build so that I end up with the nicest carbed engine I can have for the Spider that makes really good power compared to stock or the limitation of the engine.

[AndyVAS]

You can get very similar peek power numbers with EFI, IDF's, or DCOE's. What you won't have are the same average power numbers over roughly a 3k rpm range. With modern fuel, carbs don't have a very long life. Plan a rebuild every couple years and replacements every 5-10 years.

[SteinOnkel]

Set the bike carbs up to receive 3,5 lbs of pressure.

I have yet to meet anyone who says that IDFs, DCOEs, whatever run great. Just last weekend I was at a car show interviewing these folks. The answers to "How does it run?" ranged from "Okay-ish" to "My 2.0l is getting about 12mpg". I'm also not suggesting bike carbs are the cure-all. They are simpler, cheaper and much more reliable than the old webers, solexes, dellorots. They run better, but not great. And jetting them will be an exercise in patience.

I think you're also a little quick to dismiss EFI outright. An MS2 setup will set you back less than a set of IDFs. It it is more work though, no way around that.

At the end of the day, pulling 175hp out of your engine as naturally aspirated is not going to happen easily.

[seabeelt]

These topics/discussions always make me go ... LOL!!! and Hmmmmm.

Trust me when I say I'm not being critical or disputing anyone's opinion, nor are my comments meant to offend anyone.

First, is WHY would anyone want to spend that amount of money on a car destined to be on the street? Meaning you are going to spend money to get to 175 hp so you kid can drive it in 7-8 years (think screaming engine and no air bags in the hands of a 16 year old) and you want to put your wife and two kids in a two seater (forget it has a back seat -its an upholstered package shelf with no seat belts.

Second, WHY would you argue with a guy/company that routinely builds these engines for customers????/ Just saying

Third, (really probably First) WHAT are you going to use the car for? Racing? - OK, Track?, OK-Maybe, Street? Ummmm probably not. If you want that kind of HP go buy a Dodge Charger Hemi or something of the sort that has that much grunt.. it would be money better spent IMO

Fourth, After answering the Third one go back to the First and Second questions. Also as a primer go read Brad Artique's assessment of the engines and carbs for the fiat spider. (My car is a 1608 ( best rated hp off the line for American purchase running only dual idfs, and a 4-2-1 exhaust - the car has quick revs, I can (if I want get rubber in two gears) and I routinely get 30 mpg highway and it pulls strong across the rpm up to the red line (I don't push it beyond that though the throttle is still responding) I'm running stock rims and 13" tires. I drive spiritedly. I like to push the revs and hear the carbs open up. It will easily cruise 70 and will slip up to 80 if I'm not looking. Is it quick off the line, no, Is it quick in the quarter mile, no. Is it FUN to drive, ABSOLUTELY! Are there better set-ups SURE, but this works for me. I don't have to tune them often. I do a cursory check once a year to make sure they are still all matched and teak as necessary if at all.

Fifth as mentioned, the tranny and rear end cant handle that kind of torque/hp without serious modification or swap out. Take a look at V6Spder's project(s)

I could go on and on, but I think the points have been expressed.
respectfully