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I have Alfa 10548 Euro cams in my 1750 Super, with Webers, otherwise stock, and in my 2000 GTV, with Spica, with Norman Racing big-valve head. They're not high-rpm cams really, but they perk up both engines noticeably compared to the stock US 1750 and 2000 cams. Definitely more bottom and mid range, and yet they seem to rev better too. These is all seat-of-the-pants testing, not dyno.

These are both engines that don't often get near their 5800 rev limits, so if you're looking for 7000 rpm cams these aren't it. But for everyday street use, back roads, and mild track applications, they're great, and require no machining or other special work to install. Set at 102 lobe centers.

Andrew Watry
 

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I wanted to buy a hot cam set for the fuel injection 1989 Spider, spoke with the guys at IAP and they kind of talk me out of it.
The seller mention that in the fuel injection cars, hotter cams tend to mess up the idle.
How true is that?

Alfonso
 

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I'd be quite interested to know of feedback on the Megacycle cams that Jon Norman sells, and if anyone has bought the OS Giken cams sold by Anthony Rimicci. Good hard data please .... this is for a warm street 1750 running on good high octane (98+) unleaded, maybe with Motronic 10:1 pistons (undecided), moderate head work. I have the Colombo and Bariani 10.9mm cams but I'm not sure if there are better profiles out there now. Looking for good torque figures rather than outright horsepower. Decisions, decisions ..........

Alex.
 

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I've had the 10548 and the Shankle 7L cams on two different cars with SPICA. The 10548 was peppier than stock otherwise the motor was a stock rebuild. The 7L's were mated to an enhanced pump and 10 to 1 pistons, very strong; both cars were flexable but the 7L's were weaker under 3000rpm and stronger above. Current Spider has 40mm webers, 10.1, ss header and exhaust with 8L cams (lightened flywheel), banshee sound and performance, strong bottom end, takes off above 4000rpm; not as comfortable though in stop and go traffic, plugs seem to load up a little.
 

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Interesting thread. I am reluctant to spend $$ on bigger valves and head work in my 74 spider with its original Spica. Question: Will swapping stock cams with "Euro" cams -- and no more other head work - aid measurably in performance ( I will be installing them myself)? What of diminshed low-end/torque? I do have a high flow exhaust and a better breathing filter/intake. Having surfed "cam" threads,this discrete question is never answered directly. Thanks in advance if anyone has experience or information about this particular inquiry.
 

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silverspider said:
Interesting thread. I am reluctant to spend $$ on bigger valves and head work in my 74 spider with its original Spica. Question: Will swapping stock cams with "Euro" cams -- and no more other head work - aid measurably in performance ( I will be installing them myself)? What of diminshed low-end/torque? I do have a high flow exhaust and a better breathing filter/intake. Having surfed "cam" threads,this discrete question is never answered directly. Thanks in advance if anyone has experience or information about this particular inquiry.
I replaced the original cams with 10548, no other motor work, no other mods. It definitely perked up the motor, in my opinion. I haven't had it on the dyno but bottom end seems stronger and it definitely likes to rev better.

-Jason
 

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silverspider said:
Interesting thread. I am reluctant to spend $$ on bigger valves and head work in my 74 spider with its original Spica. Question: Will swapping stock cams with "Euro" cams -- and no more other head work - aid measurably in performance ( I will be installing them myself)? What of diminshed low-end/torque? I do have a high flow exhaust and a better breathing filter/intake. Having surfed "cam" threads,this discrete question is never answered directly. Thanks in advance if anyone has experience or information about this particular inquiry.

The 10548 made improved performance withe stock engine, remember you have to remark the cam caps to time properly, different lobe centers.
 

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This thread is getting very confusing!

Spiders used 4 main fuel delivery systems and they all have different requirements for cams.

For example, the 10548 cams have 1mm LESS lift than the stock cams on a Motronic Spider. Make sure the advice you're reading applies to your Spider.

Joe
 

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JoeCab said:
This thread is getting very confusing!

Spiders used 4 main fuel delivery systems and they all have different requirements for cams.


That is what I want to know!
My Spider 1989 with Bosh L-jetronic ignition have a specific set of cams (for FI cars) sold at IAP and Centerline.
But some people say that is not worth it on FI cars and they will do mor wrong at idle than good.
How true os this?
I am also looking at the bigger valves head from Centerline. Would that complenet a set of hot cams?

Alfonso
 

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The reasons these questions never get clear answers is because the questions are too broad to answer easily. In order to select a cam you have to know the answer to the following questions.

1. For what reasons are you dissatisfied with your current cams?

2. What are you trying to accomplish by replacing the cams (better acceleration under 3,000 rpm, over 4,000 rpm, more torque, more hp, better mileage, can't stand having a smooth idle and good driveability, tired of getting laughed at at the local Alfa club for using stupid stock cams that the doctors and physicists at Alfa Romeo spent a tremendous amount of time and research developing to be the best all around cams for your car, want to get a 5% bump in top end hp and loose mileage around town and mid range torque)?

3. What modifications have been made or are going to be made to the engine? Compression ratio, head work, exhaust systems, ignition (to a lesser degree) and induction system have a lot to do with good cam selection. What is your final drive ratio (stock gears and tire diameters)?

4. Where do you like to keep the rpm band? Does it bother you to rev your engine up to more than 5,000 rpm? Do you mind having to down shift below 2,500 rpm or risk bogging the engine? Is your idea of a good time trying to beat rice burners at stop lights, or barn storming through back roads?

5. What tradeoff are you willing to make in the power vs reliability arena?

6. Where do you do your driving? All track, around town, highway, touring, or a mixture of all of these? Where do you want to optimize your cam use?

An engine is a system and seldom changing any one part of a system will pay large dividends. Think chain and weakest link. That being said the cam is the single most important part of the engine in determining its personality. But it is limited by other parts of the engine as well. Keep in mind, the best one size fits all cam is probably the one Alfa designed for your engine.

Cam selection is quite complicated and you need a pretty good understanding of engine building theory to understand the trade offs. Or, you need a bunch of experience with different cams and different setups. Unless you understand the relationships between everything I have talked about, you are better off calling up Centerline, Paul Spruell, or Wes Ingram and having them talk you through cam selection or getting the work done by a shop that has a lot of experience in cam selection. If you post the answers to all the questions I wrote here, I am sure we will all chime in with our opinions as well.

Best of luck,

Mike
74 Spider
77 308 GTB
65 E-Type
65 Sport Fury
 

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This is topical. I changed cams in my S2 spider toady. Out went the US spec cams and in went Euro 10548 cams. The difference in performance is very noticeable. The idle and pickup are not affected but the mid range is much better and there is a small improvement at the top end. The job would have taken 2 hours if I had not dropped a bolt into the engine. It took another 2 hours to retrieve it.
The engine is a well worn 2L that I bought from Bill Sinclair. It came out of a 74 Berlina but it almost certainly is originally from a 79. It has standard pistons and Webers on a Euro manifold.
Ed Prytherch, Columbia SC
79 Spider
74 GTV
88 Verde
 

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Point(s) well taken Mike. But as I understand it, European delivered cars differed from the US versions in 1974 in one material respect, the camshafts. A swap seems like a simple way to gain a bit of power.

Then again, I've been wrong before ............
 

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silverspider said:
European delivered cars differed from the US versions in 1974 in one material respect, the camshafts.
There are those that would argue that the induction system is a material difference...

I do know that contempory road tests published the following:
76 Euro 2L Spider (Autocar July '76):
BHP Torque Ft/lbs 0-30 0-60 1/4mile Top Speed
[email protected],500 [email protected],500 3.3 9.8 17.1 116

74 US 2L Spider (R&T Dec '74)
BHP Torque Ft/lbs 0-30 0-60 1/4mile Top Speed
[email protected],800 [email protected],500 4.3 11.0 17.1 118

72 US GTV (R&T Aug 72)
BHP Torque Ft/lbs 0-30 0-60 1/4mile Top Speed
[email protected],800 [email protected],500 3.3 9.6 17.6 110

This indicates that HP varies 3.1% which is within measuring error, torque is the same, acceleration times vary within driver error (the 74 US Spider appears slower, but it also looks like it launched slower, look at the 1/4 mile time, could be some variation in low speed acceleration.

Now I haven't back to back dyno'ed a Euro cam vs a 74 fuelie cam vs any other cam on a bone stock engine. I am sure it would be illustrative. But, all quantitative results I have seen seem to suggest that the differences are not huge. I don't mean to completely discount seat of the pants dynos, but a description that it feels better in the mid end or top end pulls great is no substitute for measurements. A simple stop watch and some 0-30, 0-60, 40-60, 60-80 runs will give an awful lot of useful information. Its stunning to me how little real data is available on this subject.

I can tell you that every inexperienced owner I have ever met who dyno'ed their car was unpleasantly surprised at the numbers. It really is quite hard to improve on the factory engines, and it costs a lot. Its the reason we love them so much. Don't get me wrong, I love building high performance engines, but its not a quick and easy process. There is one caveat, the post 75 Spica cars were crippled, putting an early factory cam or similar does seem to help along with changing the ignition timing. The guys at Centerline really will help you choose well if you don't know what you have.

Mike

PS Pages 38 to 46 in Jim Kartaalalmakis's book has a good discussion on cam theory and pages 7 to 104 have a good, albeit brief, explaination on how to beat the Alfa engineers at engine building.:)
 

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Vantaaj said:
There are those that would argue that the induction system is a material difference.............

I would submit that many of the specifications listed in the "contemporary" publications were contradictory. Alfa gave misleading and incorrect data and the magazines of the day repeated and muddled it further. Also different scales were used. That said the the factory itself claimed a horsepower difference between the early and the later 10548 cam. To repeat, I had a bone stock rebuilt 72 FI with standard pump and a Plex as the only upgrade, the change from the USA cam to 10548 made a noticable difference. I agree upgrading must be tailored to the total system. Specifically to the SPICA (71-79) with the 4 to 2 header (71-74) the 10548 makes a noticable improvement. I've owned and driven reguarly about ten of these cars.
 

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rogerspeed said:
Specifically to the SPICA (71-79) with the 4 to 2 header (71-74) the 10548 makes a noticable improvement..
True! Installing the 10548 cam does wake up a Spica engine a bit with no other changes, and they are a very nice cam for most people.

HOWEVER, it's not all the cam. Let me explain. The stock cam TIMING on the Spica cars wasn't the best, and I believe it is why many people believe a 2 liter engine doesn't like to rev.

So, if we install 10548 cams and set them up with Euro cam timing, you might get a 4 hp improvement. But, simply retiming the stock cams to the same cam timing might give you 2 of that 4 hp.

So many variables...

Joe
 

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rogerspeed said:
I would submit that many of the specifications listed in the "contemporary" publications were contradictory....

the change from the USA cam to 10548 made a noticable difference...
I totally agree with and understand your first point.

On the second point, I think you are proving my earlier point that actual data is unavailable.

I am being totally sincere when I say that I don't know what a "noticable difference is". I can say that cam 10548 has 8 degrees more total duration, 25 more degrees overlap, and .020" more lift than cam 10520 (74 FI cam). This probably translates into maybe 5 more hp on the top if I am being generous, a slightly less smooth (but by no means rough) idle, and I doubt it changes the torque point much at all. Now, I am guessing. I am guessing because I have never read a before and after dyno test of this cam swap with nothing else done.

Shankle rates the 10520 cam a 4 and the Euro a 5. Call me dense, but this is meaningless to me.

Originally, I was trying to point out that cam selection has many variables and that with all the conflicting information available to the Alfa community it even further muddies the water. The only real way to know what works is to either try it yourself or ask for the help of someone who knows from experience after you tell them your needs.

I am not, nor was I ever, trying to say don't change your cams. I have never heard of someone not liking the 10548 Euro cam for reasons other than not enough top end.

I changed my cams as well. I bought the 253 degree 12mm delta cams from Wes. They are make their power later than my XK-E, at the same time as my father's 88 M5 and earlier than my Ferrari 308 GTB. My raw dyno numbers (uncorrected for high altitude and temperature) are: at the rear wheels peak torque is 100 ft/lbs at 4700 rpm and horsepower is 100 at 5600 (with altitude correction the numbers would be about 20% higher). The engine at time of testing was a 2L with motronic pistons, stock ignition, stock exhaust, Ingram HP pump, cleaned up heads with stock valves, and an aluminum flywheel. Due to the peculiarities of the Spica pump, it has not yet idled well since I built the motor six months ago. I am planning on installing the centerline distributor to improve the idle. It also runs excessively rich at all rpm. When I get time I will fix this. At sea level, the car's 0-60 time is roughly 8 seconds.

I love my cams. Stephen from Centerline rather hates them. The president of the local Alfa club has Delta 254 degree 12mm and 246 degree 11mm wishes he had the the 254/12 on both sides for his street/track car. The ACOC VP loves his Euro cams. Cam choice is complex and personal. That's my only real point.

Mike
 
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