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Discussion Starter #1
So I bought a 71 GTV with a 2 litre motor that is supposed to have been "built" by one of the local Alfa gurus, he's since disappeared. It's got Webers and set of 10 or 10.5 :1 pistons. It's also got more oil pressure than any Alfa I've ever owned. The thing that's odd is it also makes more valve clatter than any Alfa I've ever owned (I think I'm up to 12 with this one) People always comment on the valve noise. So I hauled out my shim set and tools figuring that they must be set at .019 and .021. They were at .008 and .010! That's tighter than I usually set them to make them quiet. So I looked at the cams figuring they must have big square lobes or something. But no they actually have fairly skinny lobes like a FI cam, and here's the kicker, no numbers! No numbers cast in and no numbers etched on by hand, nothing, no way to identify them. So, any theories on why they might make so much noise? Steve
 

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Here's my uneducated guesses.

1. Cams are too radical for the rest of the head and don't match the valve springs and they are bouncing off the "F1" cam.

2. Timing chain is just a little loose.
 

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Discussion Starter #3
Nope chain tension was about right, plus it's not chain noise, it's valve noise. As for "F1" cams, as I indicated the lobes are not big and square, in fact they look a lot like standard SPICA cams. The lobes are a bit steep and pointy but nothing too radical looking. It's got a good steady idle and comes "on the cam" around 3500-4000. Any other ideas? Steve
 

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could be 7L cams, recommended .06/.08 clearences, I have had motors with them, no excess noise, HD valve springs required. Are you running a tubular header? Have you used a stethascope? Was the head warped, then the combustion surface milled flat, leading to an angle problem creating noise on the cam to followers side? Have you checked and made sure each brass header exhaust nut it tight? Small leaks there create a ticking. Some engine maybe noisier than others, if it all runs good, doesn't blow-up and the oil stays clean, there will be some other problem.
 

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In general, the less clearance you have, the quieter the valves will be, because the lobes are not slapping the tappets from as great a distance. I just reset the valves on my Berlina (10548 cams), from being tight and they've gone from silent to audible.

Other ideas:
* Valve guide/stem wear that is letting the valves **** as they move in the guides.
* Worn lobes (will feel flat or sharp to the fingers).
* Worn tappets.
* Radically wrong clearance for the lobes you have. Hard to solve if you can't find out what they are.

Andrew
 

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Discussion Starter #6
Was noisy valves, now cams

Huh? I didn't remember that 7Ls got set at .06/.08 that makes sense. My recollection was that the set I used to have years ago had numbers engraved with a dremmel tool or something. I was a believer in SPICA until I got this car with a 2 liter and webers. I've become a convert to Webers, there's a lot to be said for accelerator pumps.

I apologize for opening up this can of wroms again but, I went back and read all the posts on here I could find about cams and I confess it only muddied the waters. The thing I like about a 2 liter with carbs is torque and throttle response. I driven a car with real race cams and fun as that might be on a track I don't think that makes a good street motor. A power band that comes on around 3k would be fine, a lopey idle doesn't matter to me. I was looking at the ever popular C&B and despite the cool Italian name and big price, I wonder about the fact that they seem to be rather old grinds. The easy way out would be some of the Euro cams from the guys in VA or CO. Any comments on the 11mm or 11.3mm regrinds from CO? Or the "Carb Performance" cams from VA? I guess to sum up what I'm looking for is a good hot street grind that's going to get driven hard, but never see a track. thanks, Steve
 

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Spica with the right cams will have excellent response. But it's a matter of preference, you're right. In my experience Spica will be smoother throughout the range, idle better, and pull more cleanly at the top.

10548 Euro cams are a nice boost, but they're not a huge performance increase overall compared to stock US cams. You can fell the improvement everywhere, but it's not a night and day change. Norman Racing figures maybe 5 HP due to these cams.

Andrew
 

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So I bought a 71 GTV with a 2 litre motor that is supposed to have been "built" by one of the local Alfa gurus, he's since disappeared. It's got Webers and set of 10 or 10.5 :1 pistons. It's also got more oil pressure than any Alfa I've ever owned. The thing that's odd is it also makes more valve clatter than any Alfa I've ever owned (I think I'm up to 12 with this one) People always comment on the valve noise. So I hauled out my shim set and tools figuring that they must be set at .019 and .021. They were at .008 and .010!
Steve,

I'll do a little long-distance guess work. It's entirely possible that the noise you are hearing is from extra heavy valve springs. Your motor was modified when it was last built and it has some aftermarket cams which appear to be intentiionally adjusted at .008 and .010. Heavy duty valve springs (like Isky springs) are quite a bit noisier than stock. Along with everything else that was done to the engine, it's reasonable to assume that the mechanic also installed heavy-duty valve springs during the rebuild.
 

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Richard Jemison
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All cams are not created equal

most aftermarket cams are nothing but symetrical lobes. They do not have a "seating" ramp designed into them as better quality cams will have, in order to slow the cam follower seating speed..
You will likely find two worn flat spots on the cam lobes. :eek:One right as the valve seats & inertia takes the follower up against the cam, and another about 30 degrees farther around where it bounces back & hits again.
You definately do not have F1 C&B cams as their lift is 10.82mm. They are as well poor performing pieces for most any application.
See my website for cam comparisons & data.
 

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Race motors are not built for sound, if the power is good, that is the benefit. I think you anwsered your question in the post. You need to talk with the guy who built it. If it pops he built wrong, if its strong enjoy it.
 

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If It was my car I'd pull the cams and send them to Richard to check and/or repair and modify. He designs cams for 4 and 6 cyl Alfas. For a reasonable cost he can produce cams that will perform better than most off-the-shelf, aftermarket hot-rod cams. Since there are no markings on the cams, you really can't tell what you have until they are examined by someone who knows about cams. If you think the cams are damaged or defective, you definitely don't want to drive the car very long or very far.
 

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I had a similar problem with some Euro cam regrinds on my '72 GTV - a lot of valve train noise with no apparent cause. The cams did not have flat spots, the tappets were not unusually worn, the chains were tight, and valve clearance was set a little tighter than factory spec. and yet the head was very clattery.

I ran the car like that for several years and with no apparent problems, but when I switched over to higher lift cams with new tappets the problem dissappeared. I can't say for sure if it was the cams or the tappets that was causing the clatter since both were changed at the same time.

Joe
 

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Noisy valve gear? Ask Richard!

I can second Jims advice as Richard Jemison is extremely well versed with unique Alfa cams and CORRECT applications. Engine replacement :eek: is always much more costly than a pair of cams correct for the application:cool:.
:DGordon Raymond
 

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I had a similar problem after I had a pair for my 2600 reground at a well-known and highly touted 'performance' cam shaft specialty shop here in San Diego:(. Unfortunately they were ignorant of the 'silencing ramp' included in the original profile, and delivered cams that made the engine run beautifully (with clearances at .008 & .010) but it sounded a lot like my friends' Dodge diesel pickup. Fortunately, I had a second pair, and took them to the other well-known, and highly touted cam grinders in the city, with instructions to include a silencing ramp in their grind profile...these I still run today in my sprint, and they are whisper silent, with no other changes made:). Perhaps your cams were ground for performance without concern for silent operation. Cams are so easy to change, and readily available (for your engine type) that I'd try that first. Perhaps you may even be able to 'borrow' a pair from your friendly Alfa repair shop, just to test this fix before investing $.
 

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The Alquati A34s I had in my old alfa were very "liftery", made it sound like a solid lifter V8. In my case it was purely the lack of the seating ramp. If you have the first version of Jim K's book its very easy to see the extended ramps on the factory cams profiles.
I quite enjoyed the sound.
 

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Discussion Starter #16
Guys that was meant to be FI as in Fuel Injection not F1, as in Formula One. Thanks for the input though and I'd still like to hear some reccomendations based on experience with some the various easily obtainable carburated cams out there. thanks, Steve
 

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Richard Jemison
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Cam lobe design/selection/ordering

]Richard, thanks for your reply to my inquiry regrding cams, original post was noisy valves. I suspect the problem is due to them being old Shankle 7Ls set a bit loose. I have been studying your web site and what you have to say about torque, and you've got me convinced. Am I to understand that your reccomendation for a 2 litre street motor would be your 136-785 combo? Can I bolt these up, degree them in, set the valves and go, or will these require notching the tops of the tappet bores to clear the lobes, and a tear down to check piston clearance? To buy a set one simply contacts Webcam directly? Thanks, Steve
The grinds you ask about 136/785, are fairly agressive HP cams and unless most of desired performance is on the track, less might be better.
Since there is nothing but speculation (the Alfa BB`s favorite activity!) on what cams you have I would suggest that you measure (base circle ,(side to side) & lobe (top to bottom) this generally works on street cams) & determine what lift you have as a start, and deciding on desired performance change as a result. None of the aftermarket "pointy lobe" cams in the 10.4 to 10.9 have duration of more than 236-240 at lift at .050. I would suspect these are reground cams with the bodies ground down as well. (will appear to be billet cams) Typically cams with smaller, underground base circles will be much more noisy than the same lobe in a stock (.1080) base circle.
While on the subject of base circles... The typical stock 4 cyl Alfa head will allow fitment of stock base circle cams of no more than 10.5 to 10.9mm lift, without interference with the sides of the cam follower bores. Depends on the year made. By reducing the base circle 1mm you can increase the lift by 1mm. This reduction will require shim thickness increase of .5mm (.0200) more or less. ( Standard C&B base circles seem to be -1.5mm(1.020))

If I was to pick a grind that I would reccommend as a great all around cam for 1750/2liter it would be the RJR 590 grind. It can be used with RJR776 as exhaust( both covered on website) & be very effective for performance yet remain very drivable. Above 11+- lift you enter the world of valve spring bind/piston clearance/valve seal interference etc. 12mm lifts are really only justified on modified heads & racing applications, You get parasitic drag with higher lifts, that are pretty significant. On a street/track day car it really isn`t necessary. But for a track & street oriented 2 liter I would suggest the RJR221/776 (not just for VVT, but modified VVTs are a good idea in a Street/Track application).

Then the next step would be the RJR136/785.

To exceed lifts above 10.5 on 1300/1600 cc motors and 11mm on 1750s is a waste of effort. (I guess I should put IMHO just so I don`t have to listen to other`s who have a different oppinion... I say that as, with available room for valve seat & valve size increases, porting & bowl shaping, more than those lifts won`t allow anymore flow than those lifts will accomodate. More important is the lobe shape above .100 lift and below .040. But what do I know.

There is a possibility that cams with "dumb" lobe design or some of the higher lift stock cams to be reshaped (10548-01 & 51) to reduce overlap & improve lobe design. This is generally less cost, but they must know what lobe design can be ground on the lobe to get the shape needed, as the machine must contact the lobe continuously (removing more material from various areas than others). For this to be done the profile must be known, and what is fitable must be known.

Additionally in the case of 6 cyl cams, you will need how much (in degrees on the camshaft that you want the lobes moved both advanced / retarded, (the new lobe separation/ lobe center) wanted. This is critical not only to performance, but for clearing the pistons, and correct overlap for the design. Any change in Duration & lift will require lobe center changes for both lobes (in different direction and degrees) to perform correctly.

You can order cams to be built direct from Webcam, 951-369-5144, ask for Debbie (AKA "Fluffer"), (there is also a link to them on my Website) but you have to have all the necessary info and specs for what you want or you will likely be sent away for guidance. For 4 cyl. Alfa cams they will want the Grind number for intake & exhaust, and base circle wanted, You must provide cam cores for them to work with. They do not use billets for these, or keep in stock Alfa cams. FYI billets, even hardened are about 30% less durable than their hardweld process:D
 

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I have a set of cams I got from John Shankle that have very low clearances. They actually were ground by Crane Cams - a big hot rod group in the 70's at least - and had their serial number on them. I received the detailed profile from Crane, and that showed that they had start ramps as alfa cams should, but were spec'd to clearances of 0.005 (I) and 0.007(E) inches by Crane. They clattered like a desiel when I installed them as standard Alfa cams are at 0.017 adn 0.019 inches. When installed to Crane specs they were quiet - just a whisper of that wonderful mechanical lifter chatter.

And they were among the hottest cams I've ever had at only 10.5 mm lift.

Anyway, one easy check is to "degree" the cams. Put a dial indicator follower on the cam follower cup, and turn the cam (Be sure that the pistons are not in the way) with the chain off. You can use the cam sprocket as a rough degree wheel if you don't have one. From full closed - the lobe pointing away from the frollower cup - turn the cam half a sprocket tooth, measure, repeat. You can do this with the clearance set to near zero and you'll get the full cam profile, but remember to reset the clearances. You'll get a measure about every 5 degrees this way (sprockets are about 10 degrees apart, but count the teeth and divide into 360 to be exact).

Ir you then plot the measurements on a graph you can usually see if there are open and close ramps, as well as see just what the real duration and lift is.

A lot of the hot-rod cam grinders leave out the lift ramps because they grind to US standard approach of very low install clearances. Pushrod engines even with solid or roller lifters have plenty of slop and flex in the valve linkages so that little clearance is needed for safe operation. This same engineering approach will work fine on an alfa - mine has been running with very low clearances for years, as that's the way the cams were ment to be.

Robert
 

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Richard Jemison
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Fluffer

As you perhaps anticipated, she is orally talented.
She can tell you stories fabricated from pure bull****, and regardless of your awareness of what is happening to you at the time, you eventually hang up the phone satisfied. Not with any substantive increase in your level of information, but satiated, ;) and occasionally "worn out"! :p
 
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