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For the last time it is all avail.in the AR Perf options catalouge and Techspecs!! Stop misleading people that this is some sacred data that can not be found. My gosh. Ask any expert who has a set and they can help you out. I can provide you about five who have already done this work if the manuals don't help you. I have a set thank you.I guess you are the only one in the world who knows the correct info, disregarding everyone elses work, including all the engine builders listed. A self proclaimed guru, and you are the only one that knows anything. Unreal really.
 

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Re Mystery Camshafts

I finally got up the ambition to go out to the garage and find my notes from when I degreed in the 105480320051 cams. I installed these when I had the head off for a refresh. The cams I removed where the Euro spec 10548 so-called performance rank 5 cams, so I am familiar with both. The 051 cams are definitely different, requiring relieving the cam follower bores to allow for the extra lift. These 051 cams are not a regrind, the base circle is as per the standard Alfa spec. My notes indicate a 11.0 mm lift, but I did not note whether this is allowing for the valve lash clearance.

I set the clearance at .017" Intake and .019" exhaust. At this clearance the Intake measures 292 degrees duration seat-to-seat and 240.5 degrees at .050" lift. Lobe centres were set to 102 degrees.

My copies of the Performance Option Catalogue and the Competition Advisory binder does not list the 051 cam, nor does the excellent Kartalamakis book.

The mystery deepens...?
 

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FYI- As Jim K. will tell you those are the exact same specs as the GP1 cam as he has to me many times.

Most likely the "051" cams are GP1 cams directly from AR/AD that were not labeled correctly. AR was not perfect as many of us know.
 

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Here you go.

So when do we get a thread with a comprehensive list of all the camshaft numbers and what their applications are for 105 series cars??!! This would be very useful to all and if an expert does it then it will stop alot of the rehashed questions being asked on the BB. I know it is pretty hard to find the info these days due to the glut of threads. Could be a sticky...
 

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Richard Jemison
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Mystery Cams no More

The 051 cams are definitely different, requiring relieving the cam follower bores to allow for the extra lift. These 051 cams are not a regrind, the base circle is as per the standard Alfa spec. My notes indicate a 11.0 mm lift, but I did not note whether this is allowing for the valve lash clearance.
I set the clearance at .017" Intake and .019" exhaust. At this clearance the Intake measures 292 degrees duration seat-to-seat and 240.5 degrees at .050" lift. Lobe centres were set to 102 degrees.
My copies of the Performance Option Catalogue and the Competition Advisory binder does not list the 051 cam, nor does the excellent Kartalamakis book.

I finished profiling the 51 and 01 cam, and sent the data back to the cam owner. Since he paid for the data, it is his to share or not, but it is significantly different from the 115xxxxx32 cam commonly refered to as the GP1, which was a flat flanked lower duration cam better suited to the F.I Alfettas. It has more duration everwhere particularly mid & upper flank & nose than the "32/GP1", and above .200 it makes the 01 look anemic.:eek:
DBEST is totally correct, in his lash settings, and OK on the lobe centers. His duration with lash at .019 of 241 degrees at .050 is close. As in checking the seating area of the ramps I measured duration off the seat from .014 to
.020, and at .020 off the seat got slightly more duration than he did at .019 and he should have had a couple or three degrees more, but measuring in a motor is difficult. A loss in duration on Alfa cams at these lash settings, of around .010 to. 012 is normal.
It is the nicest flank & nose I have seen in all of the Alfa Romeo / Autodelta etc. "OLD" designs for general, high performance, street and track use. Make no mistake it is not a heavy nose racing cam, but a enhanced 10548-01 with more duration & lift where it counts for performance & not early to kill lower end.
I am sending the 51 cam for restoration, and in return am getting to copy it!
:pMashed Potatoes & Gravey!:p
 

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Maybe I can help partly defuze the situation here...do you know how many seemingly 'original' cams (of all types) were lightly reground at some time or other and subsequenty passed from hand to hand?? Each successive owner can swear (in all honesty) that the specs are xyz, unaware of the previous history! And don't tell me you can always spot a regring job...if its properly executed mild reprofiling you'll never spot it. My point is, you can only be sure about an original profile, one you were the first to take out of the Alfa or Bariani or Alquati box. I was lucky enough to be in this position many times, although I live in a place where 9 out of 10 performance cams are regrinds of 10548 cores or (more recently) the Alfa 75 carb cams which have huge lobes able to comfortably accommodate any Godzilla profile without undue base circle reduction. You can only compare apples to apples...and no, I don't want to get involved in this cam war!:cool:
Jim K.
 

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Richard Jemison
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There`s no war

These cams were not regrinds, or modified cams of any sort. These were the same cams I had in `72, and DBEST has in his motor. So they were not on someones list, nor were several sets of cams furnished series teams over the years. It is just another set of cams..... You can`t add the kind of duration these cams had to any known Alfa stick. & they all carry their own cam number distinctly on the core. It`s a very nice cam. Be happy it`s turned up and been acknowledged.:rolleyes:
 

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FWIW, having driven these cams in Don's car, I must say that they are one of the nicest cam set-ups I have ever driven in a street driven Alfa. The Grp 1 cams - which I have in one motor - just don't cut it and feel flat in comparison. Now, I haven't tried Megacycle (developed Pitatore regrind) as sold by Alfa Parts yet, which according to some are the ticket ...
 

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C&B offers new on their website (link below)

AR.SM2 10.9 Lift, 280° duration at 0.050
and
AR.CT2 10.9 Lift 296° duration at 0.050 (These seem better then this "new 10548 "01" that magically popped up from AR over the last 30 years that no one else have ever seen measured at the ratio's quoted above).

http://www.colombo-bariani.com/catalogo.php?lang=eng

Alleggerita,

Is he using them on intake only or in. & ex? AlfaR7 does not have a set of Gp1 115xxxxx32 cams so I am not sure how he is measuring them, rather using published figures?



FWIW, having driven these cams in Don's car, I must say that they are one of the nicest cam set-ups I have ever driven in a street driven Alfa. The Grp 1 cams - which I have in one motor - just don't cut it and feel flat in comparison. Now, I haven't tried Megacycle (developed Pitatore regrind) as sold by Alfa Parts yet, which according to some are the ticket ...
 

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Richard Jemison
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Cam comparison

C&B offers new on their website (link below)

AR.SM2 10.9 Lift, 280° duration at 0.050
and
AR.CT2 10.9 Lift 296° duration at 0.050 (These seem better then this "new 10548 "01" that magically popped up from AR over the last 30 years that no one else have ever seen measured at the ratio's quoted above).
ROSSO, ROSSO, ROSSO! :rolleyes:
Rosso`s comparison of these cams to street 105480320001 cams and the 51 cams he know`s nothing about is totally inapproiate. If he understood cams, when at C&B`s website, he would have understood that these cams are PURE race cams with over 80 degrees overlap each. As well the cams measurement of duration is not at .050 as he states, but is the "total duration" builders quote which happens to be at .020 or .5mm the industry standard.

As to comparison with the GP1 "32" cam I used published data. But it appears my analysis from the profile comparison was "right on" from the personal comments.

As to the 1054800320051 cams profiling, that data has been given to me to dispurse as I see fit. That data will be published in another post in short form. But still more than other suppliers would ever publish even to buyers.

The cams are being directly copied from the oirginal 51 cam and will be available through my web site. They are not listed yet but just inquire.
I do not do this as a business, as most of the older Alfa community know I do this as a hobby, because I enjoy designing cams to specific application, particularly V6 cams. I will make 2 and after that it will be by request.

I have been trying to find a way to post a columnar comparison but the BB site scrambles it.
I can be contacted direct for more information but please use the email link as data cannot be easily transfered on this board.
 

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Richard Jemison
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10548003251 and 105320001 Cam Comparison

I profiled both the above cams last week and copy below some information from my web site regarding these. The Website info should be up tomorrow.:rolleyes:
1054800320051 and 1054800320001 these cams were applications by Alfa Romeo in the 1750 & early 2000 ROW cars. The "51" cam has been relatively unchampioned but several examples are confirmed, just within the BB group recently. They are a factory marked cam and not a reproduction/regrind as some have suggested. Lobe shape indicates good application for F.I. cars because of shorter opening ramp than stock 105480320001, & the early flank`s duration carried into the nose, suggest a good HP Street/Track Day application. It has a much better lobe shape than the "01" cam. Seating (lash) area is profiled at .014 to .022 from base circle. Because of old ramp design, I suggest lash settings of .020 for intake & .021 exhaust to reduce "wasted ramp duration" bleeding off effective use. Note: The "51" cam is a different profile from the 115010320032 cam everyone refers to as the GP 1 cam (10.9 lift 246 @ .050). These cams were around before those, and have a much better profile. The "32" cams were flat flanked cams that were "hammers", that would not make good HP Street / Track cams like the "51" cams. Statements from people who have driven the "51" cam confirm its excellent performance & drivability, unlike the "32" "GP1" cams which were very flat except at high RPM. Understandable as the "32`s" were designed as "lower performance " race cams. and designed for track use.

Alfa Romeo 10548 03200 51 Cam 10548 03200 01 CamLift at Cam Duration at "0" lash
“51" “01"
.020 284 286
.050 252 230
.100 229 211
.200 185 168
.300 137 118
.400 68 10
.430 26 Max .401 10.2 mm
.434 Max lift 11.04 mm
Lobe ctr. 102 99.5
 

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Need dyno results between the two on a stock 2L.
As you can appreciate "seat of the pants" is misleading and does not show true ratings. I still beleive (until proven otherwise hopefully) the GP1 cam will make more power on the dyno.

You need to do a comparison of both at 0.050". The GP1 "32" cam specs are as follows.
Lift(mm): 10.92
[email protected]"(1.25mm): 246*

In addition it would be nice to see mixing of the two with one on the intake and one on the exhaust and vice versa for comparitive runs on a stock 2L to verify best setup.

You say that the "51" cam came before the "32" GP1 cam but why would Autodelta have made the "115010320032" grind after it did not produce more HP for the Group 1 factory street prepared race cars entered by AD in 1972 & 1973?

http://www.alfabb.com/bb/forums/showthread.php?t=36793&highlight=Autodelta+GTV

From the owners that have actully experimented (lets see if they will post on this board) a GP1 "32" cam on the intake and a std. 10548 or a GTV USA spec cam on the exhaust.

Alfa Corse did a test back in the day and used a 12mm cam on the intake(you have to notch the follower bores) and a US Spec 9.6 lift cam on the exhaust and recorded 154.4 HP at the flywheel on a stock car. If anyone would like to see the sheet from Alfa Corse I have it in .pdf format.

I profiled both the above cams last week and copy below some information from my web site regarding these. The Website info should be up tomorrow.:rolleyes:
1054800320051 and 1054800320001 these cams were applications by Alfa Romeo in the 1750 & early 2000 ROW cars. The "51" cam has been relatively unchampioned but several examples are confirmed, just within the BB group recently. They are a factory marked cam and not a reproduction/regrind as some have suggested. Lobe shape indicates good application for F.I. cars because of shorter opening ramp than stock 105480320001, & the early flank`s duration carried into the nose, suggest a good HP Street/Track Day application. It has a much better lobe shape than the "01" cam. Seating (lash) area is profiled at .014 to .022 from base circle. Because of old ramp design, I suggest lash settings of .020 for intake & .021 exhaust to reduce "wasted ramp duration" bleeding off effective use. Note: The "51" cam is a different profile from the 115010320032 cam everyone refers to as the GP 1 cam (10.9 lift 246 @ .050). These cams were around before those, and have a much better profile. The "32" cams were flat flanked cams that were "hammers", that would not make good HP Street / Track cams like the "51" cams. Statements from people who have driven the "51" cam confirm its excellent performance & drivability, unlike the "32" "GP1" cams which were very flat except at high RPM. Understandable as the "32`s" were designed as "lower performance " race cams. and designed for track use.

Alfa Romeo 10548 03200 51 Cam 10548 03200 01 CamLift at Cam Duration at "0" lash
“51" “01"
.020 284 278
.050 252 230
.100 224 211
.200 185 173
.300 165 118
.400 85 10
.430 26 Max .401 10.2 mm
.434 Max lift 11.04 mm
Lobe ctr. 102 99.5
 

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He didn't say the 51 cam produces more horsepower, just that it's a better street / track cam than the GP1 which was designed as a pure track cam. I can tell you that my 2L with the 51 cams is very flexible at low RPMs and has a strong midrange. I was pleasantly surprised, to tell you the truth, as I was expecting something a bit peakier.

Richard, from what I've read you're a proponent of a milder cam on the exhaust. If I were to swap out the 51 cam that's currently on my exhaust with a standard 10548 what kind of effect would you expect to see?

-Jason
 

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It may be that the 105 4803 20051 cams were stock euro 2.0 late model alfetta engine cams. I am having it researched. Other thing to note is that with the "51" cams you most likely will need to relieve the cam follower bores to allow for the extra lift?

What is the base circle measurement on these cams? 30mm?
I beleive most other euro cams have around 27,5 base circles. This needs to be verified.
 

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Jason,

I beleive the differen't cam on the exhaust is used due to the too big stock exhaust valves. Having a reduced ex. cam helps alleviate this problem. Jim K. talks alot about this in his book.
He didn't say the 51 cam produces more horsepower, just that it's a better street / track cam than the GP1 which was designed as a pure track cam. I can tell you that my 2L with the 51 cams is very flexible at low RPMs and has a strong midrange. I was pleasantly surprised, to tell you the truth, as I was expecting something a bit peakier.

Richard, from what I've read you're a proponent of a milder cam on the exhaust. If I were to swap out the 51 cam that's currently on my exhaust with a standard 10548 what kind of effect would you expect to see?

-Jason
 

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Richard Jemison
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Cams specs at .050??

ROSSO, ROSSO,ROSSO,!:rolleyes:
It may be that the 105 4803 20051 cams were stock euro 2.0 late model alfetta engine cams.
Except that they would have had 115 or116 prefix numbers on them.:eek:
Since you think dyno comparisons are so important. I am asking you to tell the group what we should see in the way of Dyno results that would indicate why one cam is superior to another cam. Supposing same motor same day same dyno properly tuned.
Please, we are all waiting with abated breath!
The base circle of the cams both 01 & 51 were 1.080 (27.50mm).
When the info on the site comes up it will have a direct comparison of the
"32" with the 2 shown on this site. You will see why the GP1 cam is a piece of crap unless it`s all you have.
Do you have a car with them in it? And that is a direct question.

How do you know I don`t ? haven`t? had a "32" cam. Another ****ing assumption. Want to try an original Autodelta GTAm cam that was an AUSCA original? Just sent it to Gordon to have for his AUSCA motor. It came out of mine!
We wait your responce to my questions.

Richard, from what I've read you're a proponent of a milder cam on the exhaust. If I were to swap out the 51 cam that's currently on my exhaust with a standard 10548 what kind of effect would you expect to see?
Jason, If you are using them on the street, probably a little loss of very upper end because of more overlap & less lift, but it could be tuned nicely for the street by adj. the lobe centers, to get a tad better lower & mid range. You can do that with your 51`s as well. Email me. We are reducing the ramp & early flank rate on some "01" cams to use as exhaust in smaller motors (1750/1600) . A cheap way to get a different animal.. And it wouldn`t hurt your`s either. But there is better exhaust cams. But not milder, they may have less early duration but look at the ones I suggest as exhaust cams. All have more duration in the mid & later flank & nose. The idea being not to waste the incoming gasses & entend the power stroke. It **** sure isn`t because of the exhaust valves being too big, because they are not. The size of the bowl & port is barely adequate, You can can fool some of the people some of the time with mathmatical equations, but how many engine builders are going to smaller valves? But ROSSO believes everything Jim K. wrote. I gave my book of his away years ago, but I seemingly recall his waxing proudly about a 13.5 MM lift cams. Am I remembering right? Now if I am I`ll comment on that after my memory is confirmed. :cool:
 
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