01-29-2008, 08:39 AM
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Richard Jemison
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Join Date: Apr 2005
Location: Pensacola, Fl. U.S.A.
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Cam info continued
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I think most of us want a street cam that will give us an increase in power, pass emissions and have a minimal loss of idle quality and fuel economy. By that I mean still idle under 1000rpm but with a slight increase in roughness, and a fuel economy loss of under 2mpg. Will your mildest cams do that? I suspect they will.
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Greg:
That is the design`s purpose. The cam with 112 LC`s should past Calif "E" test and should with 110 & 110 LC`s as well.. Those LCs will give a bit better pull in the upper range, but when cutoff is around 6000rpm by the module, why not leave the inhancement in the range of street use? Meaning 2000 to 5000 RPM. The injectors are stressed at that point.(see Greg`s site for increasing fuel pressure to the injectors) If your power band is higher in that range there`s no need to twist it higher, except "that you can"... that pairing of LC`s allow "twist' timing a couple of degrees to get 108 - 112 LCs that makes the motor a bit more lively as it revs up, still with stock intake LC so no issues at low end. The idle will be smooth, not lumpy. It is really a matter of nothing but lobe design & timing.
spacing. There is another cam with a bit more intake duration using the same exhaust. It (RJR570/744)has about 3 to 4 more degrees duration accross the range a little more lift, and will give a tad more power than the 28+2.5 (5)/744 cam described above. It is as much cam as the stock FI unit can digest with just a fuel pressure increase. Larger capacity injectors would make it happier. Still designed to be "E" friendly.
Both of these cams will fit in a unmodified 2.5 or 3.0 head without metal removal or other issues.
I will continue from where we left off last night after lunch, if I can remember...
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Richard Jemison
RJR Racing
http://scuderiagiallo.com
"you don`t have to listen, but you won`t win the argument"!
"Nothing that I might suggest will be legal in California"
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01-29-2008, 11:22 AM
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Senior Member
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(Beware: naïve questions alert)
Richard, can a place like webcamshafts.com take a stock pair of cams and turn them into 164S cams? That is, can the lobe separation be changed or is it fixed once the cam is made? Can any of the RJR 12v V6 cams be made from stock cams or must you always start fresh?
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01-29-2008, 03:12 PM
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Wow, this really is superb info on the cams. So question.. the RJR570/744 with slightly increased intake duration, over the 28+2.5 (5)/744 cam. how is the low end compared? is it still fairly smooth at idle? It sounds as if these little beauties are still very streetable over the usual performance cams that are sold.
The lift/duration figures versus 164S results are impressive on the 744 profile, whilst still remianing E friendly, and presumably fuel friendly too. In which case why were alfa so stuck in their ways with lobe design/timing? technology? Would it have been so bad cost wise for them to alter the lobe designs and run with bigger injectors? especially with zero alteration to the intake LC, it would have made no difference to idle quality. In terms of quality are the standard stock cam material specs fairly cheap/poor?
Fascinating stuff.
Last edited by mjr; 01-29-2008 at 03:53 PM.
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01-29-2008, 03:20 PM
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How refreshing!
Finally, some good info on the 'How do I make more power" issue. This one has been tossed around for as long as I can remember. I'm going to post an image ( courtesy of centerline, cropped by yours truly) that displays the stock 12V cams side-by-side by major valve event rather than duration at various lift values. From his numbers, you can clearly see that RJ's design picks up significant duration at .200 and .250. Maybe RJ can then show his cam specs horizontally next to these to get a perspective.
If I could take a stab at answering Maldi's question. Weld-up/re-grinds have historically not had a good reputation for longevity. Though, I suppose with the right equipment and processes, one could manufacture a good product from factory stock - though I would think a profile change would last longer than a high lift design - for obvious reasons. The reason sohc design's are fixed with respect to their lobe centers is because both lobes are on the same cam.
Anyhow, I like his thinking and would rather have 80% of peak torque available at 2000 rpm and keep it all the way to 6000, than a cam that gives me 10hp gain at 7000 (and 80% peak torque at 4000rpm).
Sounds a lot like the Verde cams to me
Richard, what is the most one can mill from a 2.5 head without running into issues with valve/cylinder wall clearances? Also, what would be the compression gained?
Last edited by ToonRboy; 01-29-2008 at 03:24 PM.
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01-29-2008, 09:30 PM
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Richard Jemison
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Join Date: Apr 2005
Location: Pensacola, Fl. U.S.A.
Posts: 839
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Cam info cont....
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Richard, can a place like webcamshafts.com take a stock pair of cams and turn them into 164S cams? That is, can the lobe separation be changed or is it fixed once the cam is made? Can any of the RJR 12v V6 cams be made from stock cams or must you always start fresh?
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All the Alfa cams are started as stock lobes at WebCam, they are hardwelded and built as spec`d by the designer. Contrary to ToonR`s coment, hardwelded cams (Web`s) are the cam of choice for professional Drag bike builders because the high and fast lift profiles they run at big RPMs, will quickly eat up the lobes of billet cams. And , as well there are other builders who`s hardwelding is questionable at best (and cheaper). I won`t argue that point.
ToonR, re; listing in line item format. Look back at the comment I made regarding timing events and Standards. You convert all of that info into timing events based on .050 lift at 0 lash, if you want. Notice the different timing enents from the stock cam page compared to the events on the performance page. The cams with more duration and overlap actually have "shorter numbers at overlap. That is a function of measurement standards. Profile comparisons are what tells the story. The timing events are predicated on lobe placement, as WebCams are made custom these are created so that the lobes where they need to be, for performance, clearance etc... There are no "standard" cams or "in stock" Alfa Romeo cams, all made to "order". Other grinders could make the cams with similar lobes. I published full profiles of some proper pairings and they are there for the Alfa community to do with as you want..
Now back to wherever we were... somewhere back earlier I threw in GTV6 cams in the mix of 108/108 LC cams. The 2.5 cams all were 102/108 LC cams which was my error. The later cars cam equiped with the 119 series cams common to the rest of the Alfa V6 motors other than the "S" and L series which don`t always match technical specifications.
As well the cam numbers don`t match published info either.....
Hey it`s Eye-talian!
However I suggest remembering cams are not just about getting more & bigger. The best results come from proper matching of engine breathing with intended use. Most often way too much cam is wanted and the intake system isn`t up to the task! 4 cylinder Alfa`s with Webers, 6 cyls`s with FI! Mo` cam, Mo` Power!!!
As a rule of thumb, in general with Alfa V6 head designs the intake cams seem to need to be about 10% larger in lift and duration than the exhaust. The intake cams lift rate does not need to be as fast as the exhaust, but the gains come from the faster rates used. Larger lobed cams need to be built only with specific engine clearances known, or planned with. There is a limit to what large lobes can be opened to clear existing valve pockets & work well. As you spread large lobes the power band tilts lower in the rev range. Often this will make a more drivable race car as the torque curve is larger & less peaky (flatter).
Intake ports & such;
The V6 12V motors are a lot like the 4 cylinder Alfa heads, but with bad ports.
The 2.5 and 1750 are similar as is the 2L and 3 liter as to valve sizing. Both the 2.5 and 3 liter share the same size intake and exhaust ports (Say it ain`t so!) to the detriment of the 3.0 even though the valves are bigger. while on this subject the Alfa Sei intakes are much more size approiate than the FI heads, but this is a result of early design, for carbs, verses later design for "E" motors. I used Sei heads on the GT2 car with good results.
However the 2.5 FI heads actually work very well with the port size, and reacts negatively to larger porting and the big runners like Shankle offered. The runner length on the early cars work better for performance mods as they are not as long. The runners are designed for low end enhancement on the larer cars, and all the 3 liters benefit from the larger runners as long as the heads are ported to accomodate the additional inside diameter. In all the motors the area of the ports that need the most work is the area around the bend into the bowl area. Opening that congested area and cleaning up the bowl pays nice dividends. It is, naturally, hard to get at without long stem burrs, and good technique. The finish in the later heads is very basic, and will need improvement. The seats are a bit thick and can be opened at the bowl floor or replaced with larger seats. But, larger seats and valves are not really a good thing unless planned together and done correctly with matched increases in porting & bowl shape.. The stock seat can take a minor increase in Valve head size, if cut correctly. A large valve placed in a stock seat by the average machinist will actually disrupt flow. I have been assisting Jeff Way with a drawing of a well cut valve seat and back cut valves. Maybe by tomorrow it can be posted. Forget the three angle seat myth . We will pick up there... 
__________________
Richard Jemison
RJR Racing
http://scuderiagiallo.com
"you don`t have to listen, but you won`t win the argument"!
"Nothing that I might suggest will be legal in California"
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01-31-2008, 08:07 AM
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"I agree to disagree" seems to be your motto RJ. It sure would be nice if you could answer a question more directly. I understand the concepts of what you are saying but some of it is confusing and contradictary. I asked that you post your cam specs next to the stock one's I posted. You said: "Look back at the comment I made regarding timing events and Standards. You convert all of that info into timing events based on .050 lift at 0 lash, if you want." So, I went to your page http://scuderiagiallo.com/How_to_do_it.htm, and the data is presented in the same way and no, I don't want to have to figure out and convert all that data. I would think the cam designer should do that?
When Maldi asked if stock cams can be welded-up to 164S cam spec you said: "All the Alfa cams are started as stock lobes at WebCam, they are hardwelded and built as spec`d by the designer" Then, turned around and said: "There are no "standard" cams or "in stock" Alfa Romeo cams, all made to "order".
I think it's fair to say that historically, regrinds and hardwelded cams don't last. They may very well be the choice of professional Drag bike builders, but I don't think Maldi want to tear his engine apart as often as they do.
In another post "Grinding of old cams to new profile", you seem to agree with that very sentiment "The hardweld process must be good. Most are not." as well as lobe shaping (to give longer duration past .050) vs high lift/quick ramp with respect to wear. You said: "a pointy lobe at the higher spring rates produced by lift isn`t going to last long"
You certainly have the experience and the knowledge my master, but it wouldn't hurt your image to pontificate a little less. 
Anyhow, I am interested in the RJR28-744 cams but I would like to see how they compare to the stock Verde cams first (easily got & cheap). By the way, what does webcams charge for that cam? I didn't see anything on their web page that speaks to warrantee or guarantee.
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01-31-2008, 09:10 AM
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I also have the same feeling about that! Alfar7/ Richard J. obviuosly has the knowledge, but I think the details dissapear in all the words. No offence, but more concentrated info would be an advantage. Also cam data given the same way as Alfa stock and Colombo & Bariani would be an advantage, in order to be able to compare. Very difficult to compare camshaft data in two different standards. If there is a choice, I would prefer factory standard.
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01-31-2008, 09:31 AM
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seeing that everyone is talking camshafts i need to ask a question about the 24v engines.
are both intake and exhaust cams the same lift and duration on them?? because they seem the same on mine, but i haven't had the chance to take them out and measure them..
about regrinds. there's a guy in england who does them , ahmotorsports he's called i believe. but you are warned; he is quite pricey!!
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01-31-2008, 10:21 AM
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The two of you are missing the point that Richard has made several times, that is that duration at .015 and .050 plus max lift give an incomplete picture of the cam. Richard lists duration at .050 intervals for his cams. AR and CB do not. But you can pull the simple data on his cams to make a comparison with AR and CB but it may not do you a lot of good since you missing the important information about what the cam is doing when the engine is really breathing.
I see no contradiction in what Richard has written with regard to welded cams vs. billets. He has said that there are inferior welded up cams around but the Webcams are the best and are superior to billets. You can choose whether you believe him, but he is not contradicting himself.
If I want to know the price and warranty of a product I call the vendor rather than ask a customer. Webcams number is on the site They have answered the phone when I have called. They start with a core AR camshaft to make a customer camshaft. They do everything to order. Is that confusing?
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Ed Prytherch
79 Spider Veloce
88 Milano Verde
88 Milano Verde
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01-31-2008, 12:17 PM
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No alfaparticle, I think I got that. All of it.
I suppose that I'm out of line asking for a side by side comparison of the stock Verde cam to RJ's 28-744. And asking "how much" from someone who designed and purchased them is just plain rude. Also, my question on head milling and compression gain was answered most succinctly.
My take on this? RJ probably has all the info I politely asked for. He chooses for some reason to tell me (and all readers) to go find it myself.
'kinda like having access to a beautiful library full of information - but don't know the Dewey Decimal System... 
No problem.
Anyhoo,
Thanks Greg for starting (re-visiting) this subject thread. It never gets old.
Last edited by ToonRboy; 01-31-2008 at 12:20 PM.
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01-31-2008, 12:38 PM
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njzammit: The timing of the 164 24V Super engine.
alfaparticle: Yes, many years ago it was decided that measuring timing with big gap gives a better picture than with the older small gap. Still when the SZ came and Alfa gave timing with both small and big gap, still everybody is using the measuring with the small gap. It makes it possible to compare with other cams in the V6 family. So actually every cam data should be given in both versions. Why not?
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02-01-2008, 07:49 AM
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Richard Jemison
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Join Date: Apr 2005
Location: Pensacola, Fl. U.S.A.
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More cam stuff later.
__________________
Richard Jemison
RJR Racing
http://scuderiagiallo.com
"you don`t have to listen, but you won`t win the argument"!
"Nothing that I might suggest will be legal in California"
Last edited by Alfar7; 02-01-2008 at 07:56 AM.
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02-01-2008, 08:10 AM
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Page 3 of the webcamshafts.com (Web Cams) catalog gives that warranty information. It is for 6 months but there are lots of clauses. One of those cases of not knowing what to expect until you try to return a set...
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02-01-2008, 08:25 AM
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It's not reasonable to expect Richard to convert all the cam information from the various manufacturers into a standard format where they can all be easily compared apples to apples. That would be a massive project, and it would probably take him days. If he went through the trouble to do that it would not make economic sense to post the information here for anyone to use.
Richard has give us the information needed to at least head in the right direction about making cam choices. It's important to understand that cam specs are not standardized which makes comparisons difficult.
Personally, I see a lot of people (not just Alfa enthusiasts) choosing the wrong cams for their engines. This usually results in disappointing street performance.
Here is a quote from Vizard's book "How to Build Horsepower Vol. 1" "Harvey Crane once told me that the most common mistake enthusiasts make is wanting a bigger cam than the engine does." I agree completely.
Greg Gordon,
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