Qv performance cams

WEBCAM spec'd out the original QV/3.2 cams and two performance grinds, one of which they recommend for the street and one for race hp that would probably lose some low end. In all cases (stock and modified), the intake and exhaust cam lift and profiles are the same. The stock numbers actually surprised me. They are close to the numbers in the Bluemel book which lists duration at 020 @ 244

***Also remember that one cannot compare 2v and 4v cam profiles - a little difference in a 4v goes a LONG way***


.................Stock.......Street......Race
total lift-----.306------.324------.348
@
.010---------296-------302-------310
.020---------247-------252-------260
.040---------226-------232-------240
.050---------220-------224------ 235
.100---------194-------200-------208
.150---------168-------174-------184
.200---------138-------146-------160
.300----------36--------64--------90

Stock Ramp is 53; all others 52 (don't know what this means yet).
Don't have a lot of experience, but can tell there is a lot more area under the curtain opening curve with the performance grinds.
Timing is a bit different issue which we can discuss.
Of course, they can mix and match whatever grind you want.

For my requirements for a street car keeping things amazingly simple and cost effective (i.e. carbs, stock rev range and valve springs), I'm not willing in a street car to lose a lot of low end. She feels that with the current carb dyno hp numbers on the 3.2 stock cams, the above street cam installation will put me over 300 hp, and close to 95-100 hp/liter which in a carburetted street use car keeping low end torque is phenomenal - on stock compression and pump gas! Paul Airey also relates that when he put in his P-6 cams, the sound got lower and meaner to boot. Woo hoo. Again, I'm in this for 'engine personality' and reliable fun as opposed to all out dyno numbers.

I have heard some guys (Capo, Kermit, et al) are running 260 qv durations. Kermit Morgan posted on a 260 car he did and said that while it was a screamer, it was difficult on the street.

More as the project develops.

I was wondering how it was progressing!! Do you have the new Cams in now??

Keep Us Informed!!

Important corrections to my previous data after talking to Laurie at WEBCAM today (terrific customer service) – those stack cam specs previously posted are 3.0 QV numbers only! The 3.2 has similar intake and exhaust durations, but a greater intake lift at .343; the exhaust cams are essentially the same in the qv and 328.

So, that changes a lot with performance cam plans for the 3.2, and suggests that dropping 3.2 intake cams in a qv will buy you some lift ( .306 to .343) giving a broader power band.

Since protecting the low end is a priority with me, we've decided to initially keep the stock exhaust cams. This will help keep the low end, and is consistent with what I have previously heard here and on Fchat. We will go for broadening the power band with a more aggressive intake with a .381 lift (up from stock .343) and a duration of 240@ .050 (total 266@ .020) which compares to the stock 328 duration of 224@ .050 (total 244@ .020). These cams will also have the more rounded quick ramp. In an amazingly entertainingly (to me) ironic twist, this performance intake cam uses the same profile for a 1998 Lamborghini Diablo SV.

Price wise, WEBCAM says they will do both intakes for $1100.

Another cam they suggested was a .368 lift with 235@ .050 duration (total 261 @ .020)
She also stated there was a ‘Speis Racing’ specification cam on file with intakes at .360 lift @ 226@ .050 and exhausts at .322 lift with 220 @ .050.

Will post more later, and will try the desktop dyno on the new numbers soon. This is a very similar experience to learning about Webers – great fun and terrific people.

Cams will be going in this summer while I am in Iraq - gotta have something fun to come home to!
Best
Russ

BTW, Russ, I redialed in the Capo cams in that QV for a bit more bottom end (comparitively speaking), and it really improved the drivability. I had set them up for more upper end power at the Client's wishes, then I ended up now with the specs Frank sent as sugested, and I'm pleased with the results. Frank does knows his ****!
One thing I like about the Ferrari V-8 is it responds very well to cam changes due to the Rod stroke ratio being almost 2 to 1.Even 2 valve carb cams can easily be set to make more top end power with a bit of patience, and somewhat tedious work.

For those interested in researching different performance cam options, here's the summary of my personal data experience so far:

The Elgin and Webcam measured specs on the stock 3.2 cams match almost exactly (intake: .344 lift with 222@ .050. 244@ .020). Interestingly, in 3.0 qv cars, the intake and exhaust cams are almost exactly the same as the 3,2 intake durations, but with much reduced lift at .306. Also, the stock 3.2 cams match the stock Testarossa cam profiles almost exactly. I have the stock profiles with lift/duration numbers if anyone is interested.

For my specific application, have chosen to just swap the intake cams and not sacrifice as much low end shooting for 95hp+/liter from a Weber 40DCNF retrofitted 3.2 QV with maximum reliability on street gas and DIY enjoyment.

Dema Elgin had initially recommended going to his intake grind of (.364 total lift with 238@ 050 and 257@ 020).

Laurie at Web has 2 recommendations: a Lamborghini Diablo profile of (.381 total lift with 240@ 050 and 266@ 020) or another of (.368 total lift at 235 @ 050 and 261 @ 020). She also stated there was a ‘Speis Racing’ specification cam on file with intakes at .360 lift @ 226@ .050 and exhausts at .322 lift with 220 @ .050. Again, I have the whole profiles if anyone is interested.

I know that Paul Sloan's wild Weber 48 IDA 3.0 QV project has more aggressive cams still, and projects to 350 hp+; and absolutely ranks as one of if not the most spectacular looking 3 liter engines ever seen for sure.

Would like to compare to the fabled Capo cams, but will have to go look as I've misplaced them. I do remember them as being indeed quite aggressive.

Stock QV head flow measured:
Lift -- corrected cfm flow
0.10 -- 31.6
0.15 -- 51.5
0.20 -- 64.7
0.25 -- 80
0.30 -- 86
0.35 -- 89.2
0.40 -- 92.2
0.45 -- 94.2

If what the posted Durable1 flow bench says is true, and it is somewhat corraborated by others, I would not gain much from going to the .381 lift over the .360's lift as the qv heads are the restriction, no? Could look at keeping the stock valve springs at this lift level.

Anyway - this all represents a lot of research that I'd thought I would put here in case anyone is interested.
best
rt

here is the side-by-side of what I have:

Stock 3.0 QV vs stock 3.2 intake cam

Max lift 3.0 QV: .305 ; 3.2 QV: .348

Lift.......3.0QV........3.2
.010......296..........284
.020......247..........245
.050......220..........222
.080......203..........208
.100......194..........200
.150......168..........178
.200......138..........152
.250......100..........124
.300.......36............84

Laurie emphasized that with a 4v engine, even a few degrees made a large difference - much larger than it would with a 2v. You can see with the increased lift, the valve opens into the effective range sooner and stays there longer. This is what I would like to try to achieve in my car as well getting a fast ramp to allow a larger area under the curve. I'm deducing that with the stock head, I should keep the stock springs as monster lift cams are not as effective without porting.

And now, for a more spectacular comparison! For those of you who always knew the 2v cams got tamer with FI, but not just how much, here is a side-by-side of a set of Euro carb intakes with a set of later Kjet cams:

308 carb total lift: .349 '82 Bosch FI total lift: .305

Lift.......2v FI........2v carb
.010......288..........310
.020......242..........260
.040......222..........240
.050......216..........234
.080......202..........218
.100......192..........208
.150......166..........184
.200......136..........160
.250.......98...........130
.300.......28............92

Wow, huh?
So, if nothing else, we've quantified what we've always heard and boy, is it true!

An interesting twist: The 3.2 FI and euro carb exhaust cams have the same profiles and lift, except of course that the 3.2 is a 4v. To keep things 'Ferrari spec' as it were, wonder if one could fit the euro carb 2v profile on a 4v cam - it actually matches up closely with some of the other performance cam numbers.


I also got the Capo QV performance cam with timing as well. While I do not have the full profile, it has 254 duration or so. Again, small degree changes seem to make a huge difference.

So, as a summary chart, here are the stock vs. performance choices so far:

Lift......QV(.305)..3.2(.348)..Carb(.349)...Elgin( .364)…Web(.368)…Diab(.381)
.010......296..........284……...310
.020......247..........245……...260……...……257………….. ...261……..…..266
.050......220..........222……...240………...... 238……..……..235…….…...240
.080......203..........208….…..218
.100......194..........200….…..208
.150......168..........178……...184
.200......138..........152….…..160
.250......100..........124……...130
.300.......36............84…….…92


Hope this is interesting for some.
best
rt

Hey Russ,
How much lift can you add before the stock springs go into coil bind? Also, any clearance problems with the top of the valve guide/seal? Just thinking out loud! Bob

Hi Bob,

Not trying to answer for Russ, but 9MM Lift was the general standard for several decades.

JRV, you confusing an old guy. 9mm would be what? Lift at the valve or max lift for the springs. Looks like Russ is adding about
0.042"lift which is not very much, but wanted to made sure he has the clearance on the coils to do so. Hate to see a spring break due to coil bind.
It gets kinda messy when that happens

First let me say I'll always defer to JRV on anything technical!

As I understand it, the qv heads start flowing well at about .15 to .2 and approach max flow in the .333 lift range. What I've learned is that the really important thing is the 'area under the lift duration curve' in combination with event timing for determining the amount of air that enters the cylinder. Thereby, although going to a .381 lift is not a great an absolute increase, the valve ramps faster and stays in the maximum flow lift range for a longer duration (area under the curve). In addition to more high end power, this increase in lift gives power across the power band. Increased duration and event timing tend to move power up the rpm band. Although not verified, I understand the stock springs become limited around .400 lift.
Other's opinions welcome here!!
Best to all
rt