Recieved timing recommendations from Webcam on the new intakes for the 3 people still following this: "Since the engine will have carburetors then I would recommend around 105° lobe center on the intake, and around 105° to 107° lobe center on the exhaust. The tighter you put the lobe centers the more piston to valve clearance issues may occur. Minimum clearance for piston to valve is .050 on the intake and .080 on the exhaust." Should be interesting. Fishin' in the Tigris River, rt
Quite true my friend. As usual Laurie has it pretty well figured out. Good thing that you have a 4 valve, as they are a lot more forgiving on the valve interferance on the overlap portion. As I recall, with th 2 valve, you must be very cautious in having over .100" @TDC, especially if oversize(1mm limit is wise) valves are used. The 4 valve is much more forgiving in that area. Your lift and duration figures look good to me, with the rest of the motor in it's current shape a far as compression,porting, etc, go. It will probably not be a "peaky" set up IMO. Sure, it would be nice to have more compresssion, but where does it end, LOL. If it does provide the HP numbers that the desk top says, you should end up with a fine ride. I found I had gotten very fond of Randy's Mondy after it got a few more horses under the hood. A very underated car I think. Take care! Kermit
Cams arrived from Laurie at Webcam - they were hard welded with the new profiles over two QV intake cores. Norwood's will be installing and setting timing by dialing in next week (around 105° lobe center on the intake, and around 105° to 107° lobe center on the exhaust) and then off to the dyno for tuning. Should be interesting. I hope this works. best rt Image Unavailable, Please Login Image Unavailable, Please Login
Was talking to someone else about actual event timing of the new cams. My math may not be good, but at .050, I think that puts intake opening at 12 btdc and closing at 42 abdc. Likewise at .050, exhaust opens at 38 bbdc and 12 atdc. The comparable numbers at 020 are intake opening at about 25 before tdc and closing at 55 abdc, or 261 total duration. Exhaust will be near opening at 50 bbdc and closing at 24 atdc (pretty close to stock). Just to review the stock settings at 020: intake - 16 btdc to 48 atdc (244) exhaust - 54 bbdc to 28 atdc (244) overlap 26 degrees. A new overlap of 49 degrees - whew! That's something on a 4v up from 26 if my math is right. I'm thinkin' bigger idle jets.... So, we are adding about 13 degrees intake duraton at 050, 17 degrees at 020 with an increased total lift. Not much in a 2v, but I am told that 4v really respond to smaller changes. I hope this works. All advice/opinions appreciated - dyno in about 3 weeks best rt
Hey Mark - if these new cams work out, I'll have a spare set of 3.2 intake cams which are higher lift that your 3.0 qv's... Then again, Dema Elgin never returned my qv cores they screwed up and never responded to my inquiries of what happened.... You might can have those for free. Cams going in this week. Next big project is a set of headers to match the cams - any ideas here? Pics and dyno hopefully in a week or so...
Russ - my dad was reading thru this thread and sent me the following to post to your attention: "Dear Russ, The heat and the sand must be getting to you. Why all this tinkering around with such small cam timing changes??? My Mondial has an intake duration of 308 and an overlap of 98, and that was stock. Just remember to sit on your flak jacket in the helo rides. Best regards, Robert"
Yes - the heat and sand are geting to me! Tell him I've been reminded that political mess doesn't get better in a war zone, it gets worse! And now it's Joint! Please give our favorite Flag Officer my best, and tell him since I have two more valves per cylinder, he can multiply my overlap by a function of 2. Looking forward to seeing all of your family and the 'other Mondial' on my return. best Russ
Error Alert!!!!!!!!!!!!! I double checked my math and made an error on the exhaust numbers: will be closing 17 atdc and 47 bbdc, with a real overlap of 42!! I've tried to make a graph, with the stock intake numbers in green. best Russ 'Math in public impaired' Image Unavailable, Please Login
Well, it's been two years and two cam regriders in the process, but the new high lift longer duration intake cams from WEBCAM are in. The cam timing was set and dialed in using a degree wheel. It's hard to believe it's finally happening. Many thanks to James and Mike at Norwood's. More soon. Should have a dyno in a week or so. I hope this works. best to all rt Image Unavailable, Please Login
Thanks Philip May require larger idle jets (57 or 60?) to cover lower idle vacuum signal, but it's already quite rich on transition circuit running 53's. It is probably pretty close, but may add a smaller air corrector (now 190) for richness at high rpm. Will stick with F24s and keep the 140 mains, but have 145s. I'm anticipating that the ignition advance will stay about 33-34 at 3200 or so. I've never heard of cams affecting advance before. When I asked this question elsewhere, we got a terrific response from Mitch Alsup: "Only on cars that were seriously under-carbureted before the cam swap (in addition to a carb upgrade). The issue is cylinder pressure, and the critical region is between 2500 RPMs and 4000 RPMs. At RPMs less than 2500 the engine is not up the TQ curve far enough to build big clinder pressures; at RPMs above 4000 RPMs, there is enough cyclinder turbulance to mitigate the cylinder pressure issues. Note also that 4000 is generally where the advance stops advancing and turbulance is the reason it can quit. In your case, the engine was never undercarbureted. However, during final tuning, you might try making the advance less steep between 2900-3300 with the same initial ramp and same final total advance. This can be used to decrease the octane appetite of the engine without hurting the top end in any way." Thanks Mitch as always for your terrific input. And of course we'll keep the opened up airbox, K&N, short stacks and flow through muffler with Ansa resonators. Philip said his P6 cams made his engine sound a lower tone. This could be good. Hope this works. best to all Russ Maverick Medic of Mesopotamia
Cams being timed tomorrow by dialing in - enough room on the Mondial to do it in the car as there is a lot of space. I am interested a bit about such a large overlap (42) for a 4 valve. I know the FI qv's and 5v's all have overlap from about 26 to 30 or so. I am not sure what to expect quantitatively from larger overlap with a much earlier intake valve opening at around 25. I do understand somewhat the effect of the later intake closing on the high end a little better. For comparison 2v overlaps are much higher. I'm told these new intake cam specs are not too radical even for a qv, and it should feel a difference without too much torque loss down low. All comments welcome. Dyno the end of the week I'm told. best rt
Copied from another board, a very good explanation of opening events from Mitch, and referencing the cams the Mondial is having installed: "In general, I am a fan of rather even overlap periods balanced between intake and exhaust. {In days gone by, I used to have a street FIAT X1/9 with 2 DCNF 36 Webers (32mm venturies) and 35/75+75/35 cam with 4:1 headers.} If you can find a good tune, 70 degrees of overlap is streetable, especially if 'you' respect the throttle in the low RPM band. 42 degrees is not 'that agressive'. This would put the intake opening timing near 21d BTDC and the exhaust closing at 21d ATDC. The 25 degree number from the cam grinder is trying to get the header resonance setup earlier in the RPM band, possibly to ameliorate the loss from the low end. As you add overlap, you are leaning upon the tune of the headers, and if the headers are tuned for a reasonable RPM band than a lot of power will show up from mid range through top end, at some moderate expense to the low end. Since you are most likely going to continue to use the same headers, the earlier exhaust opening will have the negative pressure wave arrive earlier and find the intake valve already opening so the power band starts earlier. The power band will be wider because the exhaust valve closes later giving the negative pressure wave time to arrive even at high RPMs. I might note that Ducati motorcycle engines operate with about 45degrees of overlap and very agressive cam actuation at similar RPM limits as the 355 engine. The potential problem with large overlap is when the positive pressure wave that follows the negative pressure wave arrives while the exhaust valve is still open. Ths pushes burned exhaust gasses into the cylinder and up the intake. Highly tuned motorcycle engines have big problems in the 3000-3,500 RPM range do to this anti-resonance effect. Some motorcycles engines and the F355 in particular solve this issue with muffler valve after the headers to strangle the wave effects from the headers until the affected RPM band is passed. The F355 exhaust management unit opens the muffler valve above 3500 RPMs." Again, many thanks to Mitch Alsup.
Cams being dialed in - got this note from James while I am now in Germany trying to hop home. "Intakes: installed at 105 (104.5 for 1-4 and 105.0 for 5-8, close as they get) lobe centers just as cam card specifies - no problem. Exhaust: Installed on the marks at 112 (111 for 1-4 and 111 for 5-8, close as they get) lobe centers which is factory spec for 3.2 liter motors, this is where they where when we pulled them out. The Web-cam cam card calls for a 107 lobe center which is very close to the 3.0 liter US emissions spec. (106 actually) but I don't believe any of the 3.2 liter motors ran this lobe center. The 111 lobe center is where I would recommend them be installed at but was not sure if you and Web-cam decided it would be better to retard the exhaust a few degrees." Any ideas or comments? best rt
Dialing in in the cams with a dial gauge. Image Unavailable, Please Login Image Unavailable, Please Login
Note today from Norwoods: "Glad your back! The cams are all timed up, 111 on the exhaust as before which was fine with Web-cam. Ken should have the valve covers on and running before the end of day tomorrow. With the new ride height will have the alignment checked and then get some road miles and dyno time on it. If I don't hit any snags you can come get it next weekend. Give us a call when you want. James" So here is the summary: intake cams (Webcam): total lift .361; durations 261@020, 235@050, lobe center 105 exhaust cams (stock 3.2): total lift .305; durations 244@020, 222@050, lobe center 111 Cam changes I am told are much more pronounced in a 4 valve than a 2 valve. For those of you who may be just joining, this is on a 3.2 liter qv with 4 x Weber 40 DCNF, 34mm chokes, 9.2:1 compression (stock US). The new ride height he is referring to are the new stiffer springs with adjustable spring perch comp Konis that will slightly lower the ride height and sharpen response. Although probably not accurate, I plugged the new changes into my desktop dyno normalized for best recorded output previously actually dyno'd, and came up with 309 hp at the flywheel (up from approximate avg of 280+ with stock 3.2 cams and Webers). We'll see. More soon! best rt
Cams are in, car started today! Drive around tomorrow and align new lowered suspension with stiffer springs, dyno tune on Thursday!!! Norwood's rocks!
Found this great thread tooling around with a great post with incredible data on what happens when you vary timing on two valve injected engines, suggesting how to have a better performance from a hotter cam with 2 valve K-jetronic : http://ferrarichat.com/forum/showthread.php?t=3023&highlight=355+cam+overlap
How was the timing wheel mounted to the crank? What is the wrench that's turning the crank attached to?
I think this degree wheel fits on top of a precision socket and extension to turn the crank. I'll try to get a picture next week when I pick up the car. Here is the manufacturer: B&B Performance Products 693 Cross Street Lakewood, NJ. 08701 Phone ( 732 ) 364- 6700 Contact B&B Performance @ [email protected] James will be dynoing the car today! Hope this works. best rt
With 308 airbox/K&N and resonated quiet muffler, the new cams pulled about 241 SAE rwhp and 202 ft-lbs of torque, translating into about 290 hp and 243 ft-lbs of torque at the flywheel. Without the airbox with open trumpets the dyno showed about 10 hp more. for comparison: stock 3.2 US: 260 hp with 213 ft-lbs torque stock US Mondial t: 300 hp with 229 ft-lbs torque The torque really surprised me; I may open the exhaust back up some, but for a daily on the street I think 290/243 is a great result for 3.2 with 9.2 compression. Hope to get a graph soon. best rt
Not to shabby at all Russ! Glad to hear you have the baby running again and will have the time to enjoy it now. 290 isnt to damn bad at all out of a 3.2 with the compression ratio you have, I am going to attempt mine this winter when I drop my engine so I am happy to see the nice gains you got as everyone could use a little extra hp and especially that torque you magically pulled out!
Here are the documented numbers from Norwood: Max rear wheel hp was 240.2 with torque at 203.4; so still about 290/240+ at the flywheel. Also attached is another run where the max hp was 239, but the max torque was a whopping 213 ft lbs, or approximately 256 ft-lbs at the flywheel - wow, huh? Check out the Air/Fuel ratios - these Webers are doing pretty well with delivery in the 13s for best power in the second, and a bit richer with the better torque. It's so close, I do not think I will play with it, other than to try a set of 36mm venturis for the heck of it. Since my car is primarily on the street, that torque is very good. Thanks to James and Mike at Norwoods - those guys are the best! rt Image Unavailable, Please Login Image Unavailable, Please Login
