I'm just curious to see if anyone is changing lift or is just duration and ramps that are being changed. Also Is anyone testing their heads on a flow bench, before they decide on their cams?
If you search past threads apparently there is a lot of flow to be gained increasing lift up to 10.5 mm on 2v. That is the way to go besides duration.
Quick question.............. On my 77 308 am I better trying to find P6 cams, Euro cams or have mine reprofiled? I am currently runnning single distributor, MSD, K@N and a tubi. No air pump. Car runs really well (other than the tach way too high). I am looking for more power and torgue across the whole range if possible. I have already got the bigger jets have just been too lazy to install so will report on any difference. Thanks,
Is anyone having piston to valve clearance problems with these "mildly" improved cams, how about the P-6 cams and stock 8.8 pistons?? I know that the increased CR really helps, but if you can install the p6s without having to do a complete overhaul... that would be nice. 77 flowmaster exhaust, K&N, one step up in jets, dual MSD,soon to be dual crane ign. just a thought, chris
This is my concern on the 348 as well but I know the the 355 runs a larger duration and is essentially the same block underneath so I think it should not be a problem. At the same time this is a new area for me so I am looking for some help from more knowledgeable folks on here in regards to the 4v 348 engine. SB Chevy no problem...Ferrari I am not to positive and dont want to make a big $$ mistake.
Russ - How similar to your cams are the 348? My guess is they have to be damn close but I figure if your guy can also grind me a set of 348 cams with a 255-260 duration as well on the intake. That should still give me 90% of the intake flow on the exhaust with the stock cam given the valve sizes. Any help is appreciated as always. John
John Yes, we are in similar boats. Webcam is mailing me some prospective grinds. On the intake side, a stock 3.2 is about 244 @020 with like about .303 lift, best I can remember of the top of my head. Now, here's where we have to make compromises. Since my car is primarily a street car, I do not want to loose a lot down low (torque) to have an 8000 rpm screamer that will not see as much use, but looks great on a dyno. So, in addition to bringing in more lift (good across the board) will only look at extending the duration 8 to 10 for about 255 or so. Laurie says that with efficient 4 cam engines, little cam changes make a big difference. The ramp will also be rapid, so more effect faster. She felt pretty confident that it would be a very tangible seat of pants difference, bringing the engine up to about 300 - 310 usable hp keeping a good low end and a streetable powerband. Pretty good remembering the stock 3.2 was 260 hp out of the box. In addition, the maintenance will be much more DIY friendly, a major part of the goal. While a bit harder to quantify, the personality of the engine is important to me, so I am dialling certain cammy characteristics I find entertaining. With your EFI, I'm sure the 255 - 260 durations would be easy - just remember the more radical, you'll loose a bit down low for gains up high. I do have a good warm fuzzy about Laurie and the Webcam gang after having a really heinous, disappointing and costly experience with another well known vendor. When the options come in next week, I'll post them here for folks that are interested (I'm guessing 3 or 4 of us ) to take a look. best, and good luck! Russ "Not four liters, but lots of bolt on fun!"
Cool, I'll be looking for it! I'm pretty sure I could use a little more cam in the QV too, it just doesn't quite have the top end pull I think it should
Why would a 4v performance cam characteristic be (reportedly) so different from a 2v. Fundamentally cam timing is all above scavenging optimization at different RPM levels (isn't it?). I don't know why a 290 degree 100 degree overlap 2v cam wouldn't be sauce for a 4v motor too. Oh, Mark, on your other post on rotating Triumph cylinder heads, IIRC it was done on drag bikes where they'd try to get some ram air into the Amals. Philip
The key to a 4v engine is that it exposes more valve are faster than a 2v, and generally flows more too. It just doesn't take as long to fill the cylinder when you're feeding it with 4 valves. That lets a 4v run a milder cam with less overlap at any given rpm than a 2v would need. For the street, less overlap means lower emission. At the track, you can rev a 4v higher without beating the snot out of the valves train with huge lift and steep lobes. I used to ride a pro hillclimb bikes and that is where I saw the Triumph, head on backwards, carbs on the exhaust port. It was fast, but no real numbers...we get times but they don't mean anything like a 1/4 mile time would.
Russ - I cant wait to hear how you make out with the grinds that Webcam is sending you as I would love to get a set ground up for me soon as well. If things look good let me know and I will get in touch with them and see what they can make me as well. Hell I am wondering if a direct copy of the cams you run wouldnt be damn close to whats in the 348. I have never compared so I am not sure. As I talked about in another thread here I talked a an engine builder in the twin cities today who said that porting the heads wont buy me anything on the 348 as they said the 328 he did only made 8 more hp at the wheels. He also thinks that caming the thing with 260 duration intake and stock exhuast cam (the 328 he built) would lead to at least 310hp out of the engine which is really damn good for the 3.2 in his mind. So if this is any validation to your theory you can sleep more comfortable tonight. If I could get the same bump I would be happy running a 260 duration to keep the street torque but also get some more high RPM ponies. Have you done any calculations on torque in the mid rpm band? I am most curious here as well as from the SB chevy's I have the mid range grunt really helps you pull out of corners when your stuck between gears. Any thoughts as well on how much extra lift you are going to run and will the springs be able to take it for an extended period of time. Bumping duration will do nothing to them in my opinion but the lift sure as hell will in terms of wear. pma1010 I cant imagine a 290 duration cam on a 4v! Would be a nightmare on the street. A friend has a 280 Supra and the damn thing has nothing till the turbo hits and RPM's are around 4k.
Also Russ and Mike what sort of fuel injectors do you think the new cams will need? I am thinking at least 45-55lbs/hr to meet the demand but I am not sure what the stock units flow in the 348. I just want the EFI to keep up.
I think probably to a bit over .4 or so - will post what Webcam thinks next week. This is in line with previous posts by Kermit that the 4v head flow peaks at about .4 lift. Would like to keep stock springs if possible. as far as fuel delivery - would go with what Mark recommends as it is beyond my technology. If you ask me, as a starting point I'd say 36mm venturis/145 mains/F24/190 with 55 or 60 idles due to a reduced vacuum signal.... best rt
Sorry for the slow response guys was away for a few days. First off Mark you are completely right on the injector sizes. I dont know why the hell my math was so off. I was using the same formula as you but coming up way off. I am wondering still what the stock injectors flow and as they are low impedance they are a little bit more of a pain to find with companies like Accel etc. After rerunning my calculations here I shouldnt need over a 33lb/hr injector all the way up to 400+ hp and that size should also ensure I dont have to much flow at idle. Russ I talked with Kermit a little today about your cams and needless to say am even more excited to have you get your specs back from WebCam as I really want to see what they come up with. I am thinking no more than .410 on lift after talking with Kermit and then after dicking around with some numbers dont want to go over 260 on the intake while leaving the exhaust the same. Assuming everything else in the engine remains the same desk top dyno thinks 350 should be doable on the low end so if thats true I will be happy. Let us know as soon as you get those grinds!
Rob at http://www.force-efi.com/ probably has or can find you injectors and his prices are pretty good....it seems like 30 and 36 are standard sizes. There is a company RC http://www.rceng.com/ that can test your injectors (I would just send 1) and tell you what size it is. They can also sell you any size you want, but I think they are a bit pricey.
Mark I used RC's injectors (560s) in a prior car. It is worth making sure they all flow uniformly if there's uncertainty - so, my advice would be to send all of them. Philip
Philip I think he just wants to know what size the stock injectors are so he know's if they are large enough to handle any added hp, I don't think he suspects a problem with them. That's why I thought sending 1 would do.
Your right Mark I really just wanted to find out the size of the injectors so I know if they will flow enough for the added hp. I know I could just bump the fuel pressure (I believe the current pressure regulator is replaceable with an adjustable early 80's VW bosch part 0280160001) but wanted to change injectors possibly to get more flow and a better spray pattern as the stock bosch units I have been told leave something to be desired after 30k miles. I talked to Summit and they are fairly positive that Accel produces a low voltage 30lb/hr injector but were going to check for me. Thanks for all the help again guys and I look forward to hearing from you Russ about what WebCam says.
JJ--just for info I have 19 lb injectors on a 328--perfect match ALSO--throwning a curve in here for all to see---v-12 cams thinking about getting my 330 cams re-profiled--I know Elgin has done some and looks like Web has too.... Who has experience with v-12's here and had this done. What profiles did you use? Did Web or Elgin come up with it or you? What was the cost and was it worthwhile???
Have returned from DC to find the anxiously expected letter from Laurie at Webcam. They spec'd out the original QV/3.2 cams (cool!) which I will post here for all posterity, and two performance grinds, one of which she recommends 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 when I wake up. 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, another FChat hero of mine, 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 rocket kick ass high rpm screramer, it had little bottom end and was a handful on the street. This is great info, and would recommend bookmarking (and donating to my FChat subscription and beer fund ... just kidding). All discussion welcome. Good nite, all rt
I have had quite a much better experience with the WEBCAM folks. They do already have some V-12 profiles as well. Will post more on cam cost later. I think it will be less than going to 4 liters. Will run the lift duration numbers on the ol' cheapo desktop dyno and compare. best rt
Russ you are the man! While you are just returning from a trip I am headed to NC but reading my favorite website at the airport brought a smile to my face. I am curious how easily they could get me a profile on the damn 348 cams I know they are not much different from the 3.2/QV ones but you never know what oddness lurks in a Ferrari. I am really interested to see the duration numbers you crank out of desktop dyno as the lift was lower than I expected they would come back with for the race cam. I cant see how that grind would cause you to lose a lot of low end compared with the "street" grind. I would estimate if anything it has to be less than 5-10hp which I dont know it it would be noticable. Anyway when I get to NC and out of O'hare I will write a little more as I have some other questions on them as well. If WebCam estimates 300hp I have to believe it as they are damn good at being close with their estimates. Now you have me thinking my 360 hp goal is reachable....damn you damn you for making me invest more money in that lovable red piggy bank! Talk to you soon.
