So how close is that to an 11% increae in hp? While perhaps not so much a player in a supercharged EFI engine, are there any velocity issues for a N/A carb engine? An 11% gain in hp would put me right at 320 hp, or 100 hp per liter, which seems pretty good to me.
Russ, In theory it should be a 1:1 gain, provided the engine needs the air. In this case it does need to the air, but reality can still vary from theory....I'll see what Vic has for data. Other factor can come into play to in that the carb or air box can still be a restriction. An 11% gain at the head may only be 5% once say the air box is added. Fixing the air box is then the next step. You can find all that on the flow bench though and that is why unlike may shops, Vic will ONLY port heads with the matching intake sytem and headers....there is no other way he can promise results and actually deliver on the promise. I've known Vic for nearly 20 years and to the best of my knowledge, no engine has even left the shop not making the hp/torque he promised. This 11% number is an increase in but flow and velocity, because diameters have not been changed so it's good on any engine. Increasing the valve and port area will always help flow, but if the flow the flow does not go up by the same % the port/valve area go up then velocity will drop and low end along with it. That's not going to happen here. The engine can easily use a 31-32mm valve and the modern Japanese cars with similar bore/stroke are doing just that. Going to a 32mm valve is about a 20% increase in area, but the flow will be up at least 30%, so again there will be both more flow and more velocity, so hp/torque will go up at all RPMs, not just on top. If I were building a race engine Id be looking at 34-36mm valves, but Im not, so Im not. This is strictly street port job designed to work with stock redline and deliver more hp/torque from idle to redline.
yeah...I was hoping to find a near drop in for cost reasons, like the 348 valves, but it looks like they are still a bit tooo small. Custom it is I guess.
So will the 32mm valve give the correct Intake/Exhaust flow ratios, or just peak flow? How much do 16 custom valves cost, anyway? Also, I would like a broad flat power band instead of a narrow but high peak - would the stock intake, the 348 or custom 32mm be best - or is it more a function of cam? Very cool discussion.
It looks like Ill be getting custom intake valves made. I dont have the pricing yet, but they are always cheaper in quantities so, any other QV/328 owners thinking about porting, now would be a good time to order your valves. Think about it, Ill post the prices and quantity breaks when I get them.
You know....I have not spoken a single word to Vic about the exhausts. I know the ports are PLENTY big, but I don't know about the valves...they are pretty small compared to the port. The flows will be matched when it's all done, but I don't know what will be required on the exhaust side. I'll look into it. Picking the right valve is more about redline than anything else. The engine needs to flow more air the faster it spins so you need to set the flow to fill the cylinder up top. An efficient port with good velocity will also work well down low giving a nice wide, flat torque curve - a flat torque curve indicates the cylinder fill is the same acroos the flat region BTW. I would expect to see the entire torque curve shift up 10-15% and then not be dropping like a rock at 7000, but pulling right to redline. It will be better in every way. Vic says he has some numbers for you and will be shooting you an email. Basically he doesn't see any problem making your HP/torque goals. I don't know what he's planning for you though, it will be in the email I'm sure.
Here the start of the new intake....doesn't look like much just yet. The parts are going for a test run on the flow bench before I do any welding. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Way cool!! That looks great! Can I get you to make me some velocity stacks and airboxes? How about a crossflow manifold that uses sidedraft Weber DCOEs?
Haven't got the email yet, but he did say earlier that it would take a couple of weeks. I am quite happy with the range of the torque power band and 10 - 15% more would be great - that would be about 233 ft-lbs at the wheels or 280+ ft-lbs at the flywheel - 280 ft-lbs in a carb'd 3.2 liter - woo hoo! And not to mention 276 hp at the wheels or 332 hp at the flywheel if Vic delivers the full 15%. Even at 10%, that would be 269 ft-lbs and 318 hp -that would be one amazing naturally aspirated Mondial. As a comparison, both the Mondial t/348 put out 238 ft-lbs and 295 hp and gave 6 sec and sub-6 sec 0-60 times. It's almost unbelievable. Has he flowed your head wth any changes? If so, what? I hope this all works.
No need to hope, it always works out because sometimes math/physics are your freinds. If it flows the air it has to make the hp/torque, it just has to. I'm sending the new maniflod (parts) today and Vic is tracking down larger valves to play with, there may be more news by the weekend. Basicaly though, the intake valves are a bit too small for the size of the port and are the flow restriction. I'm not sure yet if the seats will need to be changed, but I don't think so, just the valves and the seats re-cut.
The latest word is that the head just loves it's new big valves, still with stock size ports, so velocity just keeps going up...to the point of puting the flow of the new runners as the limiting factor....I may be making some bigger ones. Hopefully I'll have numbers tonight, Vic was still playing with the runners at the transion from the runner to the mounting flange....something wierd is going on there.
Very cool. These are just the intakes that are larger? Which size did he settle on? Intake/Exhaust ratios done yet? Looking forward to the numbers!
With a 30.5mm (348) valve, the port cleaned up a bit, and the new intake design the flow is: lift flow %change .100 - 40 +64% .200 - 87 +24% .300 - 101 +15% The numbers down low are actually a couple cfm higher with the intake than without, so thats good. This translates to about a 25% flow (and velocity) increase when you look at total area under the valve lift curve, so it's pretty good....but it's still short of what I think can be done. Vic is going to try a 32mm valve in the next day or 2, I'll post those numbers when I have them. Then we'll make the final call on what the set-up should be and do it on the realy heads and manifold. Vic hasn't touched the exhasut yet, he wants to know what number he needs to match first. He feels about the same way I felt, the exhasut port is PLENTY big as is. After the intake is set, he'll seen what is required, if anything to get it to match, just radiusing the seat may be all it needs, or it may need a slightly larger valve, but the valve and seat the the only hold-up on the exhaust side. Russ, Basically it's looking pretty good. Unless your carbs are acting like corks on top of the runners, you'll make the numbers you were after with decent gains from idle to redline....and it will pull right to redline now, no more giving up at 6800. Vic is still working on an email and quote for you, but wanted to finish up the testing and get all the part prices first. Basically he said that you're dyno curve matches his software within 1% and 100 rpm right across the board. The flow curve he has right now makes him feel pretty good about promising you 250 rwhp (if I was listening right), and the ports not done, flow is still on it's way up. One thing to note is that the next step after porting would be higher lift cams. Going to .400" lift adds about 10% more flow and .450 something like 12%....so there is 10-12% more hp just sitting on the table........ Wil, Vic has been working on the 4v heads and has not started the 2v head you sent. He made the valve lift fixture and is set-up and ready to go when he's done with the 4v port. His first impression is that the port is terrible. The second thought is that whatever he does, the higher lift cam you put in, the better it will work. As a reference, my XR h-d engine is about the same bore, stroke and valve sizes and likes .580" lift....and makes 125 hp/liter. 0.300" lift is nowhere near enough. Porting will make it a lot better, I'd think a 20+% gain is probable, but it will need proper cams along with the porting to get the big hp numbers......or a blower in you case
I forgot to mention, this is now the highest velocity head Vic has ever had on his flow bench. That means good power increases at all rpms, but it also means that to increase the flow further, the port cross-sectional area will need to go up. When he puts in the larger valve, he will play with the port size to see what he can do increase flow and without decreasing the outstanding velocity it has now. It may mean sticking with the small port/valve, but normally things scale pretty well and the engine really could still use another 10-20 cfm so the bigger valve looks like the way to go. That will make it really good with stock cams and even better high higher lift cams. Right now Vic thinks the naturally aspirated hp for my engine would be about 320-325 and with stock cams and compression and with higher compression and higher lift cams it would easily be over 350 at stock redline. Using the 320 number, I'm still going to need aqbout 20 pis boost to hit 700 hp....I'd like to see the base number closer to the 350 mark so I can make 700 with 15 psi
While it may not be comparable, assming both of our inductions could keep up with the head flows, your would be showing at 320 about a 33% increase over the stock factory flywheel hp rating of about 240, which is almost unbelievable. Even with discounting my current higher lift cams and slightly higher compression than yours (9.2 vs 8.8) that same increase (again assuming the carbs could keep up, which I feel pretty certain they would at either 34mm or 36mm venturis) that same 33% applied to my stock rating of 260 hp would work out to 346 (!!) flywheel hp, or about 287 rwhp (!) at the wheels and perhaps as much as 221 ft-lbs (!!!) of torque at the wheels from 266 ft-lbs (!!) at the flywheel - from a carburreted 3.2 liter engine. Equally astonishing. If this works I am going to have to change my drop gears ratio or final drive ratio.. OBTW - the target is 265 or more rwhp (gain of at least 15) with same or better low-end to meet cost effectiveness. From your numbers, that should be hopefully easy.
33% works out just about right. Pulling the CIS is 10+% and now the flow is up another 25% over that....it sounds like 33% is conservative to me. I want to the peak volumetric efficiency should be at least 110% on a good street motor and 125% is reasonable. The stock number is 85% or so, pretty low by today's standards. Ferrari like all car builders was really struggling to meet the emissions regs back then and did a lot of things they probably wish they didn't have to to make it happen. I know on the street XR h-d I bought, the heads came ported, but to flow no more than 110 cfm and it was the most powerful street bike hd ever sold at 70 hp. The first thing to do once you got it was send the heads back and they would re-flow them to 138cfm and it became a 90hp engine, 100 with cams. Almost a 50% increase on what was already their best engine ever. Same thing here. It looks like ferrari did a pretty good job on the head design, then choked it down until it would meet emissions. The intake valves are just too small. 32mm will be the ticket for street use I'm pretty sure....just like honda puts in their 1.6 liter 4 cyl.
Have you considered adding a supercharger? - ok it's a shamless plug for the one I'm selling. http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=270075030372
After reading the nearby clutch thread, I think the porting to max normally aspirated hp, probably 320 - 350 flywheel hp is the way to go without beginning to change a lot of other components (clutch, etc..). That will put most cars around the 10 lbs per hp range (even the Mondial) with solid reliability not overstressing any other components - I think a great balance of power, tractability, simplicity, reliability and mechanical elegance. Then there is that magic 100 hp per liter thing. Even the Mondial will be down in the low 6's high 5's on 0-60mph with that much power. If this works, this could be an amazing thing for unblown cars to put out 320 - 350 hp. I'm in. Now should I put in those 3.54 liter pistons/liners.... Clive - I think you should do one of each - one supercharged with Mark's kit and one naturally aspirated 320 hp ported and polished 3 liter car. Wow.
Mark, Thank you for relaying that message. I was just wondering if Vic ever received the second cracked 2V head and valves I sent. He was wondering how stock my ports were so I sent him a similar head from an injected 2V engine I had lying around to compare. I was about to send him an e-mail anyway so I'll still do that. I'm very interested to see what Vic comes up with. At some point I may have to give him one of my billet intake manifolds to get true figures. I'm not rushing him at all. I'm in the same position with my "owner" as you are. Just kidding, she's been very supportive but I did drop a bundle on that car in a big hurry. I just need to take a little break with the check book. Still want to do that CF rear deck lid too. Wil
If you are going to do the 3.54 liter conversion, you best decide now. This might seem obvious, but a 3.54 liter needs more air than a 3.2 liter at the same rpm. With stock redline a 3.0 can use about 110-120 cfm (@ 10" h2o), a 3.2 can use more like 117-127, and a 3.54 can use 130-140. Porting that is right on the upper limit of a 3.0 is tame on a 3.2 and under ported on a 3.54. What that means is that if they all have the same flow, they will all make about the same hp, just at different rpm. The 3.0 will do it at 7700, the 3.2 at 7200 and the 3.54 at 6500. The bigger engines will make more torque, but not more hp unless they have more air. I mentioned the same thing about Nick's monster. He had a lot of work done on his heads to make the 360 number. If you put the same heads and cams on a 3.0 liter, it's also quite capable of 360 hp, but at around 9000 rpm instead 7500 or 8 (I don't recall) or where Nick's peaked. I'm sure that he's still a little under ideal flow (and has a little more than ideal duation cams to make up) or he'd be looking at more like 400hp at 7500. I'd think the stock duration should be plenty for a 7700 rpm engine. I think when the heads go back on, the hp peak will be at 7700, suggesting less duration is really in order, or a slightly higher redline. Ferrari got the duration pretty close, it's the lift they missed the boat on. If money were no object, I'd have a set of .400-.450 lift intake cams going on order right now, but it is an object, so it's .350" lift 328 cams for me.
I feel pretty confident that if the numbers work out as predicted, a 330-340 hp Mondial with a lot of torque, bulletproof reliability and DIY maintenance will be, at least for me, an almost perfect car. For me, it's all about balance. I'll be holding at 3.2 liters for a while yet.
That would be the perfect solution as I need an outwardly unchanged engine for the car here in Singapore, however, the one going back to England can have a supercharger bolted on. My difficulty is cash flow. It has not been (and is not) cheap to create and develop the Monzer and what is left to do before even the first one is finished is scary. I still don't know what the whole thing will have cost me - actually I probably don't want to know. That said, however, the new looks of the car demand more power. Mark's supercharger would be great if we could either work out some form of stage payments or Mark could sell it to me later. Of course more power requires better brakes, upgraded clutch etc adding further to the cost. The difficulties I face here on this small island are finding the necessary skills locally. For example I need to build my own vacuum forming machine as the only people here who do vacuum forming are Bell Helicopters and they are not interested in my project. Another example is that I will have to buy my own corner weight scales as I have not yet found any one here who has a professional installation for setting up the chassis. All of these things cost money. The car that goes to England will have to be sold after (hopefully) receiving suitable positive publicity in the motoring press. This is a financial necessity to allow me to develop subsequent cars.
