Clevo120Y 815 Posted October 1, 2013 Tony I would like to get my hands on one of those manifold but to be truthful I don't have 2 coins to rub together at the moment LOL, I have a few different cam profile cards here so I might start going through them and have a look, good luck with you head mate. Sly you read my mind, I was going to tighten up the lash a bit, I might start in the low teens cold and go from there. Share this post Link to post Share on other sites
matt_lamb_160 252 Posted October 1, 2013 I like that you have to work with a restriction, means you need to do it right. Your head achieves the manifold flow at less than 0.35" lift. In lift versus flow terms you don't really need more than 0.45"-0.5" lift. But then how do you get the duration you need and a fast ramp rate if you have such low lift? I would be aiming for 0.5"-0.55" lift with as flat a nose as possible (but this would require a helpful cam grinder). Running more lift will give the same flow but will require the engine to do more work (as Ando said). I would also be running wide-ish lobe separation (110 or so deg.) to help with the restrictive intake. The head's ports are better than they need to be, but because the cross-section has been maintained there will be no negative effects. The low lift mods are all that was really required, but this head is a great all rounder and will work with much better intakes as mentioned above. We need square cam lobes and some magic way of keeping the lifters on them, haha. 1 Clevo120Y reacted to this Share this post Link to post Share on other sites
Duckboy01 6 Posted October 1, 2013 what size exhaust valve will you be using, have you done any flow testing on the exhaust side? I use a 560" lift cam with 107 lobe sep which works well. Share this post Link to post Share on other sites
Crazy2287 1,886 Posted October 1, 2013 Posting in epic thread. Die grinding short turns without flow bench as an experiment on a car you don't care about like a boss. http://i346.photobucket.com/albums/p425/crazy2287/Ford%20Corsair%20project/DSCF1201.jpg Carry on gaiez. lovin' this thread. Share this post Link to post Share on other sites
Clevo120Y 815 Posted October 1, 2013 Matt the cam I'm using has 542th of lift so even tho the flow will top out quite early having a higher lift lobe means that it will be in the fat part of the lift flow for longer, plus during the first half of the induction stroke the depression applied to the port and intake will be higher than a test pressure of 28in's so will draw on the induction harder and will pull a lot more air, the second half of the induction is all piston driven and starting to slow down so the depression will be lower than 28in's, so the manifold restriction will have 1 benefit (you have to look for a silver lining) that the airspeed will stay quite high and maintain good mixture motion. This should give a good torque curve. Daniel I haven't decided on valve size yet, I have flow tested a stock port and valve in the exhaust, and comparing the figures against the port I worked on the flow ratio's would suggest going up a size BUT because of the manifold restriction I'm leaning towards sticking with the stock 1.5in valve, I will do a proper flow test with the intake manifold on recording at all lift points instead of the topend flow I have tested it at so far. The low lift ratios (overlap period) is at 70% which is ok, they drop away to 60% in the rest of the lift range, I'm still studying on the effects of these ratios at different lifts and which actually affect each other, the maximum flow percentage is a factor but what about the mid lift ratio? does it have an influence because the 2 valves aren't open at mid lift together?? these are the questions I'm asking myself at the moment. So undecided at this point let me get back to you. Crazy I'm glad you find this thread interesting mate, we both like to put the questions and theory out there, it's good fun to rummage through all the different opinions and come to a conclusion hey. Share this post Link to post Share on other sites
ando76 4,354 Posted October 2, 2013 Spot on. Low lift figures create the acceleration required to overcome the restriction in the manifold. More duration on the cam also helps, more time for air fuel to enter equals more power. Boys ran their race car up on the dyno yesterday with the new manifold fitted. 25hp gain and they were still pulling fuel out of it. They ran out of jets at 12.1 AFR so there is still plenty in it. Another happy customer. 2 Clevo120Y and Thom reacted to this Share this post Link to post Share on other sites
matt_lamb_160 252 Posted October 2, 2013 Exhaust to inlet ratios should never go below 60%, high ratios (above 80%) are not a concern so long as you are not giving up inlet flow to improve the exhaust. There is a heap of stuff in technical papers/books that came mostly out of MIT back in the day (Charles Taylor mostly) and have since been supported by people like Vizard and Bell. I would not be worried about low lift ratios of 85% (not that this will be an issue in your case) and would be trying to make sure I had at least 70% most of the time. I would consider the ideal 75% as an average value over the whole lift cycle which can be altered by the cam and/or the head. In your application you need to analyse the ratio with the inlet manifold on and you will need to make the assumption that, on the exhaust side, the head is the most restrictive item. Then make sure you don't get less than 70%. Chances are the stock exhaust valve size will be ok. Also the point you make about the higher lift lobe and fat part of the cam is exactly what I was trying to say and is why I recommended up to 0.55" lift. 1 Clevo120Y reacted to this Share this post Link to post Share on other sites
Duckboy01 6 Posted October 2, 2013 Spot on. Low lift figures create the acceleration required to overcome the restriction in the manifold. More duration on the cam also helps, more time for air fuel to enter equals more power. Boys ran their race car up on the dyno yesterday with the new manifold fitted. 25hp gain and they were still pulling fuel out of it. They ran out of jets at 12.1 AFR so there is still plenty in it. Another happy customer. What manifold are they using now and what were they using? Share this post Link to post Share on other sites
Clevo120Y 815 Posted October 2, 2013 Thanks Matt, your right I won't get a real look at the ratios until I flow test with the manifold on plus I realised that the exhaust figures I had aren't accurate because I took them before I calibrated the bench. So I will redo that test as well. Yeah I want the exhaust ratios up around 80% but knowing were it is important to have them is what I'm looking at. I also agree that the stock exhaust size will probably be the right size. Tony that's good to hear mate, I'm also interested in the results compared to what, were they running a modified manifold to start with? either way it proves the manifold is much more efficient. Share this post Link to post Share on other sites
ando76 4,354 Posted October 2, 2013 $1500 cut and shut manifold prior. New manifold after. 1 Clevo120Y reacted to this Share this post Link to post Share on other sites
Clevo120Y 815 Posted October 3, 2013 Brilliant results then Tony, you and Mark must be pretty pumped about that, how many of these manifolds are out there? Share this post Link to post Share on other sites
ando76 4,354 Posted October 3, 2013 Yeah mate real happy. They perform really well as cast but with a few minor touches on the high speed side of the port face they really take off. To date that is all we have done to them. I'm sure there is more in them but I'm reluctant to play too much. To answer your question about how many are out there - Not as many as I or Mark would like. lol. Most people are happy to pay someone $1500 for a cut and shut manifold that has not been tested but they seem to balk at considerably less than that for a manifold that has tried and proven results. I don't understand it myself. Guess its just human nature. Share this post Link to post Share on other sites
ando76 4,354 Posted October 3, 2013 Well the flow results are in from my new head done by Cam @ Engine Engineering in Brisbane. Cam and I have been friends for a long time and he did my first cylinder head 5 or so years ago. We collaborated heavily on this head, comparing ideas and thoughts and to say that I am happy with the initial flow results is an understatement. These results are from a different flow bench than I usually use, but I'm sure they will be pretty close. They are measured at the industry standard of 28 inches of water. Anyway as promised here they are; LIFT STD HEAD BERTHA 050 29.4 30 100 54 62.6 150 77.4 96.8 200 98.5 124.4 250 121.2 149.4 300 141.4 167.8 350 162.9 187 400 177.7 202.9 450 184.4 215.4 500 186.2 221.2 550 189.2 220.4 600 215.4 650 215.4 I love the way this head accelerates in the low lift and then just keep going thru to 550 and then only loses 5cfm in the next .100" of lift. All without enlarging the port size. Cam believes that there is a little more in it now that he has the results so he is going to try a few things and hopefully there will be further gains right across the board. I will not be posting pictures of the head or valve sizing, but those that know me, know I don't bullshit. Shows what can be achieved through stock port sizing. Enlarging the ports would improve the high lift figures in a four barrel or individual runner carb set up but that is not the design brief for this head. Can't wait to get it home and flow it with the new inlet manifold. Share this post Link to post Share on other sites
matt_lamb_160 252 Posted October 3, 2013 Wow, makes the old manfold expensive. Would like to see flow figures for the new manifold. Share this post Link to post Share on other sites
Clevo120Y 815 Posted October 3, 2013 test1 test2 test3 50 29.4 30.95 36.08 100 54 58.34 63.15 150 77.4 85.6 92.5 200 98.5 108.98 121.92 250 121.2 131.56 149.84 300 141.4 151.05 165.2 350 162.9 168.79 178.97 400 177.7 180.13 190.17 450 184.4 189.02 198.22 500 186.2 197.22 202.96 550 189.1 203 207.93 600 214.2 213.98 650 213.44 213.4 700 212.16 212.2 LIFT STD HEAD BERTHA 050 29.4 30 100 54 62.6 150 77.4 96.8 200 98.5 124.4 250 121.2 149.4 300 141.4 167.8 350 162.9 187 400 177.7 202.9 450 184.4 215.4 500 186.2 221.2 550 189.2 220.4 600 215.4 650 215.4 Share this post Link to post Share on other sites
Clevo120Y 815 Posted October 3, 2013 Sorry I just put the results together so I could compare, Your head leaves mine for dead after 300 thou of lift good stuff Tony, valve size might come into play at that stage, you must be stoked with those results. Share this post Link to post Share on other sites
Duckboy01 6 Posted October 3, 2013 Yeah mate real happy. They perform really well as cast but with a few minor touches on the high speed side of the port face they really take off. To date that is all we have done to them. I'm sure there is more in them but I'm reluctant to play too much. To answer your question about how many are out there - Not as many as I or Mark would like. lol. Most people are happy to pay someone $1500 for a cut and shut manifold that has not been tested but they seem to balk at considerably less than that for a manifold that has tried and proven results. I don't understand it myself. Guess its just human nature. What manifold is the new one? Share this post Link to post Share on other sites
Clevo120Y 815 Posted October 3, 2013 Secret Squirrel business Daniel LOL, I'm sure Tony will drop you a PM. Share this post Link to post Share on other sites
ando76 4,354 Posted October 3, 2013 Drop me a PM and I will explain duckboy. Yeah I am stoked. With the thought of more to come I am even more pleased. I know how well my old head performed in flat tappet form and with my old cut and shut manifold, so this head with a custom roller cam and the new manifold is going to go real close to attaining my goal. Matt - yeah it does. They love the new mani - they were going to ring me and ask me where there engine had gone after they fitted it and ran it. It makes the engine that much happier. Exactly the same as I experienced when I bolted mine on 'as cast' and had to go down 7 jets sizes to get afr's anywhere near close. If you have a good cut and shut manifold the total horsepower gain will not be that great but the torque curve is where you will see the greatest difference - oh and you will use less fuel and your oil will become less contaminated. not bad advantages I say. but I'm hardly impartial. The boys are and they used a separate dyno to me so the results and gains are the same. Good enough for me. 1 Clevo120Y reacted to this Share this post Link to post Share on other sites
Flatchat 4 Posted October 6, 2013 C2 head 1.85" inlet, 1.56" exhaust Lift Inlet Exhaust 100" 66.3 68.4 200" 131.5 105.8 300" 190.3 135.8 400" 233 158 500" 253 173 550" 254 178.6 Share this post Link to post Share on other sites
ando76 4,354 Posted October 6, 2013 Gee that's some impressive figures if they are at 28" of water. Would like to know a few more details like initial port sizing and chamber mods. That is a rocket ship up to .500 and then tapers so I'm thinking that the ports aren't that big. But I guess at the end of the day we aren't comparing apples with apples, unless we all send our heads to Clevo120 and have them flowed on his bench. What I like most about his thread is that he is detailing the effect each modification has on flow. I'd hate to see this thread descend into a pissing contest and I only posted my figures as Clevo asked. 1 Clevo120Y reacted to this Share this post Link to post Share on other sites
Flatchat 4 Posted October 6, 2013 Oh sorry my bad, how can I delete it Share this post Link to post Share on other sites
slydog 7,873 Posted October 7, 2013 Just involve yourself,offer and supply info like the basis of the thread.Any more info of what you use it for car type and so on...who did the work and such? 2 ando76 and Clevo120Y reacted to this Share this post Link to post Share on other sites
gerg 10,871 Posted October 7, 2013 With the cross-flow being a very similar design to the Clevo in the ports (except entry chape), could a 2V benefit from a blend and short-turn tidy up? Would it be worthwhile? Anyone got flow figures for both stock and tidied-up 2V heads? I've wondered about biasing the porting to one side of the port to promote swirl - now i have to wonder no more. This is a great thread... Keep it up! 2 slydog and Clevo120Y reacted to this Share this post Link to post Share on other sites
ando76 4,354 Posted October 7, 2013 Oh sorry my bad, how can I delete it as Sly said, don't delete it just give us some more info etc. It is human nature to question someone who enters a forum with a post like that, it happened to Wazzy once but we have learnt that he can back up his claims with solid numbers. So I guess what we are trying to say is give us some info as for me, these forums and threads are about learning from one another so we can improve the breed. 1 Clevo120Y reacted to this Share this post Link to post Share on other sites
