slydog 7,873 Posted October 15, 2013 Hmmmmmmm wonder if someone had a spare 4 barrel manifold they could send your way to do tests on and modify. 1 Clevo120Y reacted to this Share this post Link to post Share on other sites
Flatchat 4 Posted October 15, 2013 Don't go too crazy on the plenum as a 2 barrel metho carb 250 big plenum manifold will go backwards on hp... 1 Clevo120Y reacted to this Share this post Link to post Share on other sites
Clevo120Y 815 Posted October 15, 2013 Hmmmmmmm wonder if someone had a spare 4 barrel manifold they could send your way to do tests on and modify. Don't tease me mate LOL, IF someone does have a spare mani it will be well looked after Share this post Link to post Share on other sites
Clevo120Y 815 Posted October 15, 2013 Don't go too crazy on the plenum as a 2 barrel metho carb 250 big plenum manifold will go backwards on hp... 100% agree, 490cc of plenum I'm after and she is a proddy engine so 98 fuel, the part of the main body in the pic that is rusty colour will be plated up and not used so the volume will be under control. Thanks for the heads up anyway all input is welcome. Share this post Link to post Share on other sites
Flatchat 4 Posted October 15, 2013 Ure all over it, engine dyno testing showed and I'm not knocking any1 but the best 2barrel petrol carbed manifold over an ultraflow 2barrel manifold using a 500 meth Holley because of the big plenum over an ultraflow in stock form lost 50hp, the airspeed+meth dropped and lost its mix in a big plenum vs the ultraflows improved copy of a stock manifold.... Share this post Link to post Share on other sites
ando76 4,354 Posted October 15, 2013 I'm not sure I understand that last post Flatchat. My understanding is the Ultraflow manifold was made by Ian 'Moo' MOODY, very smart man who has made some awesome stuff over the years. The design was good at the time but I think there are better 2 barrel manifolds on the market at the moment that give more even cylinder fill. I think that is what Clevo 120y is trying to achieve with his cut and shut manifold. I have been exactly where he is at the moment - about four years ago. You need to enlarge that part of the manifold to allow for better airflow entry into cylinders 2,3,4,&5. Yes too big will kill it but it is more about shaping the chamber to make the most of the high speed air. Remember that the outside venturi is not exposed to the main plenum area as much as the inside venturi. Share this post Link to post Share on other sites
Flatchat 4 Posted October 15, 2013 Ando testing proved with the extra volume of meth added to a big plenum lost its airspeed and reduced the correct air/fuel mix needed for a clean burn, whilst it was on pump fuel with the lower fuel volume it tendered to keep a good mix of air/fuel ratio without separating, even flow runners works fantastic with a sided raft webber setup and thats what they were designed for but trying to emulate that with a 2barrel meth carb setup creates issues e.g. Slower Pockets of dead air, Clevo knows what he's doin as do u, just don't go crazy like the rest of the chev lovers do.... Share this post Link to post Share on other sites
AussieSpeed 9 Posted October 15, 2013 its funny looking at stuff like this, now some of you will appreciate the time that goes into development, i am currently working on a BA 4 barrel, 3 x DCOE manifolds for crossflow, 4.0l and BA, blower manifolds for, xflow, 4.0 and BA... plus a bunch of other stuff...i remember back 30 odd years ago when i started playing with this stuff how much shit people talk and how little they really know...Remember flow figures are not the be all and end all, the other thing with your development you will notice its difficult to make one manifold that suits all engine combos and work in all applications, thats why there are 3 different Aussiespeed 2 barrel manifolds for crossflows, good to see someone else is having a crack Share this post Link to post Share on other sites
ando76 4,354 Posted October 15, 2013 you are sooo right Mark. Clevo's work mirrors your work on the 'new' manifold. He is trying to achieve exactly what we achieved with the new manifold. Power to him, and to you for your continued work in making these engines sing. Share this post Link to post Share on other sites
ando76 4,354 Posted October 15, 2013 Ando testing proved with the extra volume of meth added to a big plenum lost its airspeed and reduced the correct air/fuel mix needed for a clean burn, whilst it was on pump fuel with the lower fuel volume it tendered to keep a good mix of air/fuel ratio without separating, even flow runners works fantastic with a sided raft webber setup and thats what they were designed for but trying to emulate that with a 2barrel meth carb setup creates issues e.g. Slower Pockets of dead air, Clevo knows what he's doin as do u, just don't go crazy like the rest of the chev lovers do.... It may not have worked in that application - what was the size of the initial part of the head runner? What flow figures did the head achieve? Did you try it on another combination. It all comes down to the combination. What works in one application can be destroyed in another with incorrect parts. To say that the ultraflow does not work in all meth applications is a long bow to draw - unless you can back it up with separate testing. That is why I have talked about the results of the new manifold on my engine and the results on another combination. It has worked on both and in fact everyone that has bolted it on has made a gain. That is how I feel confident in talking about the results it has achieved. Share this post Link to post Share on other sites
Flatchat 4 Posted October 15, 2013 Mark u are the leader in the development of the top performing engines in this country and in the areas u touch overseas, what u have developed and put a huge amount of work into with what you have available in today's market now covers all boundaries of 250 performance, u said it, as do with many others that found out the hard way time and time again proves flow benches only show numbers and figures and sometimes end up with disappointing figures, why work a manifold when there's already 1 that's made for the job, I love tinkering and these threads are furthering every1s interests in these motors, keep pushing the boundarys I say.... Share this post Link to post Share on other sites
Clevo120Y 815 Posted October 15, 2013 Thanks guys, I'm glad this thread has sparked up the conversation about different combinations, that is exactly my thinking with this engine, my plenum volume is my target for this engine but may need tweaking for a different combination. I fully understand the effort and time that goes into making something like this Mark, what you have achieved is brilliant. It sounds like I'm on the right path to get good results by Tony's comments which I'm very happy about. Share this post Link to post Share on other sites
Flatchat 4 Posted October 15, 2013 Ando the head flow figures I posted previously compared to the combo on this thread were improved again overall, testing wasn't a half arse job and the ultraflow at the time fixed the low temp rich fuel burn in no.1 and 6 cyl, no testing has been done like ures with the new manifold and none is needed as ure result prove Share this post Link to post Share on other sites
Clevo120Y 815 Posted October 15, 2013 People are correct that a flow bench results aren't the be all BUT doing this sort of work couldn't be done without one, you are just guessing if your not using one. The amount of things I've discovered in the short amount of time that I have had my flow bench for is crazy, the most important part of a flow bench in my opinion is the velocity probes, to be able to see the speed of the air and were it wants to be and to be able to determine at which point the speed is so high it becomes a sonic choke plus feel the turbulence while holding the probe is invaluable. Also being able to hear the air tells you a lot, you would be amazed at what shapes do what to airflow and the roar it makes when the air shears off a turn and crashes. Even the way you can manipulate the flow with lumps of plasticine and the strange shapes that give good gains. If you get the velocities correct and stable the CFM numbers follow, I believe I showed this in the head flow thread, the airflow was even and stable all the way past 600 thou of lift because in my opinion the port shape is good, even tho the cfm numbers aren't earth shattering I am confident that is due more to the stock valve, worn seat and small cross sectional area than anything else, Once these things are optimised I think good gains will be made across the lift range. Most of all this is just great fun, sitting in my shed playing around with car parts is my heaven, even if the results go backwards I learn something from it. 3 slydog, ando76 and Thom reacted to this Share this post Link to post Share on other sites
ando76 4,354 Posted October 15, 2013 All good Flatchat. Clevo you are on it with your flow bench and the way that you use it. A wise man once said "I've never seen a flow bench win a race" which is true to a point. They are like dyno in my eyes. Tuning tools to see gains or loses. Keep up the good work. 1 Clevo120Y reacted to this Share this post Link to post Share on other sites
Clevo120Y 815 Posted October 16, 2013 I ported out the sections of runners today and tested them on a head to check the velocities and flow, you can see that I have filled the section that will be filled with plasticine to simulate what the end shape will be, it performed well and runners 1,2 and 5,6 flow the same so I'm happy with that consistency, also gained 10cfm over the first manifold so a win there also, next I have to fill the playdo areas with alloy then move onto the centre section. 1 ando76 reacted to this Share this post Link to post Share on other sites
slydog 7,873 Posted October 16, 2013 Awesome work bro... 1 Clevo120Y reacted to this Share this post Link to post Share on other sites
ando76 4,354 Posted October 16, 2013 shape looks good. Be interesting to see if they flow any differently when the manifold is together as a whole. This manifold will perform very well I do believe and 'balance' the engine which makes for a much happier engine. Best I get out to the shed with the die grinder to see where I can improve the new manifold or you will be overtaking it. Great update. 1 Clevo120Y reacted to this Share this post Link to post Share on other sites
deankxf 20,288 Posted October 17, 2013 i'm surprised by the results of porting the manifold. i read an article years ago about extrude honing (pumping an abrasive goo through ports of things to improve flow etc. cutting one open is something i hadnt seen before) had me wondering if you could sand cast the external stock manifold then do the perfect port/plenum shape inside that casting.. then recast it in alloy having all the stock part numbers etc showing would be a cheeky way to go. what crosses the line in "using the stock manifold?" cutting and welding, changing the internals.. complete internal re cast of the runners? etc 1 Clevo120Y reacted to this Share this post Link to post Share on other sites
slydog 7,873 Posted October 17, 2013 Seen it done plenty of times on speedway engines but most of the time it was done with a measuring tool IE flow bench.But I hope this thread is showing just little material needs to be removed more along the lines of reworking whats there to get needed flow.Only when you move up to big comp big induction big cam's do you need a large runner and or head ports. Again good work Clevo and props for posting it all up. 2 Thom and Clevo120Y reacted to this Share this post Link to post Share on other sites
Clevo120Y 815 Posted October 17, 2013 had me wondering if you could sand cast the external stock manifold then do the perfect port/plenum shape inside that casting.. then recast it in alloy having all the stock part numbers etc showing would be a cheeky way to go. This is exactly what Tony and Mark have done with there new manifold, there manifold is worth every cent as it hasn't been cut and shut so won't have any chance of being pinged for it, the rules state that it has to look stock from the outside so if they can see joins and welds it will be deemed illegal so I have to do the best I can to make the joins disappear. Others have told me they cut the manifold completely in half horizontally, port it then weld it back together, I have heard talk of it but have never seen one done that way, I would think the amount of welding needed to join the complete circumference of the manifold would be hard to hide and hard to just do in general. There is a lot of work going into this manifold and no garentee that it will pass inspection, my advice would be to speak to Tony if a manifold like this is required because I couldn't make one for someone charging my time for less than Tony's manifold, I might be talking myself out of work here but it's the truth, I'm just having a go for personal satisfaction to see if I can get close to the performance of the aftermarket manifold. 1 deankxf reacted to this Share this post Link to post Share on other sites
Clevo120Y 815 Posted October 17, 2013 Seen it done plenty of times on speedway engines but most of the time it was done with a measuring tool IE flow bench.But I hope this thread is showing just little material needs to be removed more along the lines of reworking whats there to get needed flow.Only when you move up to big comp big induction big cam's do you need a large runner and or head ports. Again good work Clevo and props for posting it all up. Sly is spot on here, it is all about the shape not the size, the size needs to be correct for the airspeed needed but it is smaller than what people would think. The size also changes to control speed at certain points of the port, when air goes around a corner the short side of the turn needs to be made wider and flatter to slow the air just enough for it to hang on going around the corner then back to a smaller shape to pick the airspeed back up and so on. Different combinations need a different head port also in size and shape, for example Sly's race motor I would make the head port as straight as I could, completely different to the port I did for this engine. Sly's engine will be used in a smaller rev range at VERY high revs so port speed will be up just from the revs alone, giving it as straight a port as possible is the way to go and the port can be bigger because of the higher rev range, this would hurt low rev performance but the ute is setup with a high stall and such so that part of the rev range is bypassed, this is part of the whole combination for everything to suit. 3 ando76, slydog and Thom reacted to this Share this post Link to post Share on other sites
Clevo120Y 815 Posted October 17, 2013 shape looks good. Be interesting to see if they flow any differently when the manifold is together as a whole. This manifold will perform very well I do believe and 'balance' the engine which makes for a much happier engine. Best I get out to the shed with the die grinder to see where I can improve the new manifold or you will be overtaking it. Great update. I think I will loose a little bit of flow with it all together, as long as I still have my original 165cfm like the other manifold I can't complain because I will have the plenum I want, gut feeling is 170cfm when all together which will be a win win. I hope it performs on the track Tony, I think it will I don't see my manifold overtaking yours just yet it is only my second go at one and I have made improvements over the first already in the end runners, I am concerned that runners 3 & 4 will outflow the others having direct access to the bigger plenum but we will see. PS I will return a PM to you soon Tony, Cheers Share this post Link to post Share on other sites
ando76 4,354 Posted October 17, 2013 all good man. I'm just looking at making a few alterations to the new manifold and have brought another one from Mark in case I go backwards. LOL. No one has really played with the new manifold as they are just so good out of the box. I compared the new one to my old TRUSCOTT/ WYATT one and just got a few idea I want to try to see if I can make a gain. Your work is driving me to the die grinder. Been a bit busy with the skid ute and a few other bits and bobs but I will get there and then I might post it down so you can run it up on your bench - if your keen. 1 Clevo120Y reacted to this Share this post Link to post Share on other sites
Clevo120Y 815 Posted October 17, 2013 Get into it mate LOL for sure I would be interested in you sending a manifold down for testing, I would really like to have a look at one. It gets addictive when you start making gains, I dream about the shit at the moment hahahaha sad I know Burnout ute??? I have to start venturing out of the 6 cylinder section and checking out the build threads Share this post Link to post Share on other sites
