Butcha 111 Posted July 9, 2014 Woo ease up there a bit ando these fellas dont run an 8" race tyre lol. Be cautious about taking too much gear out of it as it will increase wheelspin specially after the watercarts been out. You will find to a point he will still hit the same revs. Next step down in diff gear is 3.08 which will increase wheelspeed 6kmh at the same revs. Its not much but it makes a big difference in how it pulls. I agree he is peaking a little too soon but he is almost there. Go too far the other way and he will suffer coming out of the corner. Assuming a 225 tyre wheel speed is with 3.23 is appox 114kmh a 3.08 will give you 120kmh and a 2.92 is 126kmh and 133kmh with 5.5. Watch the revs drop on corner exit each time you go down in gear those revs will drop exponentially. Especially if it falls below pk torque point. My 2 bobs anyways. Sorry clevo im bored waitin for me plane out 1 Clevo120Y reacted to this Share this post Link to post Share on other sites
Campo 869 Posted July 9, 2014 Max tyre size in a streety is 215/65 1 Clevo120Y reacted to this Share this post Link to post Share on other sites
ando76 4,354 Posted July 9, 2014 Yeah but tyre size makes no difference to the fact that its pulling way too many revs - too early. The shift light tells me that regardless of the race tyre or radial. Pulling revs out of it and torqueing it up will DECREASE wheel spin as it brings the engine back into the torque range not in the RPM high, HP zone. This is where soo many people go wrong in speedway in crossflow applications. They make quicker lap times when they are torqued up. Trust me. Butch - remember when Kev Wyatt got involved with Max Bennetts and A. he stopped blowing engines and B. he won 6 in a row before having a year off last year - WHY because Kev pulled teeth off and it went faster and faster. It is not about the wheel speed difference you have highlighted - its about the way the car puts the power down and the ability to get back on the gas earlier and have the engine torque out of the corner and make passes. I'll have a $100 that a gearing change to 5.8 will a) make the car easier to drive and improve lap times. 1 Outback Jack reacted to this Share this post Link to post Share on other sites
Butcha 111 Posted July 9, 2014 Ando I agree with you to to an extent but going to a 6.4 down to 5.8 a huge step. My $100 says its too far and he wont have the hp to turn it I only mention wheel speed as a point to illustrate the gearing difference. Share this post Link to post Share on other sites
Clevo120Y 815 Posted July 9, 2014 Yes Tony too rich LOL I had to reread my post, I must of been thinking about leaning it out or something. We are going to try the 3.08 to start with because I don't want to loose the punch out of the corner, if she still pulls hard we might go to the 2.92 and tune it with tyre size, chuck a 14in rim on for the short tracks etc etc. Share this post Link to post Share on other sites
Clevo120Y 815 Posted July 9, 2014 The engine shows plenty of torque as it pulls from the rolling start in second quite well. Share this post Link to post Share on other sites
Campo 869 Posted July 9, 2014 What length is that track? Share this post Link to post Share on other sites
Campo 869 Posted July 9, 2014 Ah yeah. I'd start with a 3.08 in my el street stock on a track that size, not sure that I'd be going such a drastic change as 2.77 or 2.92. 1 Clevo120Y reacted to this Share this post Link to post Share on other sites
Clevo120Y 815 Posted July 9, 2014 Here is another short vid of the next round at Mt Barker, the track is rough as guts LOL, I had trimmed a bit of fuel out of it for this race and took more out for the next race to get it in the 12's. Mt Barker is a much shorter track than Albany. 1 Outback Jack reacted to this Share this post Link to post Share on other sites
ando76 4,354 Posted July 9, 2014 Ah ha. Now look at the difference in the shift light and the way the car pulls and drives out of the corners. That gearing is near on perfect for that track. The shift light comes on right on turn in and the car is torqued up in the corners and pulls out like a freight train and apart from getting turned around it looked easier to steer. Look how fast it deals with the cars off the line and then how quickly is pulls in that injected black falcon and then eats it. Even when he has the big understeer 'oops' the car is in the fat part of torque and it just pulls away. The engine would have to be mighty good to be making power past 5600 so why take it there. Going from 3.23 to 3.08 on the 440m track is a futile exercise IMHO as it is not enough of a change to notice any difference. The way that car pulls off the line and out of the corners tells me that it will pull 5.8 final drive without an issue on the 440m track If the 440m track usually goes 'Dry/Slick' for the feature I would have 5.8 in there in a heart beat. In my experience in speedway it is often better to make a big change in order to have a reference point. I'm also a firm believer of listening to what the car is telling you - not what everyone else is doing - do what the car is telling you and that car at the 440m track is telling me a lot particularly through the shift light. EDIT : but you guys do want you think is best. I'm on my high horse again so I will calm down and hop off - Sorry . 1 Clevo120Y reacted to this Share this post Link to post Share on other sites
Outback Jack 6,352 Posted July 9, 2014 I gotta agree with Ando, Change it for the longer track, 2.92 to start. I'd put 100 on it, but thats half me pension after the new Emporer Ming changes. haha Fark you Barnett, West Australia hates you too. I havent raced speedway. (Well once, mechanics race, I flew off the side of the track after hitting a patch of rock and got the horses arse trophy....... but I was 16..... lol) . I pit crewed mostly, and drank all their beer. hehe I just find the topic interesting. There is no point in taking an engine past its max torque revs... you won't go any faster, just makes the motor work too hard. I have taken much faster cars than mine off the mark, just by having the correct gearing. Jack. I 1 Clevo120Y reacted to this Share this post Link to post Share on other sites
Clevo120Y 815 Posted September 30, 2014 Well the engine got dropped off and now time to make some changes but first a full inspection is in order to make sure it survived the flogging it copped hahaha. So far the topend is all mickey mouse, I will pull down the bottom end tomorrow and check bearings ect ect. Had to recheck deck height as I lost my notepad with all the details from last time Share this post Link to post Share on other sites
Clevo120Y 815 Posted September 30, 2014 249.525 Cubic Inches @ 5500 RPM with 98.33 % Volumetric Efficiency PerCent Required Intake Flow CFM @28 in. = 165.0 to 174.7 at .548 inch Valve LiftRequired Exhaust Flow CFM @28 in. = 128.8 to 139.6 at .518 inch Valve Lift 600 RPM/Sec Dyno Test Lowest Low Average BestPeak HorsePower 251.3 256.6 259.9 263.2Peak Torque Lbs-Ft 264.7 271.7 274.6 278.6 HorsePower per CID 1.007 1.028 1.042 1.055Torque per Cubic Inch 1.061 1.089 1.103 1.117BMEP in psi 160.0 164.2 166.3 168.4Carb CFM at 1.5 in Hg. 390 434 456 478 Recommended Intake Valve Lift to prevent Choke = .548 Lift @ 5500 RPMRecommended Exhaust Valve Lift to prevent Choke = .518 Lift @ 5500 RPM Recommended Minimum Normal Maximum Time-Area-Duration Lifts Intake Valve Lift = 0.4868 0.5483 0.6032 0.6251 0.6589 0.6927 Exhaust Valve Lift = 0.4762 0.5176 0.5694 0.5880 0.6248 0.6616IntOpen= 9.50 IntClose= 41.50 ExhOpen= 45.50 ExhClose= 5.50Intake Duration @ .050 = 231.00 Exhaust Duration @ .050 = 231.00Intake CenterLine = 106.00 Exhaust CenterLine = 110.00Compression Duration= 138.50 Power Duration = 134.50OverLap Duration = 15.00 Lobe Separation Angle (LSA)= 108.00Camshaft Advanced = 2.00 degrees Cylinder Ignition Interval= 120 deg. -- Operating RPM Ranges of various Components --Best estimate RPM operating range from all Components = 3464 to 5464Intake Flow CFM @28inches RPM Range from Flow CFM only = 3426 to 5426Intake and Exhaust Systems operating RPM Range = 3372 to 5372Intake and Exhaust Time-Area operating RPM Range = 2992 to 4992Camshaft's Intake and Exhaust Lobes operating RPM range = 3565 to 5565Intake Valve Curtain Time-Area at 0.550 Lift RPM Range = 3517 to 5517Exhaust Valve Curtain Time-Area at 0.550 Lift RPM Range = 3844 to 5844 Intake Valve Close RPM = 5594 Exhaust Valve Open RPM = 5478Intake System RPM = 5326 Exhaust System RPM = 5418Intake Time-Area RPM = 4839 Exhaust Time-Area RPM = 5145Intake Mach Z-Factor = 0.483911 Exhaust Mach Z-Factor = 0.600718Intake Z-Factor Lift = 0.554482 Exhaust Z-Factor Lift = 0.500598 Curtain Area -to- Valve Area Convergence Intake Valve Lift inch= .450Curtain Area -to- Valve Area Convergence Exhaust Valve Lift inch= .363 Target EGT= 1397.0 degrees F at end of 4 second 600 RPM/Sec Dyno accel. testOctane (R+M)/2 Method = 91.9 to 94.5 Octane required rangeAir Standard Efficiency = 60.51011 % for 9.860:1 Compression Ratio ------- Piston Motion Data -------Average Piston Speed (FPM)= 3584.17 in Feet Per MinuteMaximum Piston Speed (FPM)= 5899.011 occurs at 74.04991 Degrees ATDCPiston Depth at 74.050 degree ATDC= 1.7059 inches Cylinder Volume= 297.3 CCMaximum TDC Rod Tension GForce= 2203.0711 G'sMaximum BDC Rod Compression GForce= 1156.4116 G's ----- Engine Design Specifications ----- ( English Units ) ( per each Valve Sq.Inch area )Engine Size CID = 249.525 Intake Valve Net Area = 2.472CID per Cylinder = 41.587 Intake Valve Dia. Area = 2.545Rod/Stroke Ratio = 1.605 Intake Valve Stem Area = 0.073Bore/Stroke Ratio = 0.941 Exhaust Valve Net Area = 1.579Int Valve/Bore Ratio = 0.489 Exhaust Valve Dia. Area = 1.651Exh Valve/Bore Ratio = 0.394 Exhaust Valve Stem Area = 0.073Exh/Int Valve Ratio = 0.806 Exh/Int Valve Area Ratio = 0.649Intake Valve L/D Ratio= .306 Exhaust Valve L/D Ratio= .379CFM/Sq.Inch = 64.8 to 68.7 CFM/Sq.Inch =76.6 to 80.5 Intake Valve Margin CC's Exhaust Valve Margin CC's1.00 CC = 0.0240 1.00 CC = 0.03700.50 CC = 0.0120 0.50 CC = 0.01850.25 CC = 0.0060 0.25 CC = 0.00920.10 CC = 0.0024 0.10 CC = 0.0037 - Induction System Tuned Lengths - ( Cylinder Head Port + Manifold Runner )1st Harmonic= 36.551 (usually this Length is never used)2nd Harmonic= 20.745 (some Sprint Engines and Factory OEM's w/Injectors)3rd Harmonic= 14.483 (ProStock or Comp SheetMetal Intake • best overall HP )4th Harmonic= 11.399 (Single-plane Intakes , less Peak Torque • good HP )5th Harmonic= 9.249 (Torque is reduced, even though Tuned Length)6th Harmonic= 7.781 (Torque is reduced, even though Tuned Length)7th Harmonic= 6.716 (Torque is greatly reduced, even though Tuned Length)8th Harmonic= 5.907 (Torque is greatly reduced, even though Tuned Length) Note> 2nd and 3rd Harmonics typically create the most Peak Torque 4th Harmonic is used to package Induction System underneath Hood Plenum Runner Minimum Recommended Entry Area = 1.760 to 1.980 Sq.InchPlenum Runner Average Recommended Entry Area = 2.023 Sq.InchPlenum Runner Maximum Recommended Entry Area = 2.067 to 2.446 Sq.Inch Minimum Plenum Volume CC = 524.8 ( typically for Single-Plane Intakes )Minimum Plenum Volume CID= 32.0 ( typically for Single-Plane Intakes )Maximum Plenum Volume CC = 4089.0 ( typically for Tunnel Ram Intakes )Maximum Plenum Volume CID= 249.5 ( typically for Tunnel Ram Intakes ) --- Cross-Sectional Areas at various Intake Port Velocities (@ 28 in.) ---127 FPS at Intake Valve Curtain Area= 3.110 sq.in. at .550 Lift156 FPS at Intake Valve OD Area and at Convergence Lift = .450192 FPS 90% PerCent Rule Seat-Throat Velocity CSA= 2.061 sq.in. --- 5500 RPM Intake Cross-sectional areas in Square Inches ---350 FPS CSA= 1.130 Port has Sonic-Choke with HP Loss ( too fast FPS )330 FPS CSA= 1.200 Port may have Sonic-Choke with HP Loss ( too fast FPS )311 FPS CSA= 1.273 Highest useable Port velocity ( possible HP loss )300 FPS CSA= 1.320 Smallest Port CSA ( Hi Velocity FPS • good TQ and HP )285 FPS CSA= 1.389 Smallest Port CSA ( very good TQ and HP combination )260 FPS CSA= 1.523 Recommended average Intake Port CSA (very good TQ and HP)250 FPS CSA= 1.584 Largest recommended average Intake Port CSA ( good HP )240 FPS CSA= 1.650 Largest recommended average Intake Port CSA (less Peak TQ)235 FPS CSA= 1.685 Largest recommended Intake Port Gasket Entry area CSA225 FPS CSA= 1.760 Largest Intake Port Gasket Entry CSA ( Slow FPS )215 FPS CSA= 1.842 Possible Torque Loss with Reversion ( Slow FPS )210 FPS CSA= 1.886 Torque Loss + Reversion possibility ( too slow FPS )200 FPS CSA= 1.980 Torque Loss + Reversion possibility ( too slow FPS ) Note : these are calculated average Port cross-sectional areas and FPS --- Cross-Sectional Areas at various Exhaust Port Velocities (@ 28 in.) ---123 FPS at Exhaust Valve Curtain Area= 2.505 sq.in. at .550 Lift187 FPS at Exhaust Valve OD Area and at Convergence Lift = .363231 FPS 90% PerCent Rule Seat-Throat Velocity CSA= 1.338 sq.in. at 5500 RPM --- 5500 RPM Exhaust Cross-sectional areas in Square Inches ---435 FPS CSA= 0.711 Sonic Choke at Throat Area (too fast FPS velocity)380 FPS CSA= 0.814 Sonic Choke at Throat Area (possibly too fast FPS)350 FPS CSA= 0.883 Exhaust Port has Sonic-Choke with HP Loss (too fast)330 FPS CSA= 0.937 Exhaust Port has Sonic-Choke with HP Loss (too fast)311 FPS CSA= 0.994 smallest Exhaust Port ( very high velocity FPS )300 FPS CSA= 1.031 smallest recommended Exhaust Port (Hi velocity)285 FPS CSA= 1.085 smallest recommended Exhaust Port (Hi velocity)265 FPS CSA= 1.167 Recommended average Exhaust Port CSA250 FPS CSA= 1.237 Recommended average Exhaust Port gasket area240 FPS CSA= 1.288 Recommended largest Exhaust Port gasket area225 FPS CSA= 1.374 Largest Exhaust Port Exit gasket area (Slow FPS)210 FPS CSA= 1.473 Largest Exhaust Port Exit gasket area (Slow FPS)190 FPS CSA= 1.628 Torque Loss + Reversion + Scavenging loss (too slow FPS)180 FPS CSA= 1.718 Torque Loss + Reversion + Scavenging loss (too slow FPS) Note : these are calculated average Port cross-sectional areas and FPS Share this post Link to post Share on other sites
Clevo120Y 815 Posted September 30, 2014 A bit of light reading for ya's, this is the engines specs all matched up, this is how I put the details together, once you have the head flow figures with induction on etc etc, then you can start looking into cam profiles that suit intended flow rates with comp and the cross sectional areas that the head has. This is why the combination using mainly stock unbalanced parts can perform well using efficient methods for it's intended rev range which for this engine sits between 3500 and 5500, now to build a sump and make a couple of little changes and go faster this season. Share this post Link to post Share on other sites
Clevo120Y 815 Posted September 30, 2014 The only thing I can't get is the recommended carb cfm, so this will drop overall power, this combination with 4brl manifold and 465 would go really well with a bit of stall. 1 gerg reacted to this Share this post Link to post Share on other sites
slydog 7,873 Posted September 30, 2014 Dude you should be wearing a white coat 1 wagoon reacted to this Share this post Link to post Share on other sites
ando76 4,354 Posted September 30, 2014 Amazing the data you can get from those engine analyser program's. Good work again Sean. That deck height is pretty yucky and would be hurting squish. Be good to see it drop a bit and perhaps open the chamber a bit to drop the comp. I'll send you my flow figures for THOR and you can punch that into your analyser in your spare time. Lol. Share this post Link to post Share on other sites
Clevo120Y 815 Posted October 1, 2014 Yeah send it through Tony, I can't touch the head so chamber work is out, I can't zero deck it either, I can take a little bit off but not much, 39thou is not perfect but have to play in the rules . Cheers Rob yeah the program's make it easier but you still have to know how to interperate the info and balance the figures to something that will work in the real world. Share this post Link to post Share on other sites
Clevo120Y 815 Posted October 1, 2014 Hey Tony I have to have flow figures with the manifold and carb bolted on mate, then the average of all 6 cylinders, this is what gives me the VE value. Share this post Link to post Share on other sites
ando76 4,354 Posted October 1, 2014 Yep have all those figures as that is how I tested THOR and the carbies I was playing with. Oh and I can tell you the restriction has and always will be the manifold in this bloody restricted class racing but at least I have a manifold that flows even in every bloody cylinder now. Took awhile but we got there 1 Clevo120Y reacted to this Share this post Link to post Share on other sites
Clevo120Y 815 Posted October 7, 2014 So a bit of an update, the bearings were fine but going to put new shells in anyway, the cam and everything is mickymouse. The valve springs are stuffed, 85lbs on the seat they had reduced to, they are crow single with damper springs, I set them up with 110lbs and that's how soft they went in half a season of racing. So I am taking Tony's advice and setting the head up with the isky 235d springs to sort this problem out for good. I also started making a sump for this engine, it has to look standard from the outside so all the work is inside, I'm running 2 gates and a bit of a tray and baffles to control the oil. hopefully finish it up tommoz. started by making so templates Started cutting it all out and test fitted to a bare block with a pump and pickup in it. weld some hinges on and clean it up abit, here is also pics of what it will look like when it's all welded together, then I just have to put the trap doors on the hinges and test it out. 4 XTREME KARTS XF, Outback Jack, slydog and 1 other reacted to this Share this post Link to post Share on other sites
ando76 4,354 Posted October 7, 2014 swap the front flap over to the right hand side or directly in the middle if you run your races in both directions - that way the returning oil will go straight under the pick up. I'd also be gently peening down the area directly under the pickup so that there is always a well of oil under the pickup. You should be able to do it with a hammer and dolly and still retain a stock looking pan. Either that or cut the bottom off another sump and extend the bottom of your's down. some careful welding and grinding and a bit of filler and no one will ever know. More capacity is always a good thing. I'd be doing the same at the very back of the sump as the big ends goes very close to hitting and it is a shocking area for windage. That's why I extend that area down on mine but I understand you are not allowed to do that. 2 Clevo120Y and Outback Jack reacted to this Share this post Link to post Share on other sites
Clevo120Y 815 Posted October 7, 2014 Thanks Tony, and thanks for the sms's. Tony has pointed out some flaws in my pan which I now agree with, the louvers are the wrong way to work properly so I will have to remake that section also I will move the front gate to the right as Tony has said so I will remake that piece as well, half a day wasted but hey I learnt something today. Cheers Share this post Link to post Share on other sites
Clevo120Y 815 Posted October 7, 2014 So my above pics are a how not to lesson lol. Sitting in the shed tonight I have come up with another plan, this time I will use ally sheet and make the wind age tray cover the pickup area more, move the gate over etc etc. see how I go tomorrow. 1 Outback Jack reacted to this Share this post Link to post Share on other sites
