plytme 2 Posted March 20, 2014 Another cool thread from Clevo120y. I really enjoyed your thread on the cylinder head, as I stated it was way over my head lol, but I am starting to learn a bit which is cool thanks. This thread however I understand, pretty cool ideas you've come up with, well done. Reading threads like yours and Sly's ute build has really inspired me to get cracking on with my Corty hopefully body work should be finished shortly then time for some paint and engine. Good to hear you are making some money out of this congrats. Share this post Link to post Share on other sites
gerg 10,871 Posted March 20, 2014 Top work mate, always interested in your latest mad scientist creations. Have you thought of taking a mould of the prototype in body filler and then making a few from epoxy/glass? Share this post Link to post Share on other sites
unfamilia 1,938 Posted March 20, 2014 Can you mould that shape with fibreglass over the top. Would be hollow under neath. Or even that expanding foam crap. Share this post Link to post Share on other sites
Clevo120Y 815 Posted March 20, 2014 Cheers guys for the positive feedback I really appreciate it. The flow bench is the best tool I have, I'm starting to really see the benefits of using it, not just for cylinder heads but anything that has any sort of airflow related function. I can even use just the velocity probe to map aerodynamics over a surface and shit LOL, develop efficient shapes for cold air intakes etc etc. The aircleaner holes weren't just a random guess on there placement, I measured the pressure difference in a stock housing and I could tell at what point would benefit the most to airflow, The housing is so efficient now I can block off the original snorkel that sucks air from directly above the exhaust manifold and with this blocked off I loose none of the extra flow I gained. Fibreglass is a good idea, I did a fibreglass course when I did my auto accessories fitter ticket LOL time to bust out the matting. Sly Bro I would be happy to re do the manifold mate, angle milling is the go but I would like to see how it goes before I hack into it again HAHAHA, already planning changes you mad dog LOL, more power to ya!!! 1 Outback Jack reacted to this Share this post Link to post Share on other sites
FORD_MAN 1,026 Posted March 21, 2014 Yay my webber might flow 264-267cfm, Looks good Sean, I might have to see if the speedways on when I'm over in Albany at the start of May for my brothers wedding. 1 Clevo120Y reacted to this Share this post Link to post Share on other sites
Clevo120Y 815 Posted March 21, 2014 That would be good mate, great to put faces to forum names. Share this post Link to post Share on other sites
Clevo120Y 815 Posted March 21, 2014 Last race meet is the 20th of April, I just looked it up. If you get some free time while your here send me a message and we might be able to catch up. Share this post Link to post Share on other sites
Clevo120Y 815 Posted March 23, 2014 Well had an interesting day yesterday, Wombat was running late so we didn't have much time for the carby change and all the other bits and pieces, so I put the carb on and when we fired it up she was running like shit, wouldn't idle and was generally average so instead of spending time going over it and tuning we just deceided to put the original carb back on and just use the mod aircleaner and the carb top I made, the air/feul ratio guage hadn't arrived during the week so I had no accurate tuning tool anyway so sticking with the carb that goes fine was the best way to go. I put a few more degrees advance in the timing and then chucked it on the trailer, we were late getting to the track LOL. At the track it was drizzling and the surface was new and very slippery, we dropped the tyre pressure in the back to 23psi and upped the fronts to 28psi and Wombat was off for the first heat, the car was still very loose and a couple of laps in I could hear a nasty miss in the engine, was gutted. When he come in checked it over and noticed a lead on the dizzy cap was loose so clipped that back down and thought that was the problem. Dropped the tyre pressure in the rear to 22psi and left all the clay in the wheel arches in there for added rear weight for heat 2, The car seemed to be a bit better in the handling but still loose plus that misfire was still there, the car sounded terrible and I was starting to stress on what it could be. When Wombat returned he said he couldn't really notice a problem or hear the misfire but I could, he also said that the car had plenty of power but he couldn't use any of it because it would break into wheelspin bad. Pulled the rocker cover off and checked for bent pushrods etc etc but all was good, went over the whole engine looking for vac leaks and all was good, so I pulled 3 degrees of timing out to start again and put it all back together for heat 3. What a dramatic change!!! Still loose in the turns but a fucking jet down the straights and it was on song, sounded brilliant, crisp and clean. Wombat was up in second but got turned around by a serial mongrel that dose it to everyone that he can't get past, I was spewing but also pumped that the engine was singing again, so he come last in that heat but the silver lining was he got a number of laps by himself to really throw the car around and get into a groove, Wombat has only been racing for a couple of seasons and still getting into the flow of it. So it goes to show what a couple of degrees of timing can do to the performance of an engine. Final started right at the back of the field and moved through the slower guys quickly and was in the main group of 7 up the front, still really loose but always made up ground on the straights, was a brilliant race and finished in the 7th position which is not right up the front but the top 7 were the cars within a 1/4 of a lap of each other and lapping everyone else on the track. So the car has power in spades but can't get it to the ground so that setup is what we have to work on now. 1 gerg reacted to this Share this post Link to post Share on other sites
slydog 7,873 Posted March 23, 2014 You pulled timing and it went faster...lol When will that ever happen again.Just shows how important it can be though. 1 Clevo120Y reacted to this Share this post Link to post Share on other sites
gerg 10,871 Posted March 23, 2014 Engines with short rods/long stroke have very little piston dwell time so ignition timing is critical in that short window you have to play with. What fuel is he running? Some engines can actually go backwards with power before even starting to ping, I've had that on my LPG Corty, when you could hardly tell the difference between too advanced and too retarded (never pinged, ever). It's a very subtle difference but with too advanced, the engine feels a bit rough in the car, like you can feel the power pulses much more. Retarded feels smooth and doughy, and exhaust note gets a bit louder. So the age-old method of "bump it up till she pings, then knock it back a bit" doesn't apply necessarily for all engines and fuels. Sounds like you're pretty chuffed at the performance thus far, and I would be too... And you still have more to come! 1 Clevo120Y reacted to this Share this post Link to post Share on other sites
wagoon 2,429 Posted March 23, 2014 Running second till someone else spins the car sounds like a front runner to me. Well done on the work so far and thank you for openly sharing the info. 3 slydog, Clevo120Y and eattsie9 reacted to this Share this post Link to post Share on other sites
Clevo120Y 815 Posted March 24, 2014 Yeah I thought I would be able to sneak some timing in but no it didn't like it hahahaha, 10 to 1 comp 98 fuel and crow 672 cam, but limited to stock rockers, stock exhaust, stock intake, unbalanced bottomend, stock head but can do valve seats and back cut on the valve plus a little throating when putting new seats in. The race we were running second in was a heat so only half the cars on the track, the bloke that spun him is a consistent top 3 finisher and probably could of passed cleanly it is a very quick car but he always seems to be involved when cars turn around. I truly think our car is in the 4th 5th 6th 7th group of cars in the southwest as that group is tight racing everytime and they swap around those positions every race, it only takes 1 bad corner in that group to loose a position or 2 so is great racing, the front 3 cars are just that step ahead but if we can sort the traction issue I think we can compete with those blokes. This car is by far the fastest carby car in the area without doubt and yes there is more to come but as Ando has said to me if I can't get the power to the track it will be for nothing and I think the car will be slower with more power because it breaks traction earlier and will go nowhere. Anyway I am happy with how the engine is performing and sounding but car setup is now a priority. 1 slydog reacted to this Share this post Link to post Share on other sites
ando76 4,354 Posted March 24, 2014 Don't panic my friend we will get your gains to the ground. Its just a matter of us getting the percentages right. Can't have those hard fought motor gains going to waste. 2 slydog and Clevo120Y reacted to this Share this post Link to post Share on other sites
Clevo120Y 815 Posted March 25, 2014 Yeah cheers mate, I get the car back in my workshop tomorrow to sort this carb out and put the air/fuel ratio meter in, if I can get it down to Nevs to scale it I will post up the results of that. Things that limit us in the class are.. No ballast but moving weight that's in the car already is allowed, plus I don't see an issue of adding extra bar work for "safety" plus maybe some reinforcing plate under the fuel tank etc etc No stagger in the tyres, plus stagger won't work because the cars have to go in both directions and the decision of which way the race will run is made by a coin toss in the shoot so you couldn't predetermine the direction anyway. No adjustable shocks, we can only use standard style sealed steel tube shocks, doesn't mean you can't get a set valved to suit the car but it would have to be an allround setup or spend a fortune getting a few different sets that we can swap over in the pits between races (not really an option financially). That's about it. Share this post Link to post Share on other sites
Jonathan Mark Davidson 169 Posted March 25, 2014 can remove weight to fairly easy if need be Share this post Link to post Share on other sites
Clevo120Y 815 Posted March 25, 2014 If any weight has to be removed I would say it's from the front end, don't know how much we can remove from there, it has a fibreglass bonnet but steel fenders, he put the steel ones back on because the full fibreglass frontend kept getting fucked up real bad and he was sick of patching it back up, might be the price to pay to be up the front. Share this post Link to post Share on other sites
Jonathan Mark Davidson 169 Posted March 25, 2014 If any weight has to be removed I would say it's from the front end, don't know how much we can remove from there, it has a fibreglass bonnet but steel fenders, he put the steel ones back on because the full fibreglass frontend kept getting fucked up real bad and he was sick of patching it back up, might be the price to pay to be up the front. with guards try to get ones that are only 1layer thick they flex and are very hard to crack i drilled many holed in my inner fenders to lighten my front up when i was racing along with the bumper (then one layer of race tape to cover them) can even remove the roof skin and skin in fiber glass 1 Clevo120Y reacted to this Share this post Link to post Share on other sites
ando76 4,354 Posted March 25, 2014 Most classes allow for the removal of all sheet medal forward of the strut tower, doesn't sound like much but every little bit helps. I am starting to get real anal about front weight as I want to improve me rear percentage to so that I can run less ballast early and then add ballast as the track slicks off. As HBWC has said the lighter fiberglass panels are the go because they flex - I have actually just gone to a one piece fibreglass front end (guards and bonnet as one) as it has allowed me to remove a hell of a lot of front bar work and I figure it will stop the guards from breaking where they mount to the body. It will also make it easier to work on the engine. Afco and many of the other brands make steel body shocks in various valve rates and they are as cheap as chips. They also make stock springs in different poundages as does King springs and they are Australian. Some of the Supercar boys were running King springs and I have run them and find them very good. The key to getting bite at the rear and stopping wheel spin wheel be softening the rear springs and increasing rear percentage. You may also have to groove the tyres a little to help them bite, if that is allowed. Lastly if you want a good book on chassis and suspension set up you can't go past 'Dirt Track Chassis and Suspension' from HP Books. It is a yankee book but the info is good. The ISBN is 978-1-55788-511-1. 2 Clevo120Y and Jonathan Mark Davidson reacted to this Share this post Link to post Share on other sites
Jonathan Mark Davidson 169 Posted March 25, 2014 grooving is aloud well it was 7 years ago so where winter tread tyres (no studs of coarse) 1 Clevo120Y reacted to this Share this post Link to post Share on other sites
Campo 869 Posted March 26, 2014 In street stocks all the front sheet metal must remain and they must be a passenger replacement shock. So no afco/pro etc. Cant go past Koni shocks imo. Grooving of tyres is allowed. Also, what tyres is he running Clevo120Y? Share this post Link to post Share on other sites
ando76 4,354 Posted March 26, 2014 Gee that kinda sucks - what happens if you have a good front ender - the car is useless or you have to destroy another XF to make yours whole - there bloody isn't many good ones around anymore. With no name brand shocks allowed that makes it kinda hard. weren't bilstein shocks standard on XF 50th anniversary???? Oh well as long as you can change the springs good shocks like Koni etc should be up to the task. Man why do they make it so hard - I'm glad I run modified sedans where at least you can make them handle like a race car should with coil overs etc. Share this post Link to post Share on other sites
Campo 869 Posted March 26, 2014 Gee that kinda sucks - what happens if you have a good front ender - the car is useless or you have to destroy another XF to make yours whole - there bloody isn't many good ones around anymore. With no name brand shocks allowed that makes it kinda hard. weren't bilstein shocks standard on XF 50th anniversary???? Oh well as long as you can change the springs good shocks like Koni etc should be up to the task. Man why do they make it so hard - I'm glad I run modified sedans where at least you can make them handle like a race car should with coil overs etc. Gotta do a cut and shut or reshell. Not many xf's getting around as racecars these days either, most people have upgraded to later models. Bilstein's and koni's are allowed because they're a standard replacement part. Only internally adjustable ones (must be removed to adjust them) You can do a lot with a good shock and spring package, could put you onto a mate of mine in melbourne that does koni's and king springs if you like Clevo120Y. His suspension packages would be in like 80% of top running street stocks australia wide. Share this post Link to post Share on other sites
Clevo120Y 815 Posted March 26, 2014 Thanks guys, great info. This is a hard class to go fast in because of the limitations. Campo that would be awesome to have another contact to talk to and he probably has a suspension/shock package ready to go for the XF once I give him the scale results. Tyres I don't know what he has but they are chuncky bastards hahahaha. I know that he has Koni shocks in the front. Share this post Link to post Share on other sites
Campo 869 Posted March 26, 2014 I'll message you his details later tonight if you like mate. Good tyres deffinately help, is he running 14" or 15" rims? Share this post Link to post Share on other sites
