Unclejake Posted March 16, 2009 Share Posted March 16, 2009 Roller rockers and an increase in rocker ratio, followed up with a more accurate tune? Wouldn't increasing the rocker ratio just mess all the good work up and as a side effect break shit?Not meaning to be rude etc. as I do not know these old motors. Happily I can report that they do have the single most important ingredient known to Oldschool (apart from Pintos) PUSHRODS!!!!!! Yeah. Quote Link to comment Share on other sites More sharing options...
84_S12 Posted March 16, 2009 Share Posted March 16, 2009 Fuck I thought it was a common thing on the Holden Sixes as it helps bump up valve lift without changing the cam but then I guess if it's mashing valves into pistons and breaking drivetrain parts it's no use ay. Just thought I'd chuck a suggestion out there rather than tell a man how to build his car Quote Link to comment Share on other sites More sharing options...
EFI_LC Posted March 16, 2009 Author Share Posted March 16, 2009 Hi thanks for these, the tune would be a good idea I think, maybe I will take it in for a dyno tune, I am just worried they might change it though as it is really fighting out of its weight division at present. So far you have given some great ideas and I hope I have given you a decent picture of where I am and how I have overcome each one. I do have a cheapish roller rocker and it is 1.5 ratio. It is common to use 1.6 Chev rockers but as I am running std 186 hardened pushrods I may run risk of bending them. I am unsure of the max valave lift I can get from the head but I have just less than .5" actual at present. I was told the RRockers I have are not the best as they have too much sideways movement compared to say the leader 'Yella Terras' Knock sensors, how much money are they, and as I dont run a computer on this engine how would it retard the engine? I have a home made lambda which helps but doesnt give me an accurate reading I dont even have a shift lift light as I hear the engine and shift from 3rd to 4th at around 6500rpm BTW I used an angle grinder on the crank and modified it myself which may be helping this motor to spin more freely I have run the advance 2 degrees more and the vacuam advance is always disconnected plus the Dizzy has been limited on the mechanical advance, optimum is around 32 degrees at 3000rpm but as I dont have a timing light with an adjustable dial I dont actually know. Quote Link to comment Share on other sites More sharing options...
kyteler Posted March 16, 2009 Share Posted March 16, 2009 First things first. Congrats! That's an epic time in a 70's street car. Also, Torana's are the business and still being 202ci powered, big ups to you. I'm in awe of it right from the get go. Street legal drag tyres and a locker/welded diff/something to bind it up are what I would be looking at first and foremost. The problem there of course is that maybe that will break something but, that's racing in general I guess. The aid of a tight twin spinning diff, I would think, would get you into the 12's even if it was 12.999. Quote Link to comment Share on other sites More sharing options...
Spencer Posted March 16, 2009 Share Posted March 16, 2009 ^ yea fully agree One thing Ive got to say is dont use avgas the 100/130 avgas we get here is no good in your car it does stop detonation problems and may allow more advance. But in most cases will end up with less power (my cousins engine builder in taupo has dyno plots of his race bikes loosing power on avags). Get race gas If your keen (but would be cool to do a 12 on pump gas and street tyres). What 60ft's does it run dude? Quote Link to comment Share on other sites More sharing options...
Unclejake Posted March 16, 2009 Share Posted March 16, 2009 ^my cousins engine builder in taupo has dyno plots of his race bikes loosing power on avags I am stepping out of my boundary of knowledge here but:1) Racegas/Avgas is said to have a slower burn than ULP. I guess it is possible that it is not as much of an advantage on a very high reving engine like a motorcycle 2) Racegas permits a higher compression ratio without detonation. Motorcycles often have a higher compression ratio than car engines (I don't know why) so perhaps they needs to be even higher to take advantage of the race gas? Dunno. Just seems strange that so many guys use it if it isn't an advantage Quote Link to comment Share on other sites More sharing options...
drftnmaz Posted March 16, 2009 Share Posted March 16, 2009 locker!, the hilux lsd's are a joke, designed for mud use not road use. i'd be looking at a programagable ignition with load sensing then hit the dyno to set it all for a smoother power curve, might be the .2 seconds with that little bit more power in the middle range or somthing, i wont bother with Av gas unless you have the compression, cam and tuning to suit, just putting it in as it is will be a waste of time/money Quote Link to comment Share on other sites More sharing options...
EFI_LC Posted March 16, 2009 Author Share Posted March 16, 2009 Thanks people. 60' times are 2.0 - 2.1 0-100kmh in around 5 seconds Half track is mid 8's at around 85mph I can say its hard to comprehend this 202 doing the times its doing and believe me its raised a few eyebrows from people who have had quite a bit to do with them. I guess it was a package of various unproven parts that came together to create a pocket rocket. I very nearly gave up tweaking at 13.9 and thought well thats about as quick as it will go but persevered thank goodness. I really hope this can give others similar to myself the go go to try new tweaks to get a little more and also not to settle with what you have. Avgas I totally agree now after talking to my engine builder, the only advantage I can see is that it has lead and runs cleaner so I will stick with the mix i had 5 litres avgas to 20 litres 98 Now for the good news.... I am going forward with the Hilux and should have it in there mid-year, as family member is into 4WDs and modding them he can get his hands on just about any ratio and spool so looks like. Its my birthday soon and the family are going to do a whip around to pay for the diff conversion I AM going to try hard for a 12 second soon. PS. Its partly thanks to people in this forum who gave me encouragement earlier on and people like Bart who I have had many talks with at the drags and the other great guys at the drag racing that have put a smile on my face that probably wont go away for a couple of weeks. Graham Quote Link to comment Share on other sites More sharing options...
forced Posted March 16, 2009 Share Posted March 16, 2009 As far as the hardened pushrods go, my understanding is that they're hardened so that when they rub on the guide plates, they don't get worn away where they run. Nothing to do with bending. I'm sure that the likes of the big block chev, thicker ones are available, along with the guide plates. Or maybe it was clevelands? Anyway, bigger ratio rockers will give more valve lift. The knock sensor is only a monitor, the sensor itsself get from a wreck, it's only a fancy microphone, the Knocklink, I forget now the cost but there's a row of LEDs, when the top one comes on, you've got a problem so you lift your foot. Handy for setting the timing on the road, a dyno is a waste of time & money. Only good for bragging numbers, besides, it would need to be retuned for the road. Bast dyno tune isn't the best road tune. Oxygen sensors have limited life. If you get one from a late model car that's crashed, you should be OK. Those universal ones from the wholesaler are rubbish. Same goes for a wideband if the calibration hasn't been checked. Same for avgas, my car runs better on 98. Higher octane burns slower so needs more advance, without more advance you're loosing unless you've increased the CR. Bikes have (get away with) more CR due to more radical cams. Steve Quote Link to comment Share on other sites More sharing options...
Spencer Posted March 16, 2009 Share Posted March 16, 2009 ^ im no expert on the subject either uj but this was compared to 98 from BP. 1) Racegas/Avgas is said to have a slower burn than ULP. I guess it is possible that it is not as much of an advantage on a very high reving engine like a motorcycle you are correct with the slow burn, due to the opperating conditions the engines its intended to run in at low rpm, low compression, with constant speeds. Racegas is a different kettle of fish with its chemical properties I cant find any data sheets but it burns quickly like normal pump gas just with lead or other additives to bump up the octane. Also the 100/130 rating of avags isnt rated the same as say 100 octane automotive fuels is its actually works out lower. 2) Racegas permits a higher compression ratio without detonation. Motorcycles often have a higher compression ratio than car engines (I don't know why) so perhaps they needs to be even higher to take advantage of the race gas? Dunno. Just seems strange that so many guys use it if it isn't an advantage bikes usaully have more compression as they run massive cams compared to cars which gives them a lower dynamic compression ratio. So a higher static comp ratio is needed to compensate for the overlap, but they can still take advantage of the higer octane fuels with more timing I dont really know UJ I think its used as it is cheaper than race gas, also back in the day the gas at the pump was pretty average where avgas is very controlled and consistent. Man that took ages other people have said the same shit Quote Link to comment Share on other sites More sharing options...
Spencer Posted March 16, 2009 Share Posted March 16, 2009 locker!, the hilux lsd's are a joke, designed for mud use not road use. locker in his car would probably mean snapped axles, Hilux gets you away from this. If its used on the street a locker is shit, you can get torsen, propper ramped LSD's or detroit/spool options for hilux heads Quote Link to comment Share on other sites More sharing options...
Rusted Posted March 16, 2009 Share Posted March 16, 2009 Fantastic points already brought up. Locker/LSD, Sticky tyres, Weight reduction... How about removing the petrol tank and running with a Five liter tank for race day? Quote Link to comment Share on other sites More sharing options...
EFI_LC Posted March 16, 2009 Author Share Posted March 16, 2009 Ok I better explain where I started.... Budget fun come drag race DYO come club circuit come everyday driven car. I have spent less on this engine than some people spend on there weels and tires. Apart from the Carbs the rest of the engine owes very little and costs about what you would pay for a recon at a garage. The reason I used so many stock items was to reduce the overall cost, I had a set of 186 pushrods, I modded, std clutch, flywheel, crank and ignition for the price of one aftermarket part. Basically call it a backyard banger and to be honest I really don't want to throw alot of money at it. i know guys in Oz who have spent $20k+ to get these times from a 202 The car I bought for $1500 as a complete runner with a 'hotted' motor My engine/car has had about 3k or 5k with carbs spent on it for these times. I was lucky as the engine I bought with the car I sold off its parts to fund the new engine. I picked up a mildly worked injected engine with the Yella Terra and W55 for $600 (I tuned it for a 14.3 best 1/4) So you can see the money has got a lot of bang for my bucks entire car owes me around $7k- $8k The knock sensor sounds like a great idea. The tune I will pass on The dyno I will also pass on BP 98 FTW I have a 3.9 spooled Hilux or a 4.1 LSD to choose from already Weight reduction maybe I might remove the wipers and the fan Biggest weight reduction would be me on a diet lol I used my secret weapon on the weekend and gained .2 and it was free! People say it doesnt work usually or "how can that work" Quote Link to comment Share on other sites More sharing options...
forced Posted March 17, 2009 Share Posted March 17, 2009 You're obviously on the right track. I started off thinking that aftermarket parts were the way to go. Soon learned that stock parts are usually but not always better.Unfortunately you can't get roller rockers and roller cams/lifters for every motor as stock. Steve Quote Link to comment Share on other sites More sharing options...
Testament Posted March 17, 2009 Share Posted March 17, 2009 pretty much as other have said, change the diff - i would just use the 3.9 if you have it already otherwise go for 4.1 or 4.3 tyres- can you get some 13" or 15" rims that fit with stickier tyres as they are more available in those sizes? 13" with smaller dia. street/strip tyres could save you from changing the diff as it will shorten your gearing, although taller tyres have other benefits traction wise. drag slicks would almost certainly get you there but might not be what you want to do. more tuning - could give you a little more power/torque, but might not get you far enough. A bigger/longer duration cam might do it but would probably need to be done in conjunction with the diff swap to take advantage of more power at higher rpm. and higher rpm on stock parts is usually where trouble lies on old motors. cold air intake - making a fully ducted box with inlet at the front grille, wont get you there on its own but will have some benefit with lower intake temp and possible small ram air effect. weight reduction - cheapest performance increase there is, throw out everything you can/drill holes in it ala unclejake. suspension - drag racing suspension setup for more weight transfer, 90/10 shocks, softer springs etc. Quote Link to comment Share on other sites More sharing options...
84_S12 Posted March 17, 2009 Share Posted March 17, 2009 Surely you could be achieving a 1.9 second 60 foot time just by using sticky slicks and/or reducing wheel diameter? Quote Link to comment Share on other sites More sharing options...
EFI_LC Posted March 17, 2009 Author Share Posted March 17, 2009 Testament you are on to it... I bought some stock springs a couple of months back to soften the rear and spoke to my mate out at the track about doing this exact same thing on the weekend. Cold air box is probably a sound investment as well as a heat shield or wrap as these motors are non cross-flow and the exhaust sits under the carbs which warms them up. At every stop I raised the bonnet to let hot air out. Once again been talked about but never felt serious enough to do it until now. Thanks for reminding me. Slicks are beyond budget until I find some second hand ones but 14" are the go as 15" would struggle as this car originally was on 13's and 13's would make her scream plus I have no rims. I agree slicks should get me there on there own but I will go for the diff first. Quote Link to comment Share on other sites More sharing options...
RUNAMUCK Posted March 17, 2009 Share Posted March 17, 2009 Definately lose the belt driven fan. That will be theiving a few ponies. A mate of mine can get decent size electric ones for not too expensive. And that ducted cold air box for the carbs is a super idea. If you don't already have one, maybe a sheet metal sheild between the headers and the inlet manifold might help reduce the inlet temprature. I'd steer clear of that header wrap tape. I did mine, buyt it's a cunt of a job and it's crap. Plus I've read that it accelerates the degredation of the metal and shortens their lifespan. Quote Link to comment Share on other sites More sharing options...
Corndog Posted March 18, 2009 Share Posted March 18, 2009 should try this site, i would do it myself but dont know the weight http://www.dragtimes.com/horsepower-et- ... ulator.php just interesting to see... Quote Link to comment Share on other sites More sharing options...
EFI_LC Posted March 18, 2009 Author Share Posted March 18, 2009 should try this site, i would do it myself but dont know the weight http://www.dragtimes.com/horsepower-et- ... ulator.php just interesting to see... Here is what it reckons although I have used other sims and it says almost identicle but reckons it puts this to the wheels, i think the other one said I had 214.97 at the wheels Horsepower @ flywheel = 214.83 HP Quote Link to comment Share on other sites More sharing options...
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