c20 build-r1 carb conversion-a15 overhaul-art of tuneing

[kiwi__boi]

hi there guys,just a lill insight on the van build, i had been toying with the idea of installing 36 or 38 mm R1 carbs to my A15 after doing a R1 conversion on a mates 3au AE70 coupe, i found them easy to base tune with only a quad vac gauge and re timed the motor. i believe going quad carbs or itbs opens you up to the option of higher revs and better throttle response but doesn't give you this without first taking other steps, things to consider are runner lengths and width, to my understanding simply the shorter they are the more response and increased rev up at the sacrifice of torque, velocity stacks also play a role in this area , port sizes, valve sizes and weight and valve response or range through heavier or double valve springs, flywheel weight reduction engine balancing and ignition upgrade, A fail on the 3au was that it was completely standard and tired, it ran well but due to the increased induction and load on the motor i think that the factory distributor and vac advance setup was inadequate and she wasn't quite puling as hard as she could low down or high up. i have put together a kit for my A15 build which is basically a rebuild bottom end with race bearings only for now, lightened fly wheel and double diaphragm p-plate with a press bonded super duty clutch ,i believe its somewhere around the 1300kg range for clamping pressure so i can drop clutch and garentee either wicked launch without slipping or a busted g-box or diff,( mx5 rear sub frame and air-shift 6 speed box to come later on) , as for the head im experimenting with a port match to valve size ( for now valves are just standard recessed ,over size stainless valves to come later with brass seats for e98) i kept the intake roughly 110mm in length with room to play for rev or torque gain, double valve springs and still looking at upgrading the rocker setup but still undecided what road to go down there, silicon brass valve guides also, I have since added air fuel ratio tuning to my tuning kit so i know what shes burning per cyl (x4) i have since thrown all factory timing gear out and replaced it with a mega jolt system and ze-tec edis ignition for its easily tuning abilities and so i can see whats really going on in there, the cam is an unknown upgrade which seems to of had a wicked power-band from about 4 to 6,000rpm+ (no rev gauge) running standard but that will later be replaced once computer goes in and i see where its lacking on the rev spectrum. i have added an RX3 oil coiler and Gilly style pulleys to run zetec trigger wheel an external oil pump for now with the intention of dry sumping on the next strip down along with high comp pistons and looking for an alternative crank to 'knife edge', i dont think simply bolting on and induction upgrade without internal work will gave you good results other than more fuel consumption and a wicked sound, eventualy i would like this moter smashing through al six gears at 10+ but its a build i know im gonna run into problems so im giveing the motor a 25,000km limit before strip down and adding more go fast bits every time, purely to find any problems within the motor so i can work away at them to make it reliable as possible, which to be honest it wont be but hey, it will always be fun to drive even being a van i hope to be up there on the track with other A series giving them a good run for there money,


ALL IN THE NAME OF FUN

[2 doors]

Hey cool build idea, love that its going in a van, sounds like you have a bit of experience on the engine building front, do you work in an engine shop or something?

[kiwi__boi]

cheers man and na not really, painter/paperhanger by trade. it all started when i got my first car, mkII escort panel van, it started with free flows and a bigger carb but i never really got a heck of alot of power just abit of fun, today i find it hard believe the cost of a rebuild , my mate recently had a big port 4age rebuilt for his ke30 but cost him up round 5g, lets just say if your in the know of good machinists you can do alot more than a standard rebuild for less than that, im not one to cheat and slam on a turbo or anything like that, i think there's nothing better than the sound of N/A motors screaming at ridiculous high pitches, im more curious in my own abilities to built a responsive motor than to just buy off the self parts for power, in every project money is a huge obstacle and that is why i try to source everything myself and try new things

[Kitch]

interesting direction. and sounds like a well laid out plan to me.
be interested to see finished results, keep the progress & pics flowing

you will get no argument from me about a screaming multiple throttle bodied N/A A-Series!

[kiwi__boi]

haha cheers, it is an addictive sound for sure, all too uncommon

[kiwi__boi]

does anybody know how to get in contact with user Fast4motion or can help me out with fitting a gilmer kit to my A15, i understand the easyist way is to modify a set from a __________. can anyone fill me in here?

[buzzy]

does anybody know how to get in contact with user Fast4motion or can help me out with fitting a gilmer kit to my A15, i understand the easyist way is to modify a set from a small block chev_. can anyone fill me in here?

[kiwi__boi]

cheers man i had a feeling it was from a chev but just wanted to be sure

[Bartman]

Craig at proparts napier can probably do you a pretty sharp deal on a set of those too.

[tlssunny]

its interesting as i know plenty of 20 plus year mechanics who wouldnt know how to tune a single carb and i know a few motorcylce mechanics (who know there shit) who wouldnt say tuning bike carbs to a "car" engine is the easiest thing they have every done, but yet from what you have said it sounds super simple, wonder why there arnt a whole heap of people advertising your skills