18RG electronic ignition

[joecoolmk2]

i doubt that very much. they all started out as single cams, which later were given a yamaha-designed twin cam head.

[joecoolmk2]

yamaha heads may be the connection you're talking of. who makes the heads for ford? i doubt ford could make a good twin cam head by itself no offence

[Screamn_Sleeka]

the 4AGE has the same boreXstroke as the 1.6 twin cam BDA, yes it is rumoured that this was copied, and some of the head design was copied. I dont know anyone that could tell u the truth.
Bill Sherwood goes into some of this is his site.

[Merudo]

the 4AGE has the same boreXstroke as the 1.6 twin cam BDA, yes it is rumoured that this was copied, and some of the head design was copied. I dont know anyone that could tell u the truth.
Bill Sherwood goes into some of this is his site.

yeah, that's what I was going to mention. I remember reading that some of the figures were the same as the twin cam BDA, but like Tosco has said, nobody would truly know if it as "copied" or not.


Doubt it...

[joecoolmk2]

well, they copy body shapes off other car manufacturers, just look at the 'mustang' celicas
maybe there is a hint of truth in there.

[ROHANVII]

there may be a theme going on there, they had a bit of a dabble with the twin cams. then followed it through with a mustang operating scale model, the RA28!
jokes, yeah guess noone knows, that would want to tell anyway! as toyota fans and they'd say no, ford fans say yes?!?!
i am still undecided, i guess its like religion, some people know for sure, some people say otherwise, some just dont care! but it is an interesting topic...
without trying to pry any props any from toyota, i might look into it abit more for my own amusment and a little bit of side info for general interest!
Check back later
ROHANVII

[ROHANVII]

hey guys, had a quick look at the site TOSCO suggested and i found this stuff:

source: www.billzilla.org/4agstock.htm

The twin cam 4AGE is basically a road going, mass produced version of the Ford Cosworth BDA twin cam racing engine. They share the same bore and stroke (81mm x 77mm), the same size valves (29.5mm & 25.5mm), and in some versions of the 4AGE very similar port shapes & sizes. When fully prepared for racing, they both produce similar hp figures at similar revs, so it would seem that Toyota has done an excellent job with them.
The parallels continue - The 4AGE is the first twin cam that Toyota made with a rubber drive belt for the camshafts, as was the BDA. The 4AGE was a development of the single cam 2A, 3A. & 4A engines, but I guess Toyota must have planned to make the 'A' series engine into a twin cam, perhaps again following the 'A' series Cosworth engines.

-------------------------------------------------------
source: http://www.billzilla.org/ae86stockpage2.htm
The engine is the fabulous 4AGE 1587cc twin cam 16 valve ... which is basically a copy of the Cosworth BDA race/rally engine. They share the same bore and stroke - 81mm x 77mm - and much the same size valves - inlet 29.5mm and exhaust 25.5mm. The exhaust ports are much the same as the BDA, but the inlet is a lot bigger, as Toyota use a device called TVIS (Toyota Variable Induction System) to improve the low to mid range torque.



ALSO CHECK OUT THIS LINK, DOWNLOAD THE FILE IT IS ONE OF THE COOLEST THINGS I HAVE SEEN IN AGES!!!!!!!!!!!!!!!!!!!!
http://www.billzilla.org/360drift.zip


i think im done for now, if anyone wants to know a bit more ill try find something else. oh yeah, once again ill just remind you im not out to prove anything i just think its interesting....
its funny, alot of asian (predominantly japanese) violinists, instead of playing for themselves and discovering their own style, they would learn songs exactly, and imitate another performer, and this is called the "suzuki" method.... suzuki also being in the automotive industry i thought it may have been ironic....
yeah, thanks for reading!
ROHANVII

[joecoolmk2]

yeah, i reckon that it's just a calculation really. i mean, why do manufacturers pick sizes like 57.5mm etc? i dunno

[ROHANVII]

yeah,
its a calculation for sure, different port, inttake/outlet size will obviously provide different flow and different pressures, the designing engineers need to determine, for instance with a 2L engine, how much, lets just say airflow, the engine needs to operate efficiently and powerfully and for the fuel to burn best, this would be calculated in relation to the fuel inlet sizings, fuel to air mixture and built accordingly..... then i think to get the strange sizings they would prob increase both the ports in scale with one and other so the ratio remains the same but still retaining the desired efficiency levels whilst increasing the power....
i think...


with this i think you'll find most engines will be common with each other anyway, because there is obviouly going to be a point where the max efficiency is reached for that engine, and all manufacturers want to get there. would basically lead them to doing the same calculations anyway, not necessarily copying the other designers, the principles of this type of engineering are the same no matter where your factory is, japan or britain....


i was doing engineering year at uni, but it was civil, mechanical had way too many concepts, such as this... i got a few mates still doing it and ill try and get a formula for you and try to explain it with the little knowledge of engineering methods i have left
in the meantime stay safe and away from speed cameras and busted parking meters!
thanks
ROHANVII (G.C.D)

[ROHANVII]

hey!
off the BDA vs. TOY topic, i wanted to ask somebody about ethanol in my `18RG, is this a big "NO"?
i've always put premium in it and it has always run really well, but only because i was under the impression that it only ran on premium, which i think might be abit wrong when i think of it...
so is ethanol in 18rg allowed and does it run on anything other than premium?
thanks, still working on getting those formulae!
ROHANVII