Rebuild 18R cylinder head *with pics*

[Screamn_Sleeka]

Mike, do you think the air pump could give timbosaurus an better fuel economy with his different carby?

timbosaurus, does ur 32/36 have a fuel return line?
My engine really doesnt like starting when its already warmed up, although started perfectly when cold, i think this may be because the fuel left in the fuel line gets hot and vapourises, but i didnt think that happened untill more extreme conditions. Although i am still missing pipes and stuff, so its not like my carby could be expected to run properly.

[Screamn_Sleeka]

Mike, where is this pipe going?
http://img113.imageshack.us/img113/3418/untitled4he.jpg

[timbosaurus]

Mike, do you think the air pump could give timbosaurus an better fuel economy with his different carby?

hmmm... me not know. possibly. but i can sacrifice a bit of economy for simplicity

timbosaurus, does ur 32/36 have a fuel return line?

Nope... same as stocko.

My engine really doesnt like starting when its already warmed up, although started perfectly when cold, i think this may be because the fuel left in the fuel line gets hot and vapourises, but i didnt think that happened untill more extreme conditions. Although i am still missing pipes and stuff, so its not like my carby could be expected to run properly.

I'm far from a carby expert, so i couldn't diagnose the problem. But i do know that carby gaskets/floats/needles/pumps are not designed to last 30 years. Most problems with carby cars having funny symptoms like this can be fixed with a carby kit/tune and a check of all the pipes for leaks (like it sounds like ur doing).

On another note, i think the best bet for the exhaust is to get a set of extractors and remove any of the exhaust components of the emissions system. You can do this while still keeping the air pump setup and original carby.

Also, that clear hose on Mikes setup should go back into the inlet manifold before the carby. I don't know why they have this as well as the PCV valve. Perhaps it is actually to let air INTO the crankcase/head area while the vacuum is sucking air out via the PCV valve.

[18rc turbo]

Mike, that 16R dizzy sounds good, is it completly 100% bolt in?

i'm pretty sure i have a 16R dizzy in my 18RC, which would mean they are interchangable, this picture shows the adjustable timing thing (which i have been told actually fine tunes the vacuum advance, not the actual timing, although it is effectively the same)

[18rc turbo]

Also, that clear hose on Mikes setup should go back into the inlet manifold before the carby. I don't know why they have this as well as the PCV valve. Perhaps it is actually to let air INTO the crankcase/head area while the vacuum is sucking air out via the PCV valve.

I reckon timbo has hit it on the head there. if you take that hose off with the PCV valve hooked up, at idle you can actually feel the air being sucked in (at least you can on my motor)

[Screamn_Sleeka]

On another note, i think the best bet for the exhaust is to get a set of extractors and remove any of the exhaust components of the emissions system. You can do this while still keeping the air pump setup and original carby.

I would pay $50 for a set of extractors, but i doubt ill find some for that price.
But yea i see what you are say, should really ditch the whole exhaust manifold with its pipes.

Also, that clear hose on Mikes setup should go back into the inlet manifold before the carby. I don't know why they have this as well as the PCV valve. Perhaps it is actually to let air INTO the crankcase/head area while the vacuum is sucking air out via the PCV valve.

Yea that is what mine does, and i jsut realised that his air filter would be in his pass. guard so thats where it is going.

[Screamn_Sleeka]

Thanks for that pic 18rc turbo, it looks good, ill go and get one when ever i can.

Although, thats clear pipe we are talking about, i though it was to let gasses from the cam cover out (blow by), which is piped into the air filter to be burnt? I cant see why this pipe would suck in???

[mike1980ra40]

i'm pretty sure i have a 16R dizzy in my 18RC, which would mean they are interchangable,

they are indeed, and that picture you've shown is what i've got and will bolt on to an 18R
without a drama.

[mike1980ra40]

Thanks for that pic 18rc turbo, it looks good, ill go and get one when ever i can.

Although, thats clear pipe we are talking about, i though it was to let gasses from the cam cover out (blow by), which is piped into the air filter to be burnt? I cant see why this pipe would suck in???

that clear pipe replaced the s shaped pipe that went to the original air cleaner. its a breather
for the engine and blows out gases to be reburnt. if you take it off and put a clean white rag
over the hole and run the motor for 5mins or so you'll see a fine mist oil on the rag and that is sucked into the carb, my my clear pipe goes nowhere. thats why my last sniffer test was so
clean. the only thing going through the carb is air and fuel, no recirc exhaust or engine oil
sucked thru the breather.

[Screamn_Sleeka]

Hey Mike, can u confirm that what is giving you better fuel economy is the cam cover - air pump - manifold pipe setup?

And does anyone understand how the 17670 valve works? what controls it?

timbosaurus, did u notice and abnormalities to ur 4th cly? possibly from it having the air pump pipe?

[mike1980ra40]

Mike, where is this pipe going?

that hose goes the the Idle up, (throttle positioner)

[mike1980ra40]

Mike, do you think the air pump could give timbosaurus an better fuel economy with his different carby?

I'm pretty sure it would, as it does with mine having done quite a tests with the belt on
then belt off etc. it certainly would hurt to try it out.

[timbosaurus]

Both my dizzy's have the adjustable knob as below.



These are standard 18R distributors. Are these the same as the 16R dizzy's mentioned above? Or am i missing something?

As for the pipe... the PCV valve is to let the vapour out of the crankcase/rocker cover area. It has a valve because it only wants to suck gas when there is no vacuum in the manifold (ie: WOT when mixtures dont matter much). I think the clear pipe with no valve on it is purely to let fresh air back in to replace the vapour sucked out.

[Screamn_Sleeka]

Im getting very lost, the air pump pipe in the manifold is coming from the air filter?
Air Filter - pipe - air pump - pipe - 17670 valve - pipe - 4th cly manifold.

Are we saying that 4th cyl is leaned out, basically running the engine on 3clys? But pumping enough air into the 4th cyl to keep it going with out disrupting normal enigne turning?

[mike1980ra40]

Hey Mike, can u confirm that what is giving you better fuel economy is the cam cover - air pump - manifold pipe setup?

i'll try ..

its a combination of several things: removing the exhaust part of the emission system,
replacing that with a 2" system and ultra flow muffler, having the optical ignition (4 degrees
BTC) and running on Premium ULP and also making up my own pod filter setup so that the
engine is getting the air it wants. air pump is (fairly certain) giving an extra amount of
air and by that it is reducing the amount of secondary throttle use.

another factor is the way i drive as well, change gear at around 3500, having extra stiff
springs on throttle links so I can rest my foot on the peddle and the peddle supports my foot. that helps keep the car running at a constant RPM.

hope all that makes sense