The 18R-GTE reference manual ...

[timbosaurus]

No different to any other car mate.

Unless you wanna run injected LPG, you just gotta setup the mixer/tank/lines and tune it.

I think "18RC turbo" on these forums is running an 18RG turbo on LPG, and it looks very neat and makes good power.

[**ta22**]

Thanks mate, I have sent him a PM for more info.

Has anyone heard an update of his car as his thread ends last year. Looks heaps neat.

Do you think the engine would have to be built for gas? stainless valves etc?

Probably a dumb question, but why haven't more people done this conversion? is you don't need to have carbies or injection which makes it more straight forward, and its cheaper to run!

[timbosaurus]

Thanks mate, I have sent him a PM for more info.

Has anyone heard an update of his car as his thread ends last year. Looks heaps neat.

There will probably be some pics of it in the "Picnic at hanging rock" thread... he brought it along.

Do you think the engine would have to be built for gas? stainless valves etc?

You don't need to specially build the engine for it. A well setup LPG system is actually good for the engine because the gas doesn't wash the oil off the bores. I'd say the valves would only be the weak point if the tune isn't right.

Probably a dumb question, but why haven't more people done this conversion? is you don't need to have carbies or injection which makes it more straight forward, and its cheaper to run!

I guess the main reason is that not many people want to run straight LPG (duel fuel is a lot more practical... especially if you run outta fuel ), so LPG adds complexity.

It's not cheap either... A simple LPG setup used to be $1500, but with the $2k rebate, most shops will now charge $3000 unless it's an off-the-shelf AU falcon setup

Not many of us do heaps of k's in the celica's, so not much saving.

The main reason to do it would be engineering. LPG burns cleaner... some engineers wouldn't even need it tested.

Cheers,
Timbo

[**ta22**]

Thanks Timbo!

[o_man_ra23]

From what I can tell, running LPG in a petrol engine is similar in issue to running unleaded in a leaded motor. That is the lubrication that the lead used to provide to the upper cylinder (read valves and valve guides) is greatly reduced, and thus they run dry and wear quickly. To solve this people would put in hardened valve seats and bronze valve guide liners, and in extreme cases stainless valves (which are never a bad idea as they resist burn better).

I would hazard a guess, that Timbo's theory is half right, in that the seats and valves should cop it fine, but the guides might be a struggle. Even though the guides in the 18R-G's will happily cope with unleaded, LPG may be pushing it too far. I would consider going stainless valves and bronze guide liners for the sake of not worrying about it, as pulling an engine apart after a build is just depressing, and for the cost, is it worth the risk?? (about $12 to 14 a valve for stainless, not sure the cost of bronze guide liners, not too dear I don't think)

Another thing I got told from a semi-reliable source (so would research further before beleiving) is that due to aluminium's porous nature, LPG degrades the head from the combustion chambers out (as an example, alloy wheels need to be painted on the inside otherwise your tyres will gradually leak out). Again, research that further first, as my source was only partially reliable.

As for turbocharging LPG, it's been done many times before quite successfully, as you say, LPG has a higher octane rating so it will take the extra combustion pressures with ease. So if your going to do it, I watch with interest for the results.

[LTJET]

In regards to all custom turbo setup.how much has your exhaust cost you guys including manifold etc etc?

[o_man_ra23]

Manifold and dump cost me about $200 - 300 to make, including purchasing all flanges and mandrels. The exhaust itself I got secondhand for $100, and I anticipate another $100 to have it all mated up. I did manage to get a lot of the required pipework from metal bins and the like though, and have done ALL the work to date myself (apart from machine the flanges flat after making the mani/dump)

If you are going to throw cash at somebody to do the work for you, expect to pay a lot more...

[SillyCarS]

i would expect around $1100 for a fully custom job on a 6 cylinder from a workshop, just for the mannifold, thats no frills, ie no heat coating etc

4 cylinder maybe $900?

[LTJET]

Yeah i'd love to have the skill and tools to make my own exhaust etc but unfortunately this wasn't blessed apon me. hehehe.
I got quoted $2k today for the custom manifold, dump pipe, T3 turbo flanges for the turbo as well as the rest of the exhaust in 2.5" mandrel bends but not sure if this is too much or not...

[o_man_ra23]

Not too bad considering its all mandrel bend gear, which is very labour intensive. If you go with it, make sure they are making the manifold with steam pipe and steam pipe bends.

[LTJET]

I'll find out if there's any difference in price to do that. Thanks for the tip Owen!

[timbosaurus]

Has anyone found a decent way to improve oil pump performance in an 18RG yet?

[The Witzl]

Has anyone found a decent way to improve oil pump performance in an 18RG yet?

This is a good question, and one that has plaigued me for a while.
With the engine that JMR has built for me, he has done some work with the sump to assist in avoiding oil surge. I cant advise exactly what, cos i havent seen the engine yet!!

Something else that was advised by a few guys who used to play with 18RG's back in the 80s and 90s is to improve oil drainage out of the head. Apparently a LOT of oil pools up in the head (around the camshafts) and doesnt drain back to the sump quickly enough. JMR also mentioned this as something he identified on the 3TGTE, and IIRC on his 3TGTE he "tapered" the drainage hole to assist in draining oil back to the sump. Im unsure if this was done to my 18RG.


The only other thing i can think of doing is finding some other oil pump gears that are talled and machining them to fit the 18RG pump housing, and add a thicker spacer. Of course this is pretty much a "trial and error" massive ordeal.

Other alternative - DRY SUMP?



LTJET - $2000 for the turbo mani, dump and full exhaust is pretty good. Usually you will pay at least $800 for a mandrel exhaust alone...


MnToyGuy - I've heard reports that you can use the early 22RE throttle body on the 18RGE. I havent tested this out myself... but I have thought of doing this because i have a feeling that the stock 18RGE TB is a little on the "large" size for a 2L NA engine.



Just an update on my 18RGTE saga...... engine is built now, but i still wont be doing much for a while. Im still paying off silly debts from years of being a young idiot, and until they are sorted im not allowing myself to play with cars.
In the meantime, im going to do the cheaper things... like clean up my engine bay, paint all my manifolds and engine bits, and rewire the whole car.

Maybe if im a really good boy my fiancee might let me buy an S15 T28 turbo, a manifold and exhaust, 2nd hand microtech, and some tuning.
Then i can start killing T series diffs

[MnToyGuy]

My guy is dragging his feet on the drawings for the "TRD" copy. I'll grab what he's got and try to verify/correct the measurements and get them to Ben. They are 2D right now. Ben said he can animate the geometry to check for interference/clearances.

The other issue is cost. They need to be wire EDM'd. Once we have drawings we can get bids basically worldwide. I brought the 2 parts into one shop and he said it was going to be AT LEAST $100 for each part at 25 sets. This is going to vary greatly based on tolerances. Obviously we aren't going to move many sets at $250-$300.

I had my engine shop port the oil return holes in the head. That'll help tremendoulsy. I also told them about the fill 10mm higher than the full mark. They checked this by marking the oil pan to the level the crank comes down to and filling to that mark (I had a mid sump). It turned out to be 6 quarts. Obviously the oil pumps is going to displace some of that and level will drop further with the filter and engine full. When I drop the pan, I'll take pics and post with measurements. Bottom line is you are very safe with 5 quarts.

If anyone wants to dig around here to maybe ID something with similar geometry to our pumps: http://www.toyodiy.com/parts/
Online part diagrams!

They don't go back to 1st gens, but you can see the RGEU diagrams here: http://www.toyodiy.com/parts/p_J_198...EMQF_2211.html

On the TB, I've got 5MGE on mine. It's going to need a spacer, but it'll work. From what if heard (read online), the 5MGE TB is 60 mm, like the 18RGEU. The 22RE is 58.5 mm and has the same bolt pattern. The 5MGE TB is a common upgrade for the 22RE guys.

See this thread for more infohttp://www.toymods.net//forums/showthread.php?t=1025&page=2

and here:
http://1stgencelica.com/forum/viewtopic.php?f=10&t=3099

I also have a genuine 18RGEU TB on the way and I can post comparison pics, once it arrives.

[ian]

Has anyone found a decent way to improve oil pump performance in an 18RG yet?

hi timbo
i had oil surge problems at winton
i found by putting an extra litre of oil in ,, the oil pressure still drops a little but not enough to do damage
ian