For the love of a tractor engine: The life and times of the 18R-G

[o_man_ra23]

tried upgrading the alternator using teh Witzl's EA 85A method?? That would fux your voltage dropping due to big thermos. Also you should have a lower voltage at the coil, as that is what your ballast resistor does.

[timbosaurus]

The standard alternator is marginal, even with a standard electrical system. A lot of people upgrade to the falcon alternator (mentioned above) when they upgrade the stereo, the headlights, the cooling fans, or when the standard wires seem to be dissipating enough power themselves. So try that.

As for the coil, yeah, the ballast resistor should drop the voltage, but I assume you are either measuring on the high side of the resistor, or you don't have one installed... because it should drop the coil voltage more that 1 volt.

You seem to be loosing about a volt in the wiring, so running a dedicated wire would not be a bad idea. Having said that... 12.3V should be sufficient to energise the coil, so I'm surprised it is that causing the problem.

[GT1978]

Actually running a 70A EA falcon alternator at the moment. But it seems my battery has been a little over stressed over the last 12 months with the car being off the road most of the time.

Think I my tuning issue may also be due to too much compression. Haven't been able to get the adjustment I want on my cams and have decided to wait until I get my adjustable cam gears before I have another crack. Hope they don't take to long to arrive.
Glen

[old_school_jap1]

pulled apart my -88250 18RG, seems to have had dual valve springs put in. just wondering if somebody can tell me if these are 8.7:1 or 9.7:1 pistons?

[hosking1991]

if they are 9.7:1 it will say so on top of the piston

cheers luke

[Steve M]

Those pistons have odd casting rings on the top of them.
Are you going to take the rods out?
Check what the casting number is.

I'm thinking 9.2:1 maybe 18RG-R
There was another compression ratio, but I can't remember what it was. I know the pistons were 8823?. I think these pisotns had 8.9 cast into them, but I have only seen one set and it was a while ago. They were in an 18RG-R with an 88250 head and 88231 cams.

[o_man_ra23]

88230 pistons I had were 9.7:1
88270 pistons I now have are 8.3:1
Agreed with Steve, the casting rings up the top of those pistons are very odd, I have never seen pictures of 18R-G(add further extensions as required), or actual pistons with these casting rings.

Your bores also look like they could use a hone.

GT1978: too much compression is never an issue. Not enough cam overlap will cause the engine to lose power up top, but it won't cause it to cough, splutter or run rough, it will just run out of puff. Conversely too much overlap will cause the engine to run like a dog down low. I would suggest checking the overlap with a decent timing wheel and a dial gauge on magnetic base. I am sure I did a writeup on how to check it before, if not, check out the book '21st century performance' not only is it a great read, but it's full of useful information, and covers cam timing very well.

[Omegaman]

How essential is dialing in the cams on the three bolt 18rg cams (231's)?
If the rulel states to have the notches pointing north on intake and exhaust, then what gain can you get. I would think that only if you had adjustable gears will you see the dialing in an advantage. Only peace of mind would be achieved with doing this on a 3 bolt cam.
true or false and why? curious

[Omegaman]

What fuel pumps are you guys using on 18rgeu or similar.
Most interested in the surge tank applications, mostly the main pump.
I've picked up a Bosch 0 580 464 051 or 070 universal type(for comparison only).
which states it flows @160l/h 6 bar pressure.
Applications Vl inc turbo/senator V8's /jag..
would this be a good start for surge tank.
what should the lift pump then be?

[o_man_ra23]

Measuring your cam overlap as a basepoint will tell you how far out your existing setup is, and how much difference a set of adjustables could give you. It will also show you if your cams are a tooth out from each other, or a tooth out from the crank.

[JustenGT8]

pulled apart my -88250 18RG, seems to have had dual valve springs put in. just wondering if somebody can tell me if these are 8.7:1 or 9.7:1 pistons?

Hmmm as has been said they don't look like any 18RG piston i have ever seen, they also look to be a higher comp ratio than 9.7:1 as well.....you might have something interesting in there?

Comes stock with double valve springs.

[old_school_jap1]

Comes stock with double valve springs.

i was under the impression that -88250's didn't, but -88253's received them.
i'm suprised to hear about the pistons, looks like i'll have to take at least one out and have a looksie.

[JustenGT8]

could be as i never played with the 1st gen engines? could also be why none of us have seen pistons like that?

[old_school_jap1]

has anybody got some pics of a 9.7:1 piston at TDC? (there were some at the start of this thread i think, but they aint workin anymore)

[leso]

has anybody got some pics of a 9.7:1 piston at TDC? (there were some at the start of this thread i think, but they aint workin anymore)

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