18RGEU conversion help

[dale30]

Hi All

Have just aquired an 18RGEU to fit into speedway car that is currently running an 18R.

I have a fresh race prepped 18R bottom end and i cant afford to rebuild the RGEU.

1. Do 18RGEU have flat top,dished or domed pistons.?

2. Does the RGEU head and timing chain setup go straight onto the 18R bottom end. If so what would compression ratio be with flat tops.

3. No loom or ECU.! are these available or is it better to convert to carby.

4. does anyone have these items for sale.

[Screamn_Sleeka]

-1: Do a search, this is always asked

1: All 18RG~'s have domed pistons as they have hemi chambers. also 18R rods are shit.
18RGEU have the worst of the domed pistons 8.5:1 , the first gen, 18RG has the best 9.7:1.

2: Yes the head will bolt on, but the oil pump and dizzy wont be right, so u need to use the RG aux shaft. SO, jsut the bare 18R block and crank, swap EVERYTHING else. 18R pistons will make the ratio like 7:1, buy forged ones and a turbo?

3: All engines are better to convert to carbs if u dont want to spend 3k+ on a real fuel injection system.

4: Many people, ebay etc.

[dale30]

Thanks for that. i am trolling the searches as well.

At 8.5:1 it would lend itself to supercharging.
Any idea how much boost this motor will take safely for constant 6500rpm.

[DQIKST]

a pair of trumpets on 44mm solex

i can hear the birds humming already

DQIKST

[Screamn_Sleeka]

The 18RG motor has been sucessfully turbo'ed many times.
I think the weakest part would be the stock pistons, so maybe 10psi? i think that would be safe anyway. But it would be a good idea to get forgies.

[Svarky]

Hey mate I might have some useful info for you, its not to difficult to set up your 18RGEU with the old (but fully programmable) GM Delco ECU. You can pick up a loom & ECU for less than $100 at a wreckers (JE camira) and get all the sensors fairly cheap. The only real difficulty is adapting the Camira Ignition module to the 18RG.

Notice the MAP sensor attached to the top of the inlet manifold.

Below are some picts of my 18RGEU in the good old XT130...