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

[73GTV]

Hi guys. I've been absorbing info on this thread for years, I hope there are still a few lurking around to answer a question. I have an 18rg, very earliest motor with 9.7 pistons in a lotus 7 kit. I've blown the head gasket so it's coming out to get a refresh and I'll mate it to the spare 88253 head I have (I'm hoping the head is serviceable). I'm hoping the bottom end is still in tolerance so I can hone the block and put in new rings and all new bearings. What's the experience with these motors changing to ARP rod bolts? Do you think I need to get the rods resized if I do? Am I safe to reuse the old rod bolts?? I know the originals have been untorqued and retorqued at least once as bearings were changed some years ago.
Thanks Dale

To verify the specifications on the limits:
http://members.iinet.net/~stepho/man.../engine%2018R/

Are you going for the head to be re-surfaced?

Are you going to check the block and possibly have it decked?

Because Kameari has thicker head gaskets and if you do change out piston sizes they also can assist you.

Download their PDF of P45 and P46

http://www.kameariengineworks.co.jp/CONTENTS-2.html

[Dalerous]

Hey guys, thanks for the replies. Even though my 9.7:1 pistons are perfectly useable, I've decided to get some 92mm 10.5:1 pistons from Kameari to build a more powerful motor. They should arrive in a week, fingers crossed! Everything is going off to the machine shop next week to get crack tested and checked over. I've ordered a 0.050" head gasket from Kameari which should put compression ratio at 10.6, maybe 10.7/10.8 if the head needs a little skim to clean it up. The head I'll use is the 88253, it needs valve stems, it'll get a valve job and some porting.

I'll be using my original 40mm mikunis initially (and stock exhaust manifold), they'll limit power big time but it's what I have to work with for now until I find some 45 webers.

**Another question - I have cams from the 88253 head which ultimately I'll get reground BUT because I'm using the 40mm mikunis for now (which will limit power/rpm), I'm considering using the 88210 cams. Does anyone have experience using the 88210 cams with increased compression? Will I run into detonation issues?

Thanks,
Dale

[73GTV]

Hey guys, thanks for the replies. I've decided to get some 92mm 10.5:1 pistons from Kameari to build a more powerful motor.

Just remember that the larger the bore, the thinner the wall and that could become porous. The way 92mm were used in the old days was with cylinder liners pressed down onto the ledge that the machinist made for a seat for that new liner to rest against. Those liners were into the water jacket.
The inner diameter was 92mm the outer diameter was much larger I'm guessing now about 95mm. Racing application only.

(Just my opinion Only) Look at the diagrams of the cooling system or lubrication system to give yourself at least some image of the material to be removed and take some time to measure the deck of your block.

Someone is gonna have to make the call on what will or will not fit in order to make them fit properly. (The cylinder liner equals a sleeve)

http://members.iinet.net/~stepho/man.../engine%2018R/

[Dalerous]

Hi 73GTV
From everything I've read on these particular engines, 92mm bores have been done countless times without bore liners. Lately, I've read from a few people having done this 20-30years ago and still going without issue. 3.5mm definitely is a huge amount to overbore so it can't be without risk but I'm expecting it to be fine given experience of many others.

[73GTV]

Understood I have given my opinion. May you have a long successful build. I've only been doing my builds since MAY 3RD 1978. (My first engine build in Japan) but had personally only run across three each porous blocks. with bores less than 92mm. Those failed due to rusted coolant passages.

[73GTV]

Carboy magazine November 1981
How to build a 2.4 18RG
Page 77!

So the advice I share proves a point.

You are welcome!

[Dalerous]

That's excellent 73GTV! Glad to hear your interest with these engines has spanned decades. I really hope that my block (actually I have 2 thankfully) will be okay going out to 92mm.

[73GTV]

That's excellent 73GTV! Glad to hear your interest in these engines has spanned decades. I really hope that my block (actually I have 2 thankfully) will be okay going out to 92mm.

I only wanted to make sure that you were aware of that issue. also, look around for the 8R engine blocks 11401-39086 is the part number for the 86mm Block.

These NOS Blocks come up for sale after being stored in some forgotten warehouse, so keep a lookout for them. That block can be bored up to accept your standard 88.5 stock pistons.


Part Number: 11401-390205 18RC, USA Part Number

18R-U block 11401-39207 Japan Part Number

18R-U block 11401-39285 Japan Part Number are All the same block two minor Differences. Diptick mounting point and the engine number stamp can be used to replace a worn-out 18RG Block.



From August 1978 - to June 1981 18R-GUEU Replacement Block Part Number: 11401-39247


From June 1981 only 18R-GUEU Replacement Block Part Number: 11401-39375

From August 1977 August 1978 Only: 18R-GU Replacement Block Part Number: 11401-39246

These are the part numbers that I would research for NOS stock items.

Now why am I going on about all of these numbers, This was the search method that I just used and have just purchased a NOS 18R-C Block on Ebay this morning. Just a heads up: My Example

Toyota Cylinder Block Sub-Assembly Part # 11401-39205”
Compatibility:
See compatible vehicles
Sold for:
US $470.00

eBay item number:
224732027075
Seller assumes all responsibility for this listing.

[73GTV]

online search today:
From August 1978 - to June 1981 18R-GUEU Replacement Block Part Number: 11401-39247

https://www.monotaro.sg/p/14311755.html


TOYOTA MOTOR
(11401) Cylinder block SUB-ASSY
Be the first to review this product
Item #
14311755
Mfr #
11401-39247
Package Qty
1pc
S$2,999.00

[andrewzuku]

I've uploaded a scan of the JDM 18R-GEU Service/Repair Manual.

There's lots of cool stuff in there, including the ECU pinout, and specs like engine weight (166kg) etc.

Here's the link. The JPEGs are only 100dpi, but the PDFs are 300dpi.


Toyota Service Manual - 18R-GEU Engine

Sorry if I've dug up an ancient thread, but this seemed like the best place to put it.