coaster bus engine 20R & 5R

Submitted: Thursday, Jul 27, 2006 at 17:13

ThreadID: 36212 Views:5007 Replies:4 FollowUps:6

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Luke SA

G,day i have a 20R engine from a 78 coaster bus that had a 5 speed gearbox behind. A bloke wants to buy it but is a bit worried that it wont fit his bus of the same year.

The problem is, his motor is a 5R and has a 4 speed gearbox behind it, just wondering if anyone has had any experiene with these motors and could shed some light on it for me as he wants me to fit it for him aswell

Thanks in advance........

Cheers Luke

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Reply By: Eric Experience. - Thursday, Jul 27, 2006 at 21:06

Thursday, Jul 27, 2006 at 21:06

Luke.
If we asume that the20r is the same block as the 18r then I can asure you that it will not bolt up. I did a conversion from 5r to 18r and it was a major job with a special adaptor machined from a billet of steel, the end resolt was very disapionting as the performance improvment was negligable. it is better to reco the 5r The model with the 5r has 6.something diff ratio and the bigger motor has to rev very hard to go any faster. Another alternative is to buy a rusted out 80 model dyna and use the 5 speed and diff from that. good luck. Eric

AnswerID: 185701

Follow Up By: Luke SA - Thursday, Jul 27, 2006 at 21:33

Thursday, Jul 27, 2006 at 21:33

Eric,
thanks for your reply. I have not seen this 5r motor i am just going by what the owner has told me (i also dont know him as he had an ad in the paper looking for one of these 5r motors), he tells me the dip stick tube sits back a bit further and the distributor also sits back ao the side. Was this the case with your conversion. If it is then id prolly recon the 18 and 19R's are the same.

What are your thoughts on this?

Cheers Luke

FollowupID: 442586

Follow Up By: Luke SA - Friday, Jul 28, 2006 at 17:00

Friday, Jul 28, 2006 at 17:00

Eric,
I told this bloke what you told me about the 18R conversion. He still wants to buy mine and is interasted in where and how much (aprox) this adaptor was?

I sugested for him to recon his 5r but he tells me he cooked it and has cracked the top of the block so its not worth rebuilding.

If he can get hold of a 5r cheap enough i think he would buy it and rebuild it so if anyone in adelaide or close by knows of one please let me know if you want to sell it and i will let him know

You can contact me on (08)82805707

Cheers Luke

FollowupID: 442790

Reply By: Eric Experience. - Thursday, Jul 27, 2006 at 22:02

Thursday, Jul 27, 2006 at 22:02

Luke
The 5r is a push rod motor with a sheet steel cover, the 18r is an overhead cam with a cast aly cover. The 18r was very common in coronas and hilux around 80's Eric.

AnswerID: 185715

Reply By: Mad Dog - Vic - Friday, Jul 28, 2006 at 17:12

Friday, Jul 28, 2006 at 17:12

Pity you were not asking this question a year ago when we had the perfect bloke here for you but he was banned for having too much fun

He has a 1975 Coaster which he put in a 22R out of a 1996 Hilux.

At the same time he also put a 5 speed box in out of another toyo vehicle but from a different supplier which left him needing a bellhousing that I think was supplied to him from Castelmain Rod Shop www.rodshop.au

Some manipulation and massage was needed but I do not think it was to hard. (read; welding brackets and shortening of tailpipe, diff etc.)

J & D Auto Engineering in Melbourne (03) 9354 9310 do conversions like this daily. Frank would be worth a phone call.

Or post this same question on overlander, you might find the banned one lurking there.

Good luck, we spent a week in the high country, a while ago, and a 22r with a 5 pps box in a 75 coaster can really go places. Most forumites here would be surprised.”

MadDog & Company

AnswerID: 185869

Follow Up By: Luke SA - Friday, Jul 28, 2006 at 18:01

Friday, Jul 28, 2006 at 18:01

thanks Ray i have let the fella know about those places but now its up to him to do anything about it.

I have also read a couple of threads about that bloke that was banned but unfortunately his motor was a bit later model than mine and he changedthe gear box aswell, i think this pensioner wants to spend as little money as possible........always the the way though

I put a holden 186 in a 1978 coaster a couple of years ago for a friend of my dads, was a bit of mucking around, with engine mounts having to make them and modifying aircleaner and accelerator linkages but its amazing what you can do with a mig grinder and imagination.

I dont really want to do anything as big as that at the moment, espesially for someone i dont really know, too busy at the moment

Thanks again Ray

Cheers Luke

FollowupID: 442803

Reply By: Eric Experience. - Friday, Jul 28, 2006 at 19:34

Friday, Jul 28, 2006 at 19:34

Luke.
5R motors are easy to find, they were in dynas , stouts and coronas, you should be able to get hold of one cheap because they all rusted. Failing that I have about 4 motors in stock in melbourne. Eric

AnswerID: 185892

Follow Up By: Dave198 - Friday, Jul 28, 2006 at 21:26

Friday, Jul 28, 2006 at 21:26

Fairly sure the 5R was used in quite a lot of toyota forklifts too.
There were minor differences in the 5R's. I had quite a lot of parts for them many years ago , but forget the differences. I think it was where the ancillaries bolt onto was one area they were different.
Dave

FollowupID: 442846

Follow Up By: Luke SA - Saturday, Jul 29, 2006 at 21:07

Saturday, Jul 29, 2006 at 21:07

Eric,
the bloke (John) that wants a 5r motor says he cant find one here in Adelaide after ringing around but wants to know if he could get in contact with you as you have said you have 4 of these motors. So if possible could you either give me a call on number above and give me a contact no. or leave a number on here for him to call you on, its totally up to on which way you go about it.

Cheers Luke

FollowupID: 443002