Topic: Dowel pin in engine block - important?

[Franky]

Hi guys

Putting my engine together after a rebuild and to my surprise, one of the dowel pins in the engine block is missing! See image below. I'm sure it wasn't there when I took it apart. It's the left one that's missing.

Question: How big a deal is it? I know it does something with the oil pressure, but I'm not sure how important it is or exactly what it does.  It ran pretty good before the rebuild...   

Let me know if I should spend time on finding one or just go without it.

[dave500]

gday franky long time no post,,thats not only an alignment dowel it is also an oil feed restrictor to the top end(cam/rockers etc)you must have it,without it youll most likely lose oil pressure at the crank big end and mains.

david silvers list it as a discontinued part,youll have to find one though,dont go this far and leave out a simple but very important thing like an oil control restriction.,its part #12238-323-000.

[MRieck]

To answer the question...yes...it is a big deal. Get one.

[killersoundz]

I was getting worried there for a second because my cb750 doesn't have one of those on the end like that but then I realized that's not a 750 motor

[lucky]

I was getting worried there for a second because my cb750 doesn't have one of those on the end like that but then I realized that's not a 750 motor

Well the OP did not even tell us.

[lucky]

Hi guys

Putting my engine together after a rebuild and to my surprise, one of the dowel pins in the engine block is missing! See image below. I'm sure it wasn't there when I took it apart. It's the left one that's missing.

Question: How big a deal is it? I know it does something with the oil pressure, but I'm not sure how important it is or exactly what it does.  It ran pretty good before the rebuild...   

Let me know if I should spend time on finding one or just go without it.

Lets see....hmmm Honda drilled a hole with a certain depth and certain diameter and then manufactured a special pin that goes into the engine block and it is a particular height. Setup,milling cleaning..

Nahhhhh just forget about it.  LOl....lol...lol

[the technological J]

i put an engine back together without one and it dripped oil from that side of the block so i pulled the engine to replace it and  tore the new base gasket trying to put in the cam chain tensioner assembly had to wait for a new one to come in, then snapped a ring on reassembly... so after the ring came in i accidentally tightened the head gasket on the wire i was using to hold the cam chain so i had to order another head gasket.... then i forget i sold the bike after getting it back together... moral of the story dont leave those out.. it sux

[Scott S]

 Did you check the barrels to make sure it wasn't stuck in there?

[Franky]

Thanks for your answers guys - even the sarcastic one ;-)

If I'm lucky it's like Scott says, otherwise I'll go to a guy nearby with a parts-bike. I'm sure these things aren't stuck and a pain to get out...

Dave: yes, it's been a while. Got a kid now (boy of course) and I've been busy customising one of my small 50cc's. Lots of fun, will post some pics later... I suppose those things are sohc too!

[Franky]

Oh! And sorry for forgetting to tell you its a CB550 K3 engine...

[dave500]

congrats on your new little SOHC enthusiast!

[faux fiddy]

Hi guys

Putting my engine together after a rebuild and to my surprise, one of the dowel pins in the engine block is missing! See image below. I'm sure it wasn't there when I took it apart. It's the left one that's missing.

Question: How big a deal is it? I know it does something with the oil pressure, but I'm not sure how important it is or exactly what it does.  It ran pretty good before the rebuild...   

Let me know if I should spend time on finding one or just go without it.

Lets see....hmmm Honda drilled a hole with a certain depth and certain diameter and then manufactured a special pin that goes into the engine block and it is a particular height. Setup,milling cleaning..

Nahhhhh just forget about it.  LOl....lol...lol

Until your head gasket fails, greases everything in sight and then all the other stuff that can happen  before you notice no oil in the cranckcase.

[the technological J]

unfortunatly that wasnt sarcasm... it really happened to me.... read my k8 project thread

[Romhog]

I came across this situation just yesterday. I take the engine block off and lay it on the bench and notice that I only had 1 oil orifice "dowel".... I checked on the floor, flashlight down the cam hole, and under each piston, nothing.  I haven't dropped the oil pan yet, I plan on doing that this week. Maybe I will find it in there after all but If I don't I will be more intrigued . I trust the service manual to what it shows, and it seems to show 2 but can't help but think, was Honda trying to regulate the oil pressure by only using 1 of them during manufacturing? My engine only has 20k on it and don't believe the block has ever been removed by previous owners. at least it looks like original seals, etc. Did anyone else run in to this situation where they only had 1?

Just curious. 

[bryanj]

Never, they always have 2 so if one is missing its been apart before.
Sometimes they stay in case, sometimes in block and they only go one way up. Same part from 71 500 to 78 550

[Romhog]

Thanks for confirming. I'm about to go pull the oil pan. If it's not there I guess I'll have to get one off ebay as that seems to be the only place that has them. Unless you know of a better place?

[Romhog]

and the truth shall set you free!! should have just waited before posting earlier 

[RAFster122s]

Rimhog, glad you found it...
Clean them well and keep it in a safe place...
At least it didn't disappear into the void where 10mm sockets and wrenches go...