Datsun Roadster Forum-311s.org

Regarding the pipe work from the top radiator cap to the expansion tank:

I 'd like to know whether the L shaped piece that is joined to the top of the radiator and links the pipe from the radiator cap receptacle to the pipe that runs to the expansion tank ALSO connects in to the top of the radiator. On my radiator IT DOES (I found this out when flushing my radiator out while it was out of the car) - but, using my own logic, this should not be the case.

Is this what the flow is meant to be like... ie. my L shaped pipe connector at the top of my radiator is actually a T shaped pipe connector that also runs into the top of the radiator? OR has whoever that re-cored my radiator last got it wrong??

Is the L shaped pipe link there just to keep the expansion tank hose clear of the fan by being welded to the top of the rad? Or is it a T piece that is meant to join the rad. cap receptacle to the top of the rad to the expansion tank in a 3 way split?

Anyone know the answer to this?

ps. Sorry for the essay but it's hard to explain...

John,

Tee or an L? I am a wee bit confused but that happens easily. There is a tee or an L however you want to describe it on the radiator itself. One connects to the overflow exspansion tank and the other goes to the filler on the engine block. As per the illustration below:

#61 goes to the filler on the engine and #58-60 go from the radiator to the expansion tank. It is a 3 way split.



Hope that makes sense to you.

Steve

The T fitting serves a purpose. It is to let the air escape out of the radiator so that you can have a full cooling system. As a tip, park the car downhill for the final fill. You can usually add just a little more that way.

Great thanks for that. As I understand, the piece I'm referring to isn't numbered but links #61 to the top of the radiator AND 58~60 in a 3 way split.

The goose that had my car before me decided it a good idea to place a large ball bearing inside the hose #61, thus blocking it off. Thus I had coolant boiling over from the radiator cap (return type). Does anyone know why anyone would do this?!?! ie. My return flow was directly from the top of the radiator to the return tank and NOT back and forth from the filler neck.

So I guess mine is normal after all (now that I've removed aforementioned ball bearing)... (Still trying to solve my overheating problem at high speed). So far I've got a new water pump, clean radiator and enough coolant. Timing is fine and my block is clean, mixtures are good and compression is not too high.

BUT I am running a thermofan and I do not have the air guide that's meant to sit underneath the rad. Could this be all I'm missing.

If ANYONE has a spare radiator shroud and air guide lying around and could send it to me for a reasonable price PLEASE let me know. Roadster parts down under are really rare...

Thanks for your help guys.

John,

I believe I have a fan shroud and an air scoop lying about some where. The scoop is a bit beat up but should be easy to straighten and it may be for a high windshield but it can easily be made to fit. On my stroker I run a Griffin aluminum custom radiator, no shroud or air scoop with an electric fan. I have no overheating issues. Are you sure you are not running a tad lean on the top end side? That will make her run hotter than normal. As to why the PO put a ball bearing in the hose going to the radiator fill neck is beyond me. We can work something reasonable out for the shroud and scoop if you are interested. Cheers.

Steve

Steve, yep I'm interested in the parts. My email address is johnfherron@gmail.com so drop me a line & we can take it from there.

Thanks so much for your help it's much appreciated!

John

ps. Sid - as you said the T-piece is a breather for the top of the rad then that ball bearing in the hose was blocking the air flow out of the pipe to the filler neck... so I probably have never been able to fill my cooling system up fully........? This may have been the problem all along... Here's hoping anyway no doubt I'll let you guys know the result next time I take her out for a strap! Cheers, John.

pps. Steve I'm still after the parts all the same!

Bungle,

That absolutely could have been the case! Best of luck getting it all squared away!

Thanks Sid.. I'm still not sure what I enjoy more... Working on the car or driving it... (Maybe I put that ball bearing in there while I was sleepwalking.... naaah....)