Cooling in early car with C3 motor (quite long)

[Gilbert '71 T]

Hi all,

I have a question hope you guys can help regarding the plumbing of a front mounted cooler into a ‘71 car, with a 3.0 motor using ‘71 lines. Confused? I am

Bit of background…the car is a ‘71T with a Carrera 3.0 engine which had a nasty oil pump seizure incident recently, but that‘s all behind me now and the engine is 40% rebuilt with new bearings/pump/shaft/drive gear/chains/sprockets (top end was also done 200 miles before the pump incident), it should be finished early next week.

I used the 71 on-engine cooler and all of ‘71 tank/lines for simplicity but temps were a bit high so would like some extra cooling on refitting the 3.0. As I understand the C3 in stock form had a trombone up front, which I have, but will probably upgrade to a 28 row brass cooler if there‘s not enough cooling from the ‘bone‘, also have some offers on the rest of the lines back to the engine/stat & tank but they are quite pricey so it‘s looking like I may have to bite the bullet and pay out. But my big question is will the lines 9/10 in the diagram below mate up to the ‘71 tank/scavenge lines/on engine cooler?



I first thought the front cooler worked on the scavenge side (I.e if too hot once out of the engine the send it through the cooler) but looking at the above diagram it looks like the oil takes the following route/s

From tank to stat
If cool enough then to supply tube through to on engine cooler
Through pump/engine
Out scavenge and back to tank

Then once above stat opening temp….

From tank to stat
Through front cooler and back to stat
Then to supply tube through on engine cooler
Through pump/engine
Out scavenge and back to tank

Is the above correct or am I way off here? If not does this mean I just need an adapter from stat to tank & stat to supply tube through on the engine cooler if of course lines 9/10 won‘t fit?

Help I’m confused because i also saw this on Elephant Racing's site..

[Jubbie]

The way I understand the flow is this way...

From the engine sump into the scavange pump
From out of the scavange pump to the t-stat

If cold - From t-stat to tank and from tank back to pressure pump in engine

If hot - From t-stat to front cooler then back to tank and then back to pressure pump in engine.


When I put my C3 into my 74,

I also put the SSi Hx I had from my 74 engine. I took the hard line which goes from the scavange pump (fitting on the drivers side of the engine case under cyl #3) to the external t-stat and retrofited without modification to the C3 engine. The rubber hose from the bottom of the oil tank to the inlet of the main pump (in the engine which the connector is on the engine heat exchanger) and it was a direct fit. The 71' engine may have different connection points, but I dobut it.

It should be a complete no mod retrofit.

Now the fuel lines and the engine wiring is a different story.

[Gilbert '71 T]

Thanks for the clarification John,

As I first thought, I was getting way too confused there, I remember now that i couldnt use the 74 type scavenge line because I'm using the 71 heat exch and 71 transmission and clutch set up. The 74 scavenge line fouled the clutch as it runs under the trans, so I think what I need are the following then:

lines to front cooler
t-stat
Both lines 9 & 10 in the diagram above
1 male/male adapter to mate line '9' to my '71 type scavenge line 26mm>30mm
another male/female adapter to mate line 10 to my '71 tank 26mm>30mm

from the elephant racing info it appears that later lines used 30mm connections as opposed to 26mm connections on earlier cars, hence the adapters

btw thankfully fuel lines and wiring are already sorted