Uno Turbo engine in X1/9

Dr.Jeff

True Classic
I know there are a few members with UT engines in their X, and many more that have UT knowledge, so here are a couple questions:

1) For the coolant lines to/from the turbo, in the Haynes manual (only workshop reference I have for it) there is a picture of the system. Although it is not labeled, and I found no reference to it in the description, there appears to be something in the coolant return line, about half way between the turbo and recovery tank. Is there a check valve or something in that line on the stock design?

2) Despite having inter-changeable components, I've read that the UT uses different gaskets than the FI X1/9. The ones I've seen mentioned are for things like the manifolds to the head, between the intake runners and the plenum, etc.. But possibly also for other gaskets on the engine. Likewise for any seals; fuel injector seals, front/rear main seals, shaft seals, or any other places where such items are distinct to the UT application. Please verify these differences and provide some part numbers (or at least detailed descriptions) for the gaskets/seals that are different.

Thank you for the info.
 
1) From memory, the item you see is an orifice tube for the crank case breather system. It is a cast alloy item and looks like two short pipes crossing at 90 degrees. One pipe has the orifice, about 1/8", which controls the rate of blow-by gas sucked into the turbo inlet. The other pipe is straight through and just connects the two halves of the coolant return hose from turbo to header tank. It is important the turbo coolant circuit is replicated when placed in the X1/9, as it stops your turbo cooking itself. You need to use an UT header tank or early steel X1/9 tank as the return hose has to be a minimum 7/16" ID.

The crank case breather has to go in between afm and turbo as a the afm would get contaminated otherwise. Thus the breather gas is not measured directly by the afm for mixture control and so has to be controlled by the orifice so the ecu can compensate for it.

2) The intake/exhaust manifold gasket Fiat part numbers are 5891220, 5999355, 7625272 or 7625273. They have oval shaped nitrile rubber trimmed inlet holes. Some versions have metal trimmed holes. I'm not sure about the plenum-inlet runner gaskets. I don't believe any of the other engine seals are different. The big end bearing shells have extra holes for the piston oil squirter holes in the con rods. This makes a set of 1.3 turbo bearing shells about twice the price of regular sohc shells, just for the holes. The "Tipo" 1.4/1.6 engines used squirter jets fitted in the crank case, so the big end shells reverted to the cheaper original sohc items.
 
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Thanks Rachael, appreciate you sharing your vast knowledge about the UT.

1) Regarding the turbo coolant return line: The Haynes manual I have is a PDF copy and I don't have the ability to post the image here. But it is in the 1996 edition, page 13-56, figure 13-30. The title states this illustration is for the Mk2 UT, and I'm working with components from a Mk1 UT, so this might have changed. But the item in question does look to be something of a "T" shape, however there are no other hoses shown attaching to it (other the the coolant return line). That might just be how they illustrated it though (it's not a photo of the real thong, just a sketch). The system you describe (blow-by flow controlled by coolant line) sounds rather odd to me, but hey...its a Fiat so everything sounds odd to me.

2) Regarding the UT gaskets/seals: Thanks for the part numbers. Indeed, the manifold gaskets appear different with seals around the ports so I wanted to find the correct ones (however as you say, some listings seem to show gaskets without those port seals). As for the gaskets between the plenum and runners, I saw a comment in a old post saying they are different for the UT, but I have no idea if this is true. The 1500 and UT intake manifolds appear to be the same size/shape but I don't have the old UT gaskets to compare with.

Here is my dilemma; I wish to replace all of the external (and some internal) seals and gaskets on a 1500 engine with the UT turbo system installed. I am considering buying a complete engine seal/gasket kit rather than all of the individual pieces. Would it better to get a kit for the 1500 plus the UT specific gaskets (e.g. manifolds), a kit for the Mk1 UT (I don't plan to use either head gasket, going to MLS), or buy the pieces individually and mix/match as necessary?

Regarding the oil squirters on the Tipo engines: I assume that engine has oil ports cast into the block to feed those jets? I'm sure this is not a simple conversion onto the 1500 block.

Thanks again.
 
Always welcome Jeff! I should clarify - in the X shaped casting, the two pipes are not connected in any way. I believe this is just due to packaging. The two pipe routes happen to cross at that location in the engine bay. One end of the orifice pipe is actually plugged into the large afm-turbo swan neck pipe. I guess it was convenient to join the two pipe routes like this to both give support and to prevent them chafing.

I would use a 1500 top set of gaskets (with 10 bolt or 14 bolt head gasket depending on your engine age) and substitute in the UT gaskets where needed. For the intake runners, it would probably suffice to use a good gasket compound to ensure a good pressure seal.

The Tipo engines have simple drillings in the main bearing saddles, one for each cylinder. They are angled to squirt into the backs of the pistons. The holes are bored with two diameters with a step or shoulder near the top where the bore reduces. A jet nozzle with an internal ball and spring valve is press fitted in each hole, sitting against the shoulder in the bore. The ball valve only opens when oil pressure is up to a certain pressure, to ensure an adequate jet to hit the piston as well as preserve the oil feed to the bearings on start up. The nozzle is fed oil from the oil feed groove in back of the bearing shell. All of this can be replicated in the X1/9 block by a machine shop. I think Guy Croft does a similar thing for twin cam engines. This is a similar squirter in a Cummins engine (with thanks to the Dodge Cummins Forum).
Cummins oil squirter.jpg
 
Thanks Rachael,

the two pipes are not connected in any way
Got it. So maybe the bit shown in the Haynes illustration is just a 'clip' of some type to hold the two lines in relative position, as they "X" one another.

I would use a 1500 top set of gaskets
I should have clarified, I'm thinking of getting a complete engine gasket/seal kit (vs head set). That way I get the shafts' lip seals, pan gasket, etc. along with the items for the upper half. Often it is more economical to get the complete set even if not doing a proper rebuild (I'm doing more of a engine re-seal) and don't need everything. Plus this way you have the extra bits on hand should you want them later. It's too easy to forget the small stuff when ordering individual gaskets/seals. But I think your answer would be the same...get it for the 1500 and pick up any unique UT items (e.g. manifold gaskets) separately.

Cleaver simple design for the oil squirters. I'll have to check around for a machinist that I feel can do the mod competently (that last criteria is not so easy to find any more). I assume only those "yellow" pieces are what's needed to make the mod (once the saddles are machined). Do you happen to know if the squirt jets are available (part number would be very helpful)?

Thank you, Jeff
 
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