Have you ever wanted a 16V head on your X engine?

Interesting read. Was just wondering what it would take to do a 16V conversion (keeping stock bottom end) clearly not a practical consideration ;)
 
As stated the block to head relationship is not a happy one between the 16v and our 138 series block.

There was one of these engines sold here in Michigan about a decade and a half ago which was bought by a man named McBride (as I recall) who put it into an red white and blue painted X as I recall.

He sort of disappeared/aged out or ? and the car I believe was sold. Somewhere I have some info about the change over. There is a fair amount of info on the Australian 124T site about several of these conversions. I will look for the pics and related info I have about them and post it up.

The standard cams and arrangement give an engine with good torque to 5k and they run out of breathe around 6k, so not the high winder we are used to.

This has always interested me as a solution to getting to a higher hp car, particularly if a 1.9 could be created with some hotter cams and higher compresssion. Then it would be all FIAT and hopefully able to offer a normally aspirated 160hp which doesn't seem unreasonable.

I look on eBay periodically in the EU for them as I dream...
 
"The standard oil pump in a 1581 16v was from the 1581 Tipo 8v - and it isn't upto the job of feeding the same engine PLUS 4 piston squirters and 16 leaky lifters. This is why most of the 1581 16v road cars you hear sound rattly. We basically had no choice but to fabricate a new oil pump."

Is there any reason not to use an external oil pump? Rules?
 
Interesting that this thread has been resurrected! I recently decided to have a go at a 16V install and recently bought a crash damaged Stilo to ensure I had all the bits I might need. I see there are quite a few of these engines popping up on eBay these days.

Further musings:

I don't see a great problem with deleting the second idler pulley, it would I think result in a similar situation to the big brother 16V engine. The second idler as you can see in my earlier pic is perhaps more to provide room for ancillaries to fit snug the front side of the block - I think the a/c compressor fits to that large ally bracket on the right.

For the Punto GT engine, an auxiliary pulley is used that is smaller than the regular 2x of crank pulley diameter, making the auxiliary shaft turn at something like 5/8 crank speed rather than the original 1/2 crank speed. The dizzy drive gear is amended to return the correct 1/2 crank speed for the dizzy (actually a phase sensor on the PGT). This has caught out a couple of Uno Turbo modders when swapping their UT toothed pulley sets for PGT ones - their dizzy drive went up the creek! The upshot of this is that if you didn't need the phase sensor (only needed for full sequential fuel injection and ignition), you could use an original X1/9 auxiliary shaft and dizzy/oil pump gear with the Punto toothed pulleys etc., giving you a boost in oil pump speed. I wonder if this would help the marginal oil pump capacity Franken has mentioned?
 
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you could use an original X1/9 auxiliary shaft and dizzy/oil pump gear with the Punto toothed pulleys etc., giving you a boost in oil pump speed.

Hi Rachael,
I had been trying to research this and hadn't found anything yet.
Can you explain how one would boost the oil pump speed?
Would you be using an X1/9 oil pump or the PGT pump (are they the same?)
Thanks.
 
Punto GT auxiliary shaft and oil pump drive gear are a different numerical ratio, so don't spin at half crank speed, but slightly slower...1600 and 1300 auxiliary shafts are notthe same; well the shafts are close enough (same number of teeth and pitch but different diameter), but the oil pump/distributor drive gear has one extra tooth (thus Punto oil pump runs slower, and it's got no dizzy). The main effect is that if you are running a block mounted distributor, you only get a well timed spark every 6 revolutions, which is just enough to get you interested but not enough to get it running.

AFAIK the punto aux shaft belt driven gears are the same size and tooth count, but with a different tooth profile

punto and 1300 shafts and gears.JPG


so in theory you could boost the oil delivery on your punto block by using the stock 1300/1500 aux shaft and gear to speed the drive up, but the other way around would actually slow things down...
 
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So if I dropped a Punto GT oil pump into my X1/9, everything else staying stock, I would have more oil pressure?
 
AFAIK punto GT / uno turbo and all later sohc use the same ten tooth oil pump, which will fit an X19 engine after the pickup is changed (to suit the engine tilt / alloy sump), the additional tooth would mean increased oil flow, Fiat part number for the ones I have used is 5962426. Stock X19/128 and lots of other sohc is 9 tooth. 5962426 also has the longer spline length at the drive gear end.

Increased flow doesn't necessarily equate to increased pressure...the biggest factor that determines pressure is still bearing clearances, and excessive clearance at bearings / bushes like the aux shaft bearings and the oil pump drive gear bush (which are actually the 'first port of call' after the oil pump before the main bearings) will mean less pressure and oil delivery to the mains/big ends.

I've even run into excessively worn cam journals in the cam housing that caused low oil pressure, as this was bleeding off pressure from other components... remember it's a closed system and pressure (if there was no leakage) would be equal throughout the entire system, and just like water (or electrons) it will find the easiest path, so if there was a large clearance at one journal most of the oil delivery delivery would flow out from this point

SteveC
 
Looking at the Haynes manual, it's obvious to me now that the X1/9 aux pulley is not the same size as the cam pulleys, I was thinking of the TC engine perhaps, so my earlier numbers are not quite right but the principle is the same; the Punto aux shaft turns somewhat faster than the X1/9 shaft for any given crank speed. Thus they must have different drive gear ratios, as they must both bring the pump/dizzy shaft speed back to 1/2 crank speed. You can only use your chosen aux shaft with its matching driven gear, you can't mix and match as they will not mesh.

So, for X1/9 engines, it sounds like there may be an advantage to be had by using a Punto oil pump if its shaft splines match the X1/9 driven gear, and/or you could swap the X1/9 toothed pulley set for a Punto set and go distributorless, as you will have lost the 1/2 crank speed dizzy.

For a Stilo engine the only way to up the pump output is to speed it up using the X1/9 aux shaft and gear swap, or get a bespoke deeper pump made, or get a custom small aux pulley. I don't have any dizzy to worry about.

Tomorrow I will go and do a pulley survey to get my head round all of this!
 
Thanks Steve, that helps a lot.
However, when i google the part number you stated, I keep getting references to this being a Fiat 128 oil pump.
Are you sure that is the part number for the 10-tooth pump?
 
Thanks Steve, that helps a lot.
However, when i google the part number you stated, I keep getting references to this being a Fiat 128 oil pump.
Are you sure that is the part number for the 10-tooth pump?

Steve's right, I bought one and can confirm it's a 10 tooth pump. You just have to switch the pick up from your X1/9 pump.

Cheers,

Rob
 
Thanks Steve, that helps a lot.
However, when i google the part number you stated, I keep getting references to this being a Fiat 128 oil pump.
Are you sure that is the part number for the 10-tooth pump?

That's because the pump will fit a 128, and still uses the 128 casting for the pump body... the gears are the same LENGTH, so fit into the regular 128 casting pump body, it's simply they are cut with an extra tooth on each gear ... the only external visual sign I know of is the extended spline on the drive shaft. 5962426 fits lots of later model vehicles delta/regata/uno/punto some of which have a 1.6 8 valve variant. The change to the ten tooth gears seems to be 1986 onwards.

5962426 pump.jpg 5962426a.jpg

The 1.6 16 valve uses a different pump, but I've never had one to look at and compare to a regular 8 valve pump... but looking at photographs it uses a different method of oil pressure relief valve, which is why i've never bought one to compare...

delta 16 valve oil pump 1996 on.jpg

SteveC
 
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Thanks.
Unfortunately, I am still somewhat confused. In my research, I found a thread in a german Uno Turbo forum, which claims that the Turbo pump is this one, which only has 8 teeth:
665.jpg


The non-turbo version is shown as the 10-tooth pump:
664.jpg


The post also claims that fewer teeth means more flow volume.
I need to verify that.
I guess the flow volume would correspond to the void area of the rotor, but it is hard to gauge that from just looking at the pictures.
(draw circle around the gear, determine total area of air in that circle, the gear that has more air within the circle has higher flow rate).

Also, this thread, which is from 2010, claims that the turbo pump is no longer available!
 
It depends on the volume that's 'trapped' between the gears and the pump housing... positive displacement pumps work by pushing the oil around between the gear and the housing... and the ten tooth pump has 9 pockets of oil while it's rotating, the 8 tooth pump has 7 pockets of oil while it's rotating... if the volumes of the 'trapped' oil is equal then the higher tooth count will a better delivery rate as it has a better sealing ability between the gear and the housing (given the same clearances) as it has more sealing points (11 vs 9) around the gears circumference.

I've never had an 8 tooth pump to measure and check...you've piqued my interest here and now I've got to find an 8 tooth pump to measure!

SteveC
 
For a Stilo engine the only way to up the pump output is to speed it up using the X1/9 aux shaft and gear swap, or get a bespoke deeper pump made, or get a custom small aux pulley. I don't have any dizzy to worry about.

Tomorrow I will go and do a pulley survey to get my head round all of this!

I keep forgetting to ask you - what motor is in your Dallara Blog? - the red intake manifold one....
 
I saw the post in T124 quoted by Steve above. This is not quite right - the Punto GT has a "phase sensor" instead of a dizzy and this *has* to run at 1/2 crank speed, which means the PGT oil pump runs at 1/2 crank speed, same as any 128/138 block mounted dizzy engine.

Anyway, after some tooth counting and looking at interweb photos I have concluded so:

Engines with the 10 mm pitch square toothed pulleys (128/138/Mk1 UT) must have a 21 tooth crank pulley and 30 tooth auxiliary pulley. The auxiliary shaft gear has 10 teeth, pump dizzy gear has 14 teeth (as per Steve's photo above). Thus the aux shaft runs at 21/30 = 0.714 x crank speed , then the pump/dizzy runs at 0.714 x 10/14 = 0.5 crank speed.

Later sohc engines (PGT/Mk2 UT) have an 8 mm pitch round tooth cam belt. This engine has a 24 tooth crank pulley and a 32 tooth aux pulley. Thus the aux shaft runs at 24/32 = 0.75 x crank speed, its skew gear has 10 teeth and the pump/dizzy driven gear has 15 teeth (again as per Steve's photo above), thus the pump runs at 24/32 x 10/15 = 0.5 x crank speed.

The Stilo engine I have has a 24 tooth crank pulley and a 28 tooth aux pulley. Thus the aux shaft runs at 24/28 = 0.86 x crank speed. I have no idea of the gear ratio for the pump drive though.

What this means is that if you are prepared to lose your block mount dizzy you can up your 128/138 engine's oil pump speed by swapping from a square tooth pulley set to a newer 8 mm pitch round tooth pulley set from the later engines, but keeping your original aux shaft in place.

Those with a PGT/Mk2 UT engine can use an earlier type aux shaft and driven gear and/or use a Stilo 28 tooth aux pulley. Both methods will preclude a block mounted dizzy/phase sensor. Using a 28 tooth aux pulley will probably require a non-stock cam belt.

Hopefully with my Stilo engine I can use an earlier type aux shaft and driven gear.
 
Hi Hussein, that is the Alfa GTA V6 engine in my "20k Junker" X1/9. Progressing at a glacial pace. Last photo below, last I heard he was starting on the left side wings.
2012-04-27 18.00.07.jpg
 
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There was one of these engines sold here in Michigan about a decade and a half ago which was bought by a man named McBride (as I recall) who put it into an red white and blue painted X as I recall. He sort of disappeared/aged out or ? and the car I believe was sold. .[/QUOTE said:
Russ McBride. There was a website dedicated to the car/conversion about ten years back. The car was sold on eBay I believe. It's new owner was in US at the time. I lost track of it at this point.
 
HI, guys. I didn't die or anything. Just moved on to other car types. I'm still living in the Atlanta area.

I'm not sure what happened to my old Red/White/Blue 16v X1/9. Some guy came (from out west, I think), bought the car and after he drove away I never heard from him again.

I miss the car (and my other X1/9's - I think I had about a dozen). Great cars. Nothing else like 'em.

Glad to see Xweb is still going strong.
 
Glad to see you are still with us.

Do your still have details about how you put that particular car together? I remember parts of your build but it was before I got used to information disappearing from the net and started saving the interesting bits...

All the best and thank you.

HI, guys. I didn't die or anything. Just moved on to other car types. I'm still living in the Atlanta area.

I'm not sure what happened to my old Red/White/Blue 16v X1/9. Some guy came (from out west, I think), bought the car and after he drove away I never heard from him again.

I miss the car (and my other X1/9's - I think I had about a dozen). Great cars. Nothing else like 'em.

Glad to see Xweb is still going strong.
 
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