Engine Size 1301 vs 1290

A

abarthcars

Low Mileage
Hi Guys,

Following my recent engine destruction and rapid hunting down a replacement. Last night talking to my wife, I thought have I dropped a clanger in buying the wrong replacement engine.

My original 1974 X1/9 I think had a 1290cc block, now the unit I have bought in a 1982 Fiat 128 is a 1301cc unit. I think it is only a small change on the piston diameter, but will the head and cam work with it. as I want to use these parts from the X1/9. Also will my gasket set fit?

Hope I haven't dropped a clanger here, any advice would be much appreciated.
 
well I know the Uno Turbo 1301 is based on the 1500, I have a gasket set for the Uno Turbo and will check what it says on the label.

EDIT: turns out my gasket set I have is for a Uno Turbo 1367cc, now I'm confused... hope you work it out :)
 
1290 is 86.0 bore size standard, 1301 is 86.4 bore size standard, head, etc etc interchange, BUT, the later model head will be a better choice as it has a better shape of combustion chamber.

See a thread I wrote over at turbo124 for a proper explaination.
http://www.turbo124.com/forum/viewtopic.php?f=10&t=5772

Cam from the 1290 should be 24/68, the cam from the 82 engine will be a 10/54 or similar.

Sump from the X19 will swap over, BUT make sure you use the oil pump pickup from the X19 engine as the sump base is at a different angle.

Intake manifold you will need to use the X19 style as again it allows the carb to sit level in the X19, 128's have the engine leaning futrher forwards, so the 128 inlet on an X19 will have the carb sitting not level.

SteveC
 
Hi Steve, so would I be right in thinking my best bet as the engine is running, is to keep the block and head together from the 1301cc engine, but use the cam and carrier from the 1974 engine. That way with the X1/9 cam and carb, the engine power output should be similar to the original X1/9 engine.

Giles
 
Correct...but swap the carby / inlet manifold, sump and oil pump pickup too... and then you have basically a late style euro X19 1300 engine... but slightly better as the cam in the early (pre 74) engines is better... so it should be a true 75hp potential (depending on milage / condition)

However, one thing the 128 engine won't have is the tapped hole for the oil pressure transducer (gauge sender) just above where the oil filter is... you will need to purchase a "doubler" to install the transducer and light sender into the hole just below the head level...Matt at Midwest X19 sells these doublers off the shelf, so it's a simple fix.

It would probably be a wise move to at least install a new timing belt too....

SteveC
 
Steve, I'm not going to pretend I understand everything you have written at turbo124, however, do you have any recommendations for us FI 1500 cars? Is the intake manifold and the runners worth porting?

FWIW I run a 1300 head with BV head and 35/75 cam.

Ed
 
RUNNING AGAIN

Firstly a huge thankyou to everyone who has helped advise me on this engine change in my 1974. What a job though. I was determined to get to the Autoitalia show this weekend no matter what, but to remove two engines, build a good new one from the parts and reinstall it in 9 evenings has taken its toll. My poor wife is again and X1/9 widow! And my eldest daughter has now stopped asking where daddy is at Bedtime, she's only three, but she now knows what an X1/9 is! ( that noisy green car )

Anyway I was supprised how many little changes there are between the two blocks.

One bit I am still stumped on is the fitting of a doubler for the oil pressure sensor, does anyone have a photo of one, so that I can source something in the UK.

Also how do you get over the dipstick tube problem. The original 1290cc block had a tapped hole with an extension tube. Where as the 128 1301cc block only has a plain hole. Obviously the 128 dipstick is now too short for the X1/9 Sump.:)
 
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