1300/1500 crankshaft
- Thread starter CnC79X19
- Start date
Brad Garska
True Classic
CnC79X19
True Classic
Thanks Brad
tjbabar
Low Mileage
The crankshafts are different, different stoke, but are they interchangeable? Can I put a crankshaft from a 1500 motor in my 1300 to increase the displacement? The bores are very close.
1300 motor: 128.AS.000 - 86 bore - 55.5 stroke - 1290cc
1500 motor: 138.A2.000 - 86.4 bore - 63.9 stroke - 1498cc
1300 motor: 128.AS.000 - 86 bore - 55.5 stroke - 1290cc
1500 motor: 138.A2.000 - 86.4 bore - 63.9 stroke - 1498cc
The problem is that 1500 block is taller than the 1300 block to accommodate the longer stroke. Put a 1500 crank into a 1300 block and at top of stroke the piston will hit the top of the combustion chamber.
MikeHynes
True Classic
Yes, they are interchangeable. No they are not the same. The 1500 crank has a longer stroke.
You can't use the stock pistons and rods if you mix cranks though.
PBS cast a crank that they used to increase displacement to 1600cc using stock 1300 rods and custom pistons (with the pin height moved up) in 1300 blocks. The same crank could be installed in the 1500 block with stock 1500 rods and modified (top had to be milled down) stock 1500 pistons.
You can't use the stock pistons and rods if you mix cranks though.
PBS cast a crank that they used to increase displacement to 1600cc using stock 1300 rods and custom pistons (with the pin height moved up) in 1300 blocks. The same crank could be installed in the 1500 block with stock 1500 rods and modified (top had to be milled down) stock 1500 pistons.
If you have not read Steve Cecchele's ultimate SOHC I encourage you to read it. It has a lot of information.
https://xwebforums.com/forum/index.php?threads/ultimate-sohc-engine.22546/
https://xwebforums.com/forum/index.php?threads/ultimate-sohc-engine.22546/
Rupunzell
Bernice Loui
Beyond the piston, con rods block being different between the 1300 -vs- 1500cc engine, the stroke to con rod ratio is different due to the different length con rods between the 1300 -vs- 1500cc engine. Stroke to con rod ratio is one of the designed in magical items that makes this Lampredi engine so very special. There is a common belief-idea bigger is always better, it is no where near this simple.
IMO, if a 1500 is wanted, get a 1500cc engine and go from there.
Bernice
IMO, if a 1500 is wanted, get a 1500cc engine and go from there.
Bernice
Dr.Jeff
True Classic
Clif, I'm not sure if the intended outcome was to make the 1300 into a 1500. But if it was, honestly it isn't worth the cost/work required to get there. As has been stated, it would be better, easier, and much less expensive to just get a 1500 engine.
However you might have other ideas in mind? In that case tell us more and maybe there is something to add.
However you might have other ideas in mind? In that case tell us more and maybe there is something to add.
tjbabar
Low Mileage
The intent is to avoid the EGR on the 1500. I live in California and a smog test is required every 2 years. The EGR on the 1500 is more complicated than the 1300. The EGR on the 1500 comes out of the exhaust manifold, through a temperature controlled valve, into the intake manifold. The EGR on the 1300 comes out of the back of the head to the air-pump then into the air filter. Much simpler. I want the increased displacement and horsepower of the 1500 without the complicated EGR. Any ideas?
carl
True Classic
The 1500 is so much torquier than the 1300 that the swap is worth it even if you can't come up with a pretty solution for the EGR.
You can also consider the labor intensive method. Years ago, I had to get my 78 spider inspected every two years. I was running the motor detoxed and with dual Webers. Every two years I removed the dual carbs, installed my manifold/single carb, installed the air pump and plumbing, turned the ignition timing back from 10 to zero degrees and reinstalled the cat (it was a California car)...staggered and chugged to the inspection station, passed emissions and spent the next day detoxing and reinstalling the dual Webers.
You can also consider the labor intensive method. Years ago, I had to get my 78 spider inspected every two years. I was running the motor detoxed and with dual Webers. Every two years I removed the dual carbs, installed my manifold/single carb, installed the air pump and plumbing, turned the ignition timing back from 10 to zero degrees and reinstalled the cat (it was a California car)...staggered and chugged to the inspection station, passed emissions and spent the next day detoxing and reinstalling the dual Webers.
Rupunzell
Bernice Loui
Check with CARB on engine updates, then:
Install a later EFI 1500cc, CA-CARB legal version complete in to the exxe. Make absolute sure all the oily bits are GOOD as these engines are decades old, most are completely wore out (engine and Bosch EFI) and will need stuff before serviceable.
Then take the exxe to a CARB referee station, explain precisely what was done. If all goes well, CARB will issue a special SMOG sticker noting this has a CA legal later versions engine and it will be SMOG checked as the year of that engine.
Bernice
Install a later EFI 1500cc, CA-CARB legal version complete in to the exxe. Make absolute sure all the oily bits are GOOD as these engines are decades old, most are completely wore out (engine and Bosch EFI) and will need stuff before serviceable.
Then take the exxe to a CARB referee station, explain precisely what was done. If all goes well, CARB will issue a special SMOG sticker noting this has a CA legal later versions engine and it will be SMOG checked as the year of that engine.
Bernice