jjacob
Member
Well I have been putting together a plan to improve my 1969 500L. I am in the USA. I have been reviewing information on this as well as other forums. I am looking for some feedback on my plan from the forum.
I have talked to an acquaintance of mine who is one of the three big suppliers of 500 bits and pieces in the USA. He has used 126 engines and transmissions here in the USA in his warehouses.
First let me describe the intended use of this car. It currently has a stock 499cc engine and transmission that runs very nice and smooth. I would like to get more horsepower and torque to make the car more enjoyable to drive up hills, in traffic, and be able to maintain 65 mph (105 kph). I need syncromesh in the transmission in order for my wife to be able to drive it. I am not looking for a screamer, we will be staying to under 5000 rpm. Torque is more important than ultimate horsepower. I am not looking to spend huge amounts of money. I am capable of doing all of the work (except machining) myself.
My acquaintance with the Fiat spares business does not think I need to use a 126 engine as a base, even though he has engines to sell me. He says to just use my current engine (110F) as the basis for the upgrade, and buy a used 126 transmission from him. He says to swap over the bellhousing and axles, and bore the block and clearance the cylinders for the crankshaft.
Here is the plan: Using my current 110F engine as the base.
Cylinders/Pistons - 79.5mm
Camshaft - mild, 30/70?
Cylinder head - mild port and polish, 34mm intake valve, stock exhaust.
Carburetor - unknown at this time but must be reasonable in cost. Still researching this, lots to chose from.
Ignition: Already upgraded to Pertronix ignition system.
Lots of engine bits and pieces will be replaced in the normal course of a rebuild.
On the Nanni Ricambi site they show separate kits for F/L cars (110F) vs. R/126 (126a)
QUESTION 1: For the F/L 700cc kit they show a steel cylinder support that they do not show for the 650cc kit or the R/126 700cc kit. Is 79.5mm too much for the 110F block? Or am I OK if I use the steel support. Should I limit the bore increase to 650cc?
QUESTION 2: For the F/L 700cc kit they show replacement connecting rods that they do not show for the F/L 650cc kit. Are these necessary for the 700cc overbore or can I use the stock rods?
QUESTION 3: Why are there separate kits for the F/L cars (110F) vs. R/126 (126a)?
Lastly, I would like to end up with a compression ratio of around 8.5 - 9.0/1. With either a 650cc or 700cc engine what is the best method. I am assuming my head to be stock.
Thanking everyone in advance for your input.
John
I have talked to an acquaintance of mine who is one of the three big suppliers of 500 bits and pieces in the USA. He has used 126 engines and transmissions here in the USA in his warehouses.
First let me describe the intended use of this car. It currently has a stock 499cc engine and transmission that runs very nice and smooth. I would like to get more horsepower and torque to make the car more enjoyable to drive up hills, in traffic, and be able to maintain 65 mph (105 kph). I need syncromesh in the transmission in order for my wife to be able to drive it. I am not looking for a screamer, we will be staying to under 5000 rpm. Torque is more important than ultimate horsepower. I am not looking to spend huge amounts of money. I am capable of doing all of the work (except machining) myself.
My acquaintance with the Fiat spares business does not think I need to use a 126 engine as a base, even though he has engines to sell me. He says to just use my current engine (110F) as the basis for the upgrade, and buy a used 126 transmission from him. He says to swap over the bellhousing and axles, and bore the block and clearance the cylinders for the crankshaft.
Here is the plan: Using my current 110F engine as the base.
Cylinders/Pistons - 79.5mm
Camshaft - mild, 30/70?
Cylinder head - mild port and polish, 34mm intake valve, stock exhaust.
Carburetor - unknown at this time but must be reasonable in cost. Still researching this, lots to chose from.
Ignition: Already upgraded to Pertronix ignition system.
Lots of engine bits and pieces will be replaced in the normal course of a rebuild.
On the Nanni Ricambi site they show separate kits for F/L cars (110F) vs. R/126 (126a)
QUESTION 1: For the F/L 700cc kit they show a steel cylinder support that they do not show for the 650cc kit or the R/126 700cc kit. Is 79.5mm too much for the 110F block? Or am I OK if I use the steel support. Should I limit the bore increase to 650cc?
QUESTION 2: For the F/L 700cc kit they show replacement connecting rods that they do not show for the F/L 650cc kit. Are these necessary for the 700cc overbore or can I use the stock rods?
QUESTION 3: Why are there separate kits for the F/L cars (110F) vs. R/126 (126a)?
Lastly, I would like to end up with a compression ratio of around 8.5 - 9.0/1. With either a 650cc or 700cc engine what is the best method. I am assuming my head to be stock.
Thanking everyone in advance for your input.
John
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