Renault F8M engine

In the early 80s, Renault began to develop a new power unit for its own R 9 car.

Description

In December 1982, a group of Renault engineers led by George Duane introduced a diesel engine, designated the F8M. It was a simple four-cylinder aspirated 1,6-liter, 55 hp. with a torque of 100 Nm, running on diesel fuel.

In the same year, the unit was put into production. The engine turned out to be so successful that it did not leave the assembly line until 1994.

Installed on Renault cars:

• R 9 (1983-1988);
• R 11 (1983-1988);
• R 5 (1985-1996);
• Express (1985-1994).

It was additionally installed on the Volvo 340 and 360, but in this case it had the designation D16.

The cylinder block is made of high-strength cast iron, not sleeved. Aluminum cylinder head, with one camshaft and 8 valves without hydraulic lifters.

Timing belt drive. Crankshaft, pistons and connecting rods are standard. Devices such as catalysts were missing.

Technical specifications

Manufacturer	Renault Group
Engine volume, cm³	1595
Power, hp from	55
Torque, Nm	100
Compression ratio	22.5
Cylinder block	cast iron
Cylinder head	aluminum
The order of the cylinders	1-3-4-2
Cylinder diameter, mm	78
The piston stroke, mm	83.5
Number of valves per cylinder	2
Timing drive	belt
Hydraulic compensators	no
Turbocharging	no
Fuel system	fore cameras
TNVD	mechanical Bosch VE
Fuel	DT (diesel fuel)
Environmental standards	Euro 0
Resource, outside. km	150
Location	transverse

What do the modifications F8M 700, 720, 730, 736, 760 mean

The technical characteristics of the ICE modifications do not differ from the base model. The essence of the changes was reduced to changes in the attachment of the motor to cars and connections to the transmission (manual transmission or automatic transmission).

In addition, in 1987 the cylinder head was somewhat modernized, but in general this only harmed the motor - cracks began to appear in the prechambers.

cylinder head F8M

Engine code	Power	Torque	Compression ratio	Years of issue	Installed
F8M 700	55 l. s at 4800 rpm	100	22.5	1983-1988	Renault R9 I, R 11 I
F8M 720	55 l. s at 4800 rpm	100	22.5	1984-1986	Renault R5 II, R 9, R 11, Rapid
F8M 730	55 l. s at 4800 rpm	100	22.5	1984-1986	Renault R5 II
F8M 736	55 l. s at 4800 rpm	100	22.5	1985-1994	Express I, Rapid
F8M 760	55 l. s at 4800 rpm	100	22.5	1986-1998	Express I, Extra I

Reliability, weaknesses, maintainability

Reliability

Despite some shortcomings, the internal combustion engine turned out to be quite reliable, economical and unpretentious in terms of fuel quality. It is distinguished by its simple design and ease of maintenance.

With proper operation, the motor easily nurses 500 thousand km without repair, which is more than three times the resource declared by the manufacturer.

The high-pressure fuel pump of the engine is distinguished by high reliability. As a rule, it does not fail.

Weak spots

They are found in every, even the most flawless motor. F8M is no exception.

The engine is afraid of overheating. In this case, a violation of the geometry of the cylinder head is inevitable.

Not a small danger is a broken timing belt. The meeting of the piston with the valves will also cause serious engine repairs.

Air leaks in the fuel system are not uncommon. Here, first of all, the fault falls on cracking pipes.

And, perhaps, the last weak point is the electrician. Often the wiring does not withstand the load, which leads to its failure.

Maintainability

The simple design of the unit allows you to repair it in any garage. Spare parts are also no problem.

The general rule to repair only with original parts also applies to this motor.

Given the high cost of original spare parts, it is worth considering the feasibility of repair. Sometimes it is easier to purchase a contract engine for 10-30 thousand rubles than to repair an old one.

The F8M engine was the first in the history of Renault diesel engines installed in passenger cars.