f7p/r and f4r strong points and weak points

[HAndy]

thought this would be a better place to ask the same questions ,rather than somebodys thread

what are the advantages /disadvantages over the the two basic f series engines
for a turbo application

are for instance the inlet manifolds on a f4 better flowed than that of the f7?
are the inlet /exhaust valves any bigger on the f4 over the f7?
are the bottom ends/oil pump systems stronger more effective on the f4
is the valve train stronger on the f4 or the f7
is the cam belt layout better designed/ more reliable on the f4r or f7
are the cranks stronger/weaker on the f4/f7
what are the differences in bottom /midrange/top end strength wise between the f7p/f7r and f4r
do they share the same weakness or strength ,is one better suited/more ideal as a base to start a turbo conversion from, with variable valve timing /uprated cams ,and compression ratios/ exhaust manifolds/costs put to one side, just the two raw engines so to speak

just like to clear a few things up as there seems to be little or no information on the above,?
i have'nt included the b18f as it shares the same basic block as the f7,but with a 8 valve volvo head ,but if it has strong merits (excluding costs per performance)please feel free















are the inlet valves any bigger on the f4
are the inlet exhaust / ports different in anyway for better or worse?
are the bottom ends stronger/ oil pump system stronger /better developed on the f4
is the valve train any stronger

[Os8472]

1. Different crank changes stroke to give 2.0 capacity
2. Pistons are dished
3. Strengthening ribs to rear of block
4. Chain driven oil pump directly from crank, therefore oil pump is different and sump baffle is 1 piece instead of 2
5. Front housing different (has a chain guide for the oil pump) Megane is flat on bottom unlike the rounded valver unit. Bolts to the sump differently
6. Auxilliary housing (oil pump drive) is deleted from the megane block and an idler gear is in its place
7. All the bolts which hold the sump, front housing, water pump & idler housing are E7 torx wheras the F7P are regular 11mm hex bolts. The front housing bolts are shorter on the megane, others are identical in thread size
(I would use the 11mm bolts as they are much easier to work with)
8. Dipstick and tube different. Also the brackets that hold the tube in place and brace the inlet manifold are different
9. Megane has 2 pin oil level sensor, clio has a 3 pin oil level sensor because this is also where it picks up oil temperature for the dash.
10. Bottom drive belt pulley on megane is bigger (im using the clio one)
11. Megane manifold and downpipe completely different in every way. The manifold fits but has an EGR valve on it, the downpipe needs modifying in a way i think is impossible but aparently it can be done.
12. Sump is different and has a proper rubber seal instead of sealer. 1 extra bolt in the megane sump
13. Megane cylinder head has bigger valves but small ports
14. Cylinder head also has a coil pack ignition system instead of dizzy cap and rotor arm. This means also that the entire engine wiring harness and ECU is different but id just use the valver or williams head for ease.
15. Megane has milder cams than F7P
16. Lower, inner timing cover different, due to the modified front housing
17. Oil pressure sensor is a different thread size on the megane, also in a different place making it impossible to access with any kind of tool
18. The bracket that braces the inlet manifold with the block is completely different on the valver, it has a clip which holds the oil breather and a clip which holds the oil level sensor which arnt there on the megane. The threaded bit on the valver block which holds this bracket is not there on the megane, making things awkward and the use of tie wraps may be required.
19. Megane engine is fitted with the oil cooler (oil/water heat exchanger) meaning the cooling hoses are different to match
20. The oil filter is therefore different, shallower. If you have ever changed an oil filter on a valver you will know why
21. Megane has the knock sensor in the top of the block rather than in the head like the F7P
22. Extra earth point for the megane loom at the bottom of the block

Copied from clio16valver.co.uk