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sk8xtrm
27-01-2015, 16:44
I have a question really on the differences between the different block numbers, when I was changing my clutch in my new clio I noticed my block was stamped with "f7r a 700" which I assume is the williams lump but I have also seen people references the numbers 710 and 714 which i think are megane f7r lumps

I just wanted to ask out of curiosity more, is their any difference in these engines internally? is one more desirable? etc

Thank you :)

Vandella
27-01-2015, 17:30
the 700 ur right is the Williams lump, the 710 I believe were the meg f7r's and then the 714 is the spider's f7r.. hopefully someone will correct me if i'm wrong..

Main differences being the heads on each..

710 and I presume the 714 have slightly bigger valves and the ignition sequence is done differently.. as the Williams uses a dizzy cap..

16v_paddy
27-01-2015, 23:51
710 & 714 are both megane blocks, the 714 is just the later versions of the car. The spider is 712.

The 710 block is virtually identical to the 700 with the same crank as the diesel :lol: All the others have a different crank as the oil pump is chain driven straight off the crank itself, they're very very similar in their construction & how they work to the F4R which was basically a development of the later 712 & 714 F7R's.

The megane heads are all the same though, same small ports, 33mm inlet valves & 29mm exhaust valves. They make slightly better power & torque than the williams lump and that's with a milder cam profile. Fitting williams cams to a megane head will give you a significant improvement as well as they're more aggressive

sk8xtrm
29-01-2015, 21:00
Thank you for clarification guys, I was asking out of curiosity more than anything and I didn't actually know. not a vast difference in block then rather just the head i.e valves, coil/dizzy etc

PhilW
30-01-2015, 11:17
710 & 714 are both megane blocks, the 714 is just the later versions of the car. The spider is 712.

The 710 block is virtually identical to the 700 with the same crank as the diesel :lol: All the others have a different crank as the oil pump is chain driven straight off the crank itself, they're very very similar in their construction & how they work to the F4R which was basically a development of the later 712 & 714 F7R's.

The megane heads are all the same though, same small ports, 33mm inlet valves & 29mm exhaust valves. They make slightly better power & torque than the williams lump and that's with a milder cam profile. Fitting williams cams to a megane head will give you a significant improvement as well as they're more aggressive

Thats really interesting regarding the Megane heads Paddy :grin:
Are all 2.0 Megane heads the same? Regardless of the model? And fitting one of these with Williams Cams will give significant improvement over std? Wouldnt have expected that! Is this something that you have tried yourself or know about?
When I hear about things like this, I always wonder why Renault didnt go down this route in the first place.
How does the above (using a Megane head) compare with big valve conversions, porting etc? :thinking:

sk8xtrm
30-01-2015, 15:12
Thats really interesting regarding the Megane heads Paddy :grin:
Are all 2.0 Megane heads the same? Regardless of the model? And fitting one of these with Williams Cams will give significant improvement over std? Wouldnt have expected that! Is this something that you have tried yourself or know about?
When I hear about things like this, I always wonder why Renault didnt go down this route in the first place.
How does the above (using a Megane head) compare with big valve conversions, porting etc? :thinking:



Wouldn't a megane head need to be machined anyway to fit the dizzy?

16v_paddy
30-01-2015, 23:10
Thats really interesting regarding the Megane heads Paddy :grin:
Are all 2.0 Megane heads the same? Regardless of the model? And fitting one of these with Williams Cams will give significant improvement over std? Wouldnt have expected that! Is this something that you have tried yourself or know about?
When I hear about things like this, I always wonder why Renault didnt go down this route in the first place.
How does the above (using a Megane head) compare with big valve conversions, porting etc? :thinking:

Mk1 megane F7R yes, heads are all the same. Exploding_penguin on here, his car made 165bhp, rebuilt megane f7r with williams cams, others have made around the 160bhp mark with the willy cams.

The key to the megane head being better than big valve williams heads is all down to the port sizes. They're smaller but the effect that has is speeding up the gases entering the engine which makes it much more efficient.

The reason Renault made them with milder cam profiles is to keep the new engines in line with bullshit emissions regulations so they're allowed to sell them :whip: As for how a non ported megane head compares to a ported & bigger valved williams head, what I can say is that my bottom end when mated with a big valve & properly flowed willy head (before I bought it) made 222bhp & 170ft/lb - I fitted a flowed megane head & milder cams & made 240bhp & 181ft/lb. But for a better comparison, snowman's car KUX, his was a very similar spec to mine (same cams - catcams 213's) but with a ported williams head & making 211bhp - can't remember the torque off the top of my head though


Wouldn't a megane head need to be machined anyway to fit the dizzy?

Depends what you're doing tbh, if you intend to stick with the standard ecu then yes there's no other way around it. But if you're going for full megane ecu & loom (total ballache & not recommended if you wish to keep your sanity) or standalone, you can leave it as it is