f7r block differences

[2 live]

rite ..........heres one for the real techies hehe

wots the difrences exactly between the willy n megane 2.0s??

k-tec dont know

evryone iv tried to find out of (bar 2 ppl) havent really got the expertise in the engine to identify even the basic differences

when iv asked bout litening/balancing , iv been greeted with...we can do it for £xxx

wen ive asked qs about how much is taken off/how balanced are they etc............ ooooooooooooooooooh theres not a rite lot we can do to improve things really, waste of money



so i know a few of the difrences, and thats just visual difs, but not internals..

1 for ben i think hehe

 

[Ben H]

The original Williams lump was a low-volume parts bin special and Im sure that some of the special features wouldnt have made onto the mass produced F7R engine of the Megane simply because of the expense of mass producing them.

Most of the bits specific to the Willy F7R disappeared on the Megane and Spider F7R - but are mainly to do with the head and breathing. E.g. Willy has polished inlet parts, fabricated steel manifold, resin coated head, bigger inlet valves, sharper cams etc. None of these were found on the other F7Rs.

As for the bottom end, I think there are less differences. I know for sure that the Willy 1 had thinner compression rings than the F7P with special diameter piston rings, chrome plated twin-lip oil control rings and a fully baffled sump. Not sure if these changes over the F7P made it into the Megane/Spider F7R bottom end, but I think its unlikely due to the expense.

 

[BenR]

difference between F7Rs, not Rs and Ps ben lol.

And polished inlet parts????? where?
resin coated?

The blocks are quite differnt in their casting, strenthning ribs mostly. and some bolt holes.

Front covers are the same though.

cranks are different parts (willy ebing the diesel one), but physically the same.

rods the same.

Pistons are the same (depending on markings) as with rings.

And the sumps are different. The willy has a baffled bit.

And when you ask about balancing, you cant ever say how much your going to take off. It totally depends on the part weight and balance.

Anything i missed out?

 

[Smokey]

Yes, how long does it take to boil an egg??

 

[BenR]

hard or soft?

 

[2 live]

Quote: Originally posted by BenR on 04 February 2004


difference between F7Rs, not Rs and Ps ben lol.

And polished inlet parts????? where?
resin coated?

The blocks are quite differnt in their casting, strenthning ribs mostly. and some bolt holes.

Front covers are the same though.

cranks are different parts (willy ebing the diesel one), but physically the same.

rods the same.

Pistons are the same (depending on markings) as with rings.

And the sumps are different. The willy has a baffled bit.

And when you ask about balancing, you cant ever say how much your going to take off. It totally depends on the part weight and balance.

Anything i missed out?

well that pretty much covers the difs ive seen too, mainly being the stregnthning veigns(spelling?) at the rear of the block

iv also been told that he crank on the willy is def diff to the megane, and both are def diff to the diesel one................lol

seems to be so many ppl offering their services without actually knowing what the difrences in the engines reallyare , i.e in relation to tuning



oh and pistons..........the arrows on the megane are facing the oposite direction to the willy 1s.....i think,neither engine seems to have had a rebuild

as for wanting to know how much weight we were talkin in the litening/balancin thing, i was just wondering how much theyd lighten the flywheel by, obviously the rods can only be lightened to what the lightest rod weighs(without compromising stregnth a great deal), an u not gunna know that until uv weighed them all lol

as for te flywheel, mine weighs 5.4 kgs with all he bols, jus wanted to know how light they went with em cos they not exactly the heaviest to start with are they? lol

and the heads are totally diffrnt too hehe............which would explain why they make dif torque/power .............and by lookin at them the inlet valves on the megane seem to be slightly bigger than the willy 1s .............but the inlet tracts is where most of the dif is noticable, which would explain why the megane head is better for use with throttle bodies when youve seen it

 

[BenR]

Debatable.....the megane head has a better port shape for more linear torque spread, but in top end power utilizasions the large oval port of the willy/16v is better, but were talking about 300bhp.

THe 16V has 30.7mm inlet, willy 31.6 and meg 32-ish.....the diff in power due to valve sizes is minimal. Cams and capcacity make more of a diff.

THe crank in the willy is deffo the diesel one, its the same part, and the megane one is thesame dimentions, but NOT the same contruction.

And when you do rods you can remove the casting ribs (reducing stress risers), lighten, shot peen to reduce surface tension and balance.

And arrows should always point to the flywheel side, but ill double check this.

 

[stan*]

actually, cams (increasin lift) give an increase in power for the same reason that a larger valve diameter does----larger curtain area.

again duration and overlap achieve better flow through head

power is virtually determined by the cylinder head. if u put a willy head on a 1.8, in theory it will produce the same power, it just has 2 rev higher.

its all about flow thru the head!

shot peening actually increases surface tension

 

[BenR]

Were very much going back to basics with all this.

where power is a function of the amount of air you can process per unit time, or as Mike Costin put it "size of the bangs times the number of bangs per minute".

Larger curtain area s a function of increased lift with teh same valve sizes, but you can incraese power by simply changing the area of peak VE and the tailoff of a reasonable VE value.

Increasing valve area is ultimately better than increasing pure curtain area as a poppet valve of these sizes reaches a near finite flow rate and when compared to the much higher valve train loadings your running from higer spring seat pressures its really not worth it.

And wih the willy and 16V issue, for the power output, each head is capable of it. SO to get the 1.8 to produce 150bhp you dont have to increase its rpm limits.......but when talking absolute peak power, same head, lower capacity you need to rev it more to make the same as a higer capacity engine.

But weve all talked about this yonks ago in great detail.

 

[BenR]

lol, change your post while i type....cheeky sod, lol.

 

[stan*]

how is increasing valve area better than increasing pure curtain area?? the whole point of increasing valve size (area) and valve lift, IS TO increase curtain area.

wot do u mean by "u can increase power by simply changing the area of peak VE and the tail off of a reasonable VE value"?? doesnt really make much sense

 

[Ben H]

I was talking about the differences between the Megane F7R and Willy F7R! Just I think that some of the differences between the F7P and Willy F7R didnt make it onto the Megane F7R!

I got the info about the polished inlet parts etc from the 1993 CCC feature on the Willy. Lots of detail there!

 

[stan*]

sorry!! it needed tweaking!!

 

[BenR]

Quote: Originally posted by Ben H on 05 February 2004


I was talking about the differences between the Megane F7R and Willy F7R! Just I think that some of the differences between the F7P and Willy F7R didnt make it onto the Megane F7R!

I got the info about the polished inlet parts etc from the 1993 CCC feature on the Willy. Lots of detail there!

Look at them, they aint touched by hand.

 

[BenR]

Quote: Originally posted by stan* on 05 February 2004


how is increasing valve area better than increasing pure curtain area?? the whole point of increasing valve size (area) and valve lift, IS TO increase curtain area.

wot do u mean by "u can increase power by simply changing the area of peak VE and the tail off of a reasonable VE value"?? doesnt really make much sense

If you continue to increase lift sure you will increase curtain area, but beyond about 25-30% of the valves dia in lift flow tails off. So in real world operations a large valve with lower lift will flow more than a small valve with more lift but the same curtain area.

PLUS, when you bring the realities of engine building continuing to increase lift brings on massive valve train strain, plus the cam ramps and flanks become so agressive that massive seat preassure are needed to reduce bounce and float.

And for teh VE comment....simply put, by increasing the rpm at which peak VE occurs, more work done and BHP is the result. And since peak VE doesnt occur that close to peak BHP, you have a VE tailoff. This rate of decay is important to your power graph, where the rate of decay is faster (or not) than the increase in rpm after the peak VE point.

geddit?

 

[2 live]

ah yes but lookin at the heads, there isnt a rite lot u can do with valve sizes without having to pocket the block on the bores............



so back to original question hehe



blocks............and why is there so many conflicting stories from difrent tuners? the guy who was originally gunna do mine told me that the gains would be minimal (at most) and cost not cheap,and would lose me low down torque to boot .. whereas other companies are tellin me......yeah send it to us, well be able to get it loads better.......then retracting that statement and tellin me its hardly worthwhile

well after id asked a few questions that the 1st guy told me to ask (hes an engineer for kenny roberts racing), but also bin told the same thing from my local reno garage mech(since 1986 and been on quite poss evry reno course u can)



who to believe?????????

 

[stan*]

benR-

the reason flow tails if u continue to increase lift is that beyond valve lift = diameter/4, the port becomes the restriction; not the valve. so when u plot CFM against l/d, it rises steadily then flattens off when l/d = 4.

 

[Fred@BTM]

anyone got an asprin???

 

[dezRT]

Pistons, cams, valves, its all above me, all I know is I put petrol in my car it goes, if I dont put petrol in the car, itll stop.

 

[stan*]

enough bout engines!! any1 know any decent free p**n sites?!!

 

[BenR]

Quote: Originally posted by stan* on 06 February 2004


benR-

the reason flow tails if u continue to increase lift is that beyond valve lift = diameter/4, the port becomes the restriction; not the valve. so when u plot CFM against l/d, it rises steadily then flattens off when l/d = 4.

RIght......if port flow becomes a restriction above x lift then how come you can continue to make power power by using more rpm?

Surely if port restrction is a set CFM value then incresed RPM will yeild no more power. But it does........suffice to say were not talking about being at the total flow limit of the valve size.

And it seems as if youve been reading a few books or something as your not taking into account the dynamics of and engine, the theory your referring to is more akin to a static flow test.

IN a working engine, if you can keep the port flowing with increasing lift and the port does not become a factor then youll be reaching 100% VE very early....leaving a short duration of valve time open needed, thus this just leave more rppm for more RPM, and thus power.

Your singling out far too many simple factors and not bringing the rest into it.

How much have you actually done with an engine (a simple query, not a slap in the face).

 

[stan*]

not reading any books mate!! going on wot ive learnt from practical AND theoretical lectures.

power is a product of torquexspeed. so if u increase speed, power is going 2 rise regardless of torque (determined by VE as discussed on renaultsport).

tell me how to get pi symbol up and ill show u how port becomes restriction......

 

[stan*]

f**k it! let # = pi (22/7) (not steak+kidney!)

right, area of neck of port at valve seat= #(d^2)/4 (area of circle)

curtain area = #d.l

so, when l=d/4, curtain area = #d.(d/4)= #(d^2)/4

so, when lift goes beyond a quarter of of th port diameter (neck of port at valve seat), the port is the restriction.

if u have ever gasflowed a head (or at least planned 2), u should now that 2 balance the restriction of the head, u make the ports 4 times max valve lift. thats before u even consider shape/finnish.

 

[BenR]

See, this is what i mean.....

another uni student who goes bonkers trying to proove stuff.

Not bad though and nobody is complaining.

And just ot keep your brain buzzing, Dr.Rick Roberts created a formula to determine flow data. This was based on flow quality where the normal flow = dia vs lift. What was talked about was the area of flow quality and if valve diameter or curtain area was most important. So far, its regarded that valve Diameter is of more use in racing applications. If you can find his publishings its a fun read, but its not standardised yet.

DUnno how to get pi up, post the forumula up but what does it prove, nothing, we all know that when lift is high enough youll reach the finite flow of the port, but whats the point of lifting the valve that high.....it provides no benefit.

When were building performance engines you have to take into account alot more than just flow @ x lift. Sure, flow is the be alla nd end all of total power production, but managing that flow is 75% of the game.

 

[stan*]

mate, im not being a uni student trying 2 prove stuff.

is that wot u say to every one with an education that tries to prove something u dont believe/understand.

if u dont agree with me, fair dos. but its logic aswell as personal opinion

 

[BenR]

No sir, im not disagreeing, at no point did i say your formula is wrong, or what you area saying (when speciaised to that particular area) is wrong. BUt why should it be, it cant be...not with them teaching it to you.

Im not doubting your education, but so far you have said nothing but what the book teaches you. this formula, that formula.............people use formula to try baffle/impress others in such instances.

But when it comes to building engines when your not given a clean sheet of paper, i.e. current production ones, you havent even mentioned any other factors.

 

[stan*]

im not just telling u wot the book teaches, im tellin g u wot ive found from engine dynomometer tests, as well as flowbench tests. therefore both static and dynamic situations are covered

 

[paddymph]

kin ell jon, wat u tryin to do?!?

 

[jimbo1]

the cylinder heads r the main difference between the two engines. megane runs 32.9 mm inlet valves whereas williams runs 32mm. the inlet ports on megane head r smaller, therefore using a different inlet manifold and throttle body setup. it also uses individual coils rather than distibutor igniton system. the cams r same across the williams and megane f7r.

the blocks are pretty much identical. the megane f7r doesnt include an oil cooler as standard, whereas the williams f7r runs quite a big one as standard. the block castings r pretty much the same, the megane has f7r cast into the rear of the block. the internal coolant ways r slightly different, the megane having a different coolant path at the top of the block where it joins the head, but this matches up to other f7 heads fine.

the williams and megane cranks r the same, listed as kangoo part numbers on the renault parts database. the later IDE meganes used a new spec crank with chain drive for the oil pump, but ya dont wanna go there!

jimbo

 

[BUTRE]

so...

megane head better for a torque/bhp relation throught all rpm range.
Any F7R has got a tracktor sh*ty crank
We cant learn everything from books, but its a start.
We all love high quality p**n.

 

[2 live]

lol the nuclear phycisists above are a bit far out lol

how they get on about valves n head flow wen i asked bout blocks is anyones guess lol

no offeence meant guys but wot ur debating on has no relevance to the question asked, or has it actually taught me anything........xept that formulas are still a load of fukt up letters n numbers lol

 

[BenR]

your questions were answered were they not?

and a nice debate is always fun

 

[stan*]

exactly! BTW it wasnt a formula, it was proof!!!

 

[2 live]

lol yeah it was very intresting reading lol

and my qs were answered in a round about way hehe

but isnt it true that a formula can be made to prove anything?

a little like statistics hehe