R8 G 1700 upgrade

Bustamif said:
Timing: Exhaust opens 81 degrees, closes 49, Inlet opens 46, closes 78, duration 240 degrees. Lift: inlet and exhaust .275 thou. There is 85 pound spring pressure on the seat.

The titanium retainers for the Manley springs are to suit 8 mm stem, .935 thou OD with 7 degree valve lock. The valve locks are SB Chev, LS/LT1.
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Given the long seat to seat duration and the 240 degrees at 50 thou, the cam is like the competition cams of Renault that lift and lower to the seat relatively gently and is perhaps a guide to cam longevity. Are your tappets flat as original or have a 2thou convex? I also use around 80-85lb on the seat and 220lb on the nose, again maybe not helping cam life.

From a flow bench test done long ago on one of my heads there is very little to be gained by lifting beyond 450thou, and at 412 your cam is more likely to stay in shape. From the flow bench figures, at 450thou lift at 7600rpm the head was capable of 180hp as a 1600.
 
Thanks Aln, they are standard tappets, I was hoping to get some roller rockers but the mob in the states don't seem to reply to emails from Aus. My aim is a reliable 180hp, the existing engine has about 140hp so it should make a big difference.
 
I have also emailed Rockerarms just yesterday. I might try a phone call if no reply. They aren't a necessity, just nice depending on the price of course. I do very much like your R8. A one off indeed.

My 4CV had 116Hp at the wheels last I ran it on the dyno, around 140Hp I guess. It will now get 17TS injection with a M4 Motec, but a bit smaller cam to produce maybe about the same I expect. Probably still a year away till it all gets put back together.
 
Agree on the roller rockers, I believe Shoji is still interested in a set so maybe the price could be OK for an order of 3 sets.

The R8 is definitely a one off, the progressive rate springs in the front work great on the track with al the other mods, Heim joints, adjustable sway bars etc. The car even has a soft, compliant ride over our Aussie roads with all the pot holes and corrugations. Mark King at Kings Springs used to make springs for me on special orders when he was building his reputation on race results. I have used most of my spares on projects and doubt I could get them made at a reasonable price these days.
 
The progressive rate springs, are they done through having coils close together that then bind to raise the rate, or with tapered wire?

My 4CV has had minimal development in the 30 years since I put it together. There are plenty of things that can be done to improve it, but would really only be for my satisfaction. It may go to a Hillclimb one day, and Happy Laps is fine, but it is a bit unstable currently at high speeds above 160kph.
 
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Aln said:
The progressive rate springs, are they done through having coils close together that then bind to raise the rate, or with tapered wire?

My 4CV has had minimal development in the 30 years since I put it together. There are plenty of things that can be done to improve it, but would really only be for my satisfaction. It may go to a Hillclimb one day, and Happy Laps is fine, but it is a bit unstable currently at high speeds above 160kph.
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It's tapered wire with some tricky calculations on the diameter to calculate the rate of change. The first couple of inches enables a soft spring, great in wet weather for front turn in and rear power down. It then binds up progressively but very quickly to the linear rate under load, such as on a race track. The front rate is about 400 lb inch from memory but it could be 250, memory is not that good without checking my log. Some people have used a similar theory by having two springs, a soft one that binds up then immediately transitions to the second stiffer spring. I prefer the single spring in tapered wire.
 
Aln said:
The progressive rate springs, are they done through having coils close together that then bind to raise the rate, or with tapered wire?

My 4CV has had minimal development in the 30 years since I put it together. There are plenty of things that can be done to improve it, but would really only be for my satisfaction. It may go to a Hillclimb one day, and Happy Laps is fine, but it is a bit unstable currently at high speeds above 160kph.
Click to expand...
Above..... :)
 
Interested to see the figures, if you get it tested. Never seen an asymmetric Cam in a Renault Engine. Always interested to see what does what. Asymmetric was all the rage in Siamese ported stuff, but many in the uk have gone back to symmetrical. As always everything works if you can figure out exactly how to get it all harmonised together. To be fair if any of us knew exactly how to do this, the world would be a much simpler place.
 
First 2 pictures below show the steel plug removed from head, ally tube formed to create water inlet to block and isolate water return/exit through head.
hc.jpg

h1.jpg


Completed head with fabricated water inlet/outlet manifold

h2.jpg

h3.jpg


Water to block now enters at the other end of the head. Note the combustion chamber shape is modified to suit the domed pistons with valve recesses.
h4.jpg

Water from block into head now enters head from the old water pump inlet end
h6.jpg

Water galleries opened out in the old water pump end allowing flow from block through head
h5.jpg

Ally plate to seal the old water pump area
H5b.jpg

Picture below, illustrates exhaust porting and the small diameter of valve springs and titanium retainers
h7.jpg
 
Bustamif said:
First 2 pictures below show the steel plug removed from head, ally tube formed to create water inlet to block and isolate water return/exit through head.
View attachment 233846
View attachment 233847

Completed head with fabricated water inlet/outlet manifold

View attachment 233848
View attachment 233849

Water to block now enters at the other end of the head. Note the combustion chamber shape is modified to suit the domed pistons with valve recesses.
View attachment 233850
Water from block into head now enters head from the old water pump inlet end
View attachment 233851
Water galleries opened out in the old water pump end allowing flow from block through head
View attachment 233852
Ally plate to seal the old water pump area
View attachment 233853
Picture below, illustrates exhaust porting and the small diameter of valve springs and titanium retainers
View attachment 233854
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That water pump work is gorgeous.
 
I am a new member in SE Qld chasing new steering parts for a 1970 Renault 10. These are
LH Front lower ball joint
RH front upper ball joint
Front sway bar end bushes

Could someone point me in the right direction for a supplier

Kind Regards
RobboRenno
Alan
 

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Robbo Renno said:
I am a new member in SE Qld chasing new steering parts for a 1970 Renault 10. These are
LH Front lower ball joint
RH front upper ball joint
Front sway bar end bushes

Could someone point me in the right direction for a supplier

Kind Regards
RobboRenno
Alan
Click to expand...
There are several suppliers in France. Of late some of us have used Arnaud Ventoux Pieces with satisfaction. Also Ichard, Mecaparts, Bretagne Auto Parts, Melun Retro Passion and Der Franzose are well known and mostly reliable. You might check Auto Paris in Melbourne and Colliers in Sydney, just in case...

If you are replacing ball joints, you'd be wise to check the inner pivot bushes of the upper and lower wishbones.

Are you lInked up with the Renault Car Club of Queensland? Great group.

Good luck.
 
Robbo Renno said:
I am a new member in SE Qld chasing new steering parts for a 1970 Renault 10. These are
LH Front lower ball joint
RH front upper ball joint
Front sway bar end bushes

Could someone point me in the right direction for a supplier

Kind Regards
RobboRenno
Alan
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This might belong in the "WTB / For sale section" froggy classifieds. I can move it there for you or let you post a new thread there?

Nice R10 btw.
 
Aln said:
I have also emailed Rockerarms just yesterday. I might try a phone call if no reply. They aren't a necessity, just nice depending on the price of course. I do very much like your R8. A one off indeed.

My 4CV had 116Hp at the wheels last I ran it on the dyno, around 140Hp I guess. It will now get 17TS injection with a M4 Motec, but a bit smaller cam to produce maybe about the same I expect. Probably still a year away till it all gets put back together.
Click to expand...
I've just Sent another email stating that a few of us would like sets
 
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