URG8RB8

Patrick:

Albert is making the intake for me. He has all my specifications. I am letting him run with it. He promised me that if I don't like it he will take it back no charge. After 35 years, I am going to respect his experience.

I have to admit though, I am a bit intrigued by Rex's ITB carbon fiber rendering on FB. Has a long way to go but if the end result looks anything like the rendering, and the performance is good, I wouldn't mind one of those.

333pg333

Can someone confirm if this is an early or late version tensioner? I think late.

Van

I think earlier tension era are steel, late ones are aluminum. That looks aluminum.

333pg333

Sounds good Eric. I'm glad Albert has raised his profile and contactability on that FB page. He lends a lot of experience to the 944 world and I think he's had his 'eyes opened' just a little too.

Rex's product looks very promising. I hope it makes it to production. I know of a few options for our cars that might be available in the not too distant future which is a whole lot more than there use do be!

Thanks Van. I think you're right.

Paulyy

Tensioner looks like mine patrick.

333pg333

Thanks Pauly. Our one is Alu. Yours?

Voith

I have two tensioners like this, one is from 89 turbo, the other from 89 2.7.

Paulyy

Aluminium also

333pg333

Thanks guys.

Dutch944

Indeed late, my old engine had the manual..

URG8RB8

Mine is an '89 and it is aluminum as well, Eddie's is too.

333pg333

Yep, ours is a later model, thanks all.

So we've ordered the new pistons and rods. Neil has designed these so they have a relatively stock stroke but will be quite a bit lighter and have better weight distribution with a smaller pin and raised higher in the piston which will have shorter skirts. He feels that this motor will rev out to 8000rpm and that the intake will be the limiting factor. So we're going to make a new intake or perhaps use one that is being built for Gustaf's car. Once we finish the 16v motor we might put this one up for sale or keep it as a spare. I am looking forward to seeing how different this 8v motor will be compared to the last one. It will be only about 2.5ltr though with the 102mm pistons. We are going to try Neil's 'sealing system' too. Sort of similar to ours but the O rings are in the head, not sleeves.

URG8RB8

Just spoke with Neil, the lead time on the sealing rings is very long!

Sounds like my crank.

333pg333

So we've had a bit more progress on the 8v motor. Rods have arrived and pistons not too far away. Compression ratio will be 9:1 which is the highest I've heard on a 8v motor. Only running E85 race grade fuel so I feel fine with this. Should be interesting. Going down in CC from 3.1ltr to 2.5ltr with a motor targeting 8000rpm cut out would suggest that we will lose out on some early to mid range tq. However I'm thinking that the c/r will make up some response out of corners.

I've also been in discussing with someone else about making an intake for this motor and his assessment is that with the head being such a good flowing one we won't hit a choke point on this and his feeling is that we can go with a longer than expected runner which will also help with lower down tq. He's working on the length of the runners in harmonic values with all the data I've given him.

Really should be an interesting 8v motor.



NA Block
Doweled Girdle
Line bore checked
Polished internally
Deck plate fitted
Steel liners fitted and honed to 102.00mm
Race prepped Bearings
Bull nosed Crankshaft with narrowed journals, balanced to new Piston and Rod weights
Carrillo Rods, increased CCL to suit shorter Piston Comp height
CP lightweight boxed strutted Pistons with DLC pins, gas ported for low tension ring set
Piston Oiling Valves fitted
9/16” ARP head studs with 12 point nuts

Updated for late tensioner assy
NA 2V Cylinder head
Ported both sides
49.00mm x 5/16” Intake Valves
43.500mm x 5/16” Exhaust Valves
Ampco 45 valve seats
Ampco 45 valve guides
PD race valve springs
PD Titanium Valve Spring Retainers
PD Titanium Valve Locks
Stainless Exhaust studs
Machined for stepped head washers
PD stepped head washers
Arrow solid Cam Followers
PD Camshaft
Modified cam housing

At 28" test pressure

Intake Exhaust
0.050 47 26
0.100 82.5 59
0.150 114 92
0.200 141 111
0.250 163 133
0.300 187 151
0.350 212 171
0.400 235 182
0.450 257 192
0.500 265 200
0.550 273 206
0.600 279 211

"This head keeps flowing. The cam lifts are 0.595 and 0.526". So disregard
the flow numbers above these lifts. But it shows this head does not go into
choke even up to 0.600" lift. The exhaust goes sonic even on the bench so I
know the velocity is high. You can hear it crack!"

Paulyy

I dont think it'll choke, Planning on a gtx3076r? 20psi and it shouldn't drop off at redline. it'll flow 60lb/min at that pressure.