Mazdasly75's GT-R

[b19gtr]

I used a piston to cylinder clearance of 0.004", 1st ring end gap 0.028" and 2nd 0.019"

Are you sure this is right Sly, because usually the top ring gap is smaller than the second ring gap to avoid blowby.

[mazdasly75]

lol, yeah you're right, after looking at my sheets I inverted the spec of the ring gap.

[b19gtr]

Do you have a guide of how to set the timing with a degree wheel etc? It would be really useful for me.

Thanks

[mazdasly75]

Do you have a guide of how to set the timing with a degree wheel etc? It would be really useful for me.

Thanks

It's sad cause I've lost the pictures, but once the degree wheel installed, you need a dial indicator set on the valves of the cylinder no.1, to find the base setting. Or, you can use the base data from the manual, then start from here.

The thing is, to retard the cam to lower the exhaust gas temperature past 6000rpm. That thing jump from 1250F to 1500F in only 1000rpm at 20psi. With a retard of 5 degree on the exhaust cam and 10 on the intake, it will not only remove completely overlap but also will lower the EGT down to 1400F running on 93 octane with an AFR of 11.5, you should be able to run 14 degree of advance in the map pass 7000rpm.

[b19gtr]

It's sad cause I've lost the pictures, but once the degree wheel installed, you need a dial indicator set on the valves of the cylinder no.1, to find the base setting. Or, you can use the base data from the manual, then start from here.

The thing is, to retard the cam to lower the exhaust gas temperature past 6000rpm. That thing jump from 1250F to 1500F in only 1000rpm at 20psi. With a retard of 5 degree on the exhaust cam and 10 on the intake, it will not only remove completely overlap but also will lower the EGT down to 1400F running on 93 octane with an AFR of 11.5, you should be able to run 14 degree of advance in the map pass 7000rpm.

Thanks for the reply, am i right in saying, to advance the timing, the camshaft is rotated clockwise and to retard anti-clockwise, setting the ignition timing is the opposite, it all seems very confusing.

[mazdasly75]

Here's an update!

yesterday I finished the manifold by welding the external wastegate, and installed the manifold and the turbo. Here's few pics again, enjoy

Welding the elbow took me 2 hours!! was so close, the TIG's torche couldn't reach everywhere. Had to extend the tungsten a little bit to reach the middle of the collector merge.














From the inside, the hole made with my plasma cutter, ground a little for a nice finish




Then I welded 2 littles braces to give the manifold more strength, to help the welds resist the vibration. If you look carefully, every bolts clears perfectly to be torqued with wrench and ratchet.




Now with the wastegate...




Here's a port the will get cooked
















Here's a picture with the turbo installed...but from the underneath of the car only, you see the custom oil/water hoses. I had to leave at that time so I forgot the take few shots of the turbo...

[FE3-323]

do me a favor please. take the top off of the wastegate. pull the guts out so you can rotate the lower portion of the top & move that line away from the manifold. no rubber out there could withstand that heat.

[DuRWooD]

Here's an update!

yesterday I finished the manifold by welding the external wastegate, and installed the manifold and the turbo. Here's few pics again, enjoy

Welding the elbow took me 2 hours!! was so close, the TIG's torche couldn't reach everywhere. Had to extend the tungsten a little bit to reach the middle of the collector merge.

Nice update man, looks like good work. I've been waiting to see what comes next.

do me a favor please. take the top off of the wastegate. pull the guts out so you can rotate the lower portion of the top & move that line away from the manifold. no rubber out there could withstand that heat.

Looks like it could just be rotated 180 degrees.

[FE3-323]

no durwood, your not following what im saying.
the aluminum top hat of it is 2 portions. its held down to the lower steel portion by a retaining nut usually- sometimes allen keys.
The valve/spring/diaphragm are all held in the AL top hat mess they can be rotated without harm (most people aren't aware of this)

[mazdasly75]

The top portion of the wastegate clear the exhaust and can be rotated, but the bottom portion can't move and this is why it has an elbow on it. It will stay like that for now, but in the next days, I'll drill another hole and block the one that's face the manifold. It's 1/8" NPT so nothing complicated.

Thanks for your advice though, I appreciate it

[FE3-323]

no. it can be rotated. thats in the design of all external wastegates.
regardless if you redrill/tap it you'll need to tear it down enough to see that anyhow just to clean the shavings out

[DuRWooD]

I see what you're saying now, I rotated my GReddy BOV like that. So yeah, easy to do.

[FE3-323]

looking a few pages back. I really like the crankshaft lightening. how much material did you remove from the crankshaft? what was its overall end weight???

are those pistons forged???

[mazdasly75]

I dismantled the whole thing, I first though I could rotate it, I can tell you the bottom part can't rotate cause it's fixed by 3 bolts on the casted part; there's 2 holes at 1" of each others and the last one is 2" away from the others, it's not like "equilateral triangle" style, if you understand what I mean...

The crankshaft lost almost 5lbs. It was 36lbs before the knife edge job. The supertech pistons are forged and way more stronger than JE, they're beefer and the piston pin is also bigger in it's diameter. The piston's looks like that cause of the coating supertech use on it.

[FE3-323]

i stand corrected on the wastegate then!!

i really do dig the crankshaft it looks a professional job for sure.
how do you figure the pistons are stronger than JE? and please explain the piston pin. is it the same diameter. but thicker?? or is it made of tool steel instead of chromoly??