VVT head + 94 block + real OPG + turbo oil line
 

1) Will the oil source line for the VVT oil control valve bolt to the the 94 block no problem.

2) My turbo oil source will be on the exhaust side of the block (it's a 94 block after all). I'm thinking of mounting the real Oil Pressure Gauge sender onto the turbo oil line at the turbo end. What fittings will I need?

3) Are there still 8.8:1 factory pistons available from Mazda?

How about if I want to install a turbo oil feed and a real OPG to a VVT motor?

not sure if the boss for the hardline is there on the earlier cars.

94 stock pistons are 8.8 and slightly dished. later cars are higher.

I ran the oil feed/gauge from the original sender location. lots of stuff hanging off there, but so what.

Isn't the boss on the block for the VVT oil hardline the same boss as the oil pressure switch on the earlier cars?

i never looked. svc manual shows it in a boss that appears to be right under the pressure sender... right behind the oil filter. huh.

94-97 blocks should have the oil port on the hotside. Beware hanging lots of stuff off one oil fitting on the side of the block. Vibration tends to kills those in track cars. First thing we do is fit a distribution block on the firewall. At the very least, make sure the thingy on the block is steel, not brass.

emilio, you're talking about the oil port for the turbo. On the 94-97, there's a capped off port under the exhaust mani.

I'm asking about

1) how to add a real OPG sender AND a turbo oil source tee, to a VVT block
2) same thing, for a non VVT block.

Jason, my understanding is that you would want to pull oil from the pressure sender to a distribution block so anything after 95 would be from the "cold side". Then from there add whatever you want. Feed for your turbo, temp sender, oil pressure sender what have you.

Ill probably be doing this on my new motor with:

Oil feed
Real oil pressure sender
Aftermarket oil pressure sender
Oil temp sender

The only thing i am a bit worried about would be pressure if i pulled it from both sides of my early 1.8 block. I plan to pull it all from the pressure sender side but have been toying with the idea of pulling just the oil feed from the exhaust side. Thoughts anyone?

Forgive me if I'm misunderstanding, as this seems like too simple of question.

Your concern, if I read correctly, relates to taking oil for the turbo from the fitting near the flywheel on the hot side of the block, and measuring pressure & temperature at the stock sensor location on the cold side.

This is (almost) exactly how it was designed to operate originally in the 323GTX, and how most of us with early blocks are running.

Or an I being obtuse?

The only thing that would concern me is temp sensing on the coldside. Reason is that you need a continuous flow of oil across the temp sensor, and you're not going to get that if you're measuring at the end of a dead line.

Perhaps a sandwich plate between the oil filter and cooler would be best for this? You could also place your aftermarket sensor here, though of course it will read slightly high as this location places it before the filter.

Basically yes, maybe it will be smarter to pull from from the "cold side" to a distribution block and out to the feed. That way everything is in-line and getting the same readings.

Oil temp reading should be taken from the sump.

I did the easy way out, I glued a sender bulb to the rear of the pan.

Why?

After 20 inches of turbo supply line the oil will have cooled down a lot.

I've oft wondered about this myself. In a situation where an oil cooler is present (such as the OE water/air unit on the '94+) is it better to take the oil's temp before or after the cooler?

Part of me wants to say take it before, as this is as close as you can get to measuring whatever the highest temp the oil achieved was, and thus how close it is to the breakdown point.

Another part of me wants to measure it after, for reasons that I can't quite quantify.

It wouldn't be 20 inches from the block, maybe 6-10 tops. I could even throw a T fitting right off the block.

The oil flow through the turbo is so slow I think 6-10 inches will cool it, especially since the hose has so much surface area in relation to the mass of the oil.

Joe: sump oil temp is pretty standard, and is what people compare with.

My 83 280ZX Turbo motor had an oil temp sender from the sump factory.

Also, people sell (or you could easily make) and sump sender adapter by using the oil pan drain bolt.

Does anyone have a decent diagram for oil flow through the motor? I pull oil temps off the pressure port under the IM and they are always super low - I haven't done any further testing to determine whether this is my stupidly-large oil cooler, or whether I'm just measuring oil that's come straight out of the cooler.