http://www.youtube.com/watch?v=M2KZByFivwU

It's not going to make it into the highlight video, but I couldn't just not upload it.

 

LOLz...you werent kidding. all brap. Hows that engine doing? Ive been trying to get ahold of you.

 

sweet! mine used to alternate between a steady brap brap and that brap buh buh buh brap idle too, until i richened it up a tad, now its like a machine gun

 

My phone's been a POS.

Still running about the same as when it went in 13,000mi ago, same compression, still holding coolant. Funny thing though, I have to change the coolant frequently. because the scuzzy crap all over the inside keeps dissolving into the coolant and it doesn't take long for the coolant to turn into a brownish-green nastiness. That just means it will take less effort to clean up when I turn it into a 4-port.

 

Sound's good, Watchd the other vids, Look's like a lot of fun !

 

You realllly like zip ties.

 

^ You don't?

 

Not really... there's just the ones holding the MS box to the dash (quick fix during an event - ECU was overheating and shutting the engine off after ~120sec on a ~150sec course, needed to get it off of the floor) and the one in the vents that holds the underhood-style vacuum gauge when I'm checking exhaust backpressure.

Do YOU know what your exhaust backpressure is? I know what mine is...

 

I like the idea of taking a bolt from a beehive engine (the oil banjo hole location on the rear plate, lower corner), drilling/tapping an NPT hole, threading in a brass fitting and a copper line or whatever that handles heat, routing it up to a boost gauge, going for a drive and seeing what your backpressure really is.

The beehive bolt threads into any standard O2 bung in your exhaust and they're cheap and plentiful if you're into 1st gens. Short length, perfect size, soft steel makes them easy to work with, unlike typical SS O2 blockoff bolts you find online.

 

the FD diff fill plug also works

 

That just leaves the FC guys.

 

1/8npt to 3/16 brake line adapter, and 6" or so of brake line. After that it can be rubber hose.

I've driven to and from the dragstrip (~50mi each way) and made a half-dozen passes or so like this. No actual hot air goes up the hose, since it is a dead end, so all you need to worry about is conducted heat, which is minimal. The main reason for that much hardline is to make it easy to bend it so the rubber hose never gets draped over the exhaust system.

My car runs open-loop all the time, so the O2 being out is not an issue.

 

How much backpressure see under full throttle?

 

I forget now, but I'm pretty sure it's 4psi of backpressure over 4 or 5,000. It doesn't ramp up though, which is weird - it just goes from 0 to 4 and stays there. Maybe that's just because the backpressure is keeping the intake from working effectively, so the engine can't move enough air to make the exhaust pressure higher, in a self-correcting action like an inverse wastegate.

So i know my exhaust system is too restrictive, which is part of why this engine with the heavy rotor housing reliefs is not as happy with the exhaust as the last half-bridge was, which had no reliefs. But that engine was way better than the street ports were, so there's my middle ground: half bridge good, but relieved eyebrows are too much for a streetable exhaust.

Bought an interesting book last week. In it he pointed out that, due to proper exhaust scavenging, pressure wave tuning, and intake runner design, a Cup car can see 80mph intake port velocity while the piston is still at TDC. That's almost all due to the exhaust pulling the intake change into the cylinder.

 

You know what... I have an extra boost/vacuum gauge laying around and all I have in my 02 bung is a bad wideband 02 sensor...

and yes it is an FC...

LET SCIENCE BEGIN!

but I have to wait on readings, engine is out of car to fix leaks and etc.

also did you check your coolant overflow reservoir? that always gets dirty for me and then ends up getting in the rest of the system.

 

my stock FC was like that, the backpressure ramped up, but the ramp was short and steep.

 

I've never ever had an issue with that.

The mud I mentioned earlier is coming from the cooling system. Trust me, the corrosion and slime in the water jackets was incredible. Russ above knows the full details, but IIRC the car that the current engine came from sat in a barn in Texas for 19 years. It was like lime Jello in the jackets. Lots and lots of wire brushing to get them usable.

Right Stuff and the McMaster-Carr cord O-rings and still holding up despite severe pitting in the water jackets and on the iron housings.