I recently ported my 6port spareengine
Im hoping to pull around 210 @ the flywheel

It will see a few trackdays and general abuse other than than its my daily driver.
I would like opinions on anything that you could think of.
Like how much could I go down(port) on the exhaustports, wetcoil reccomendations ASO
Current SPECS:
Cold Air intake
True dual exhaust
SAFC
550cc secondary injectors(I have them, just not sure if its overkill)
Euro spec motor (fully functional 5/6 ports) for low end
No emissions
Matched intake manifolds
Distributor dizzy(Euro-stock)

Bridgeport

Exhaustport

Polished rotors

 

oooooooooo...shinney!!!
EJ

 

Check the path of the leading corner of the side seal.
It looks as if it may be exposed to your widened port.
If so, polish a small rounded ramp just at the closing edge of the port so the side seal can't get pinched as it comes around.

Here's a trick: Connect the blue (PRS) lead of the S-AFC to the oxygen sensor signal.
The readings will need some interpretation, but you will be able to see the signal drop if it is starting to go lean at 3800.
If so you might want to use the 550's as primarys...

 

Thanks SS.
I used the plexiglass trick to check the sideseal path. Its supported just fine.
Thing is with Eurocars that they didnt come with an O2 sensor, can I just weld one in and use the signal wire only?

Kim

 

Nice job.
I'm surprised that E-specs have no O2 sensor.
Yes you can certainly add one near the start of the downpipe.
You can then use it to lean down your low throttle cruise map for better fuel mileage.

BTW: Make sure the bell housing to firewall ground is in good condition.

 

can you smooth out the intake ports anymore? (1st pic) I know it's a pretty 'detailed' picture, and it doesn't *really* matter TOO much... But still, just for the sake of aesthetic value or peace of mind?

So, on the exhaust ports; did you just grind out the diffuser? I used the RB exhaust port template on my s4 turbo housings (no diffuser) and it suggests extending the port down a little bit for better flow. I wish I had pics, but whatever.

 

Yeah I just cut out the bottom half of the diffuser.
I havent ported on the exhaustport yet as I have no idea on how far I shoulkd go.

 

Well if it helps ya any, I went down 4mm on my exhaust port and recently took it 2mm up (from stock opening).

I'd estimate the engine made 200 flywheel horsepower with the exhaust port only 4mm down and stock closing timing.

Here is the latest exhaust port with the last one next to it. The car pulled about .38 g in second from 5k up to 7.5k rpm; felt like a light twin engine airplane on takeoff. I'm hoping to get around 14 flat in the quarter with the latest port refinements and a real exhaust system.







The car was a blast on the most recent set of ports. Stiff chassis, weight distribution, POWER, easy temperament, man it was great. But my tension bolts started getting loose and I had an oil leak on a dowel pin o ring due to this. I keep having little details cost me an engine pull, but it gives me a chance to touch up the ports with my dremel, and try experiments.

Taking the exhaust down 4mm made the power band much flatter above 5k rpm, and I lost a little punch below 2.5k but the power felt about the same at 2.5k, and greater above that.

 

I might as well show the intakes here too, for those of u who don't like Nopistons (including me now, hehe)





Yep, that's what it takes to make a really gnarly FC NA six port engine. All I had was a cold air intake, RB streetable header, mild ported intake manifold and SAFC, and the car fu%king flew! I can't wait to get it reassembled and feel the new exhaust port timing.

 

what does a light twin engine plane on take off feel like.. im use to single :-P

 

Man you've removed and reported your engine a lot haven't you? Have you just reused the soft seals each time or did you actually replace them? I've actually been thinking of cracking my motor back open and going larger on the ports, I left a little more to be had (not much on the front/rear plates but a little on the intermediate). We should have a NW porting party or something

 

Im porting my spare plates,
I just wish I had some templates.

Whats the plexiglass trick? Im already planing on scoring and cutting out a peice the size of my rotor so make sure I am well within speck.

 

Cut your porting template onto the plexiglass with a hole through it for the E-shaft to go through, have the motor partially assembled with the rotor. Manually turn the engine and watch where the rotor goes, you can see where the sideseal and such travel and if they're going to catch an edge anywhere. If they do, bevel the port so it doesn't catch.

 

I've reused the soft seals so far but this time I'm changing all of them. They all looked fine but I'm not willing to keep pulling this damn thing. The RA apex seals still look great though and have .002in clearance in the rotors, so they will be reused.

Oh, and a light twin like a Beechcraft Baron feels pretty nice on takeoff, like a Cessna 152 x 1.5, or about like an RV4 with an O320 (150hp) engine. It's not like an airline plane taking off though, those things really get up and move. First gear feels about like that, but not second, and it's about .5-.6g.

 

Yah I'm sure the apex seals are fine, I was just more wondering about a one time opening/reporting if I could reuse the soft seals. From what I've read usually it's ok, just wanted to make sure.

One more porting job and I'll finish it the "right" way this time

 

Be sure to take some pix of the changes, I'd be interested in seeing them.

 

Only changes will be to move the front/rear plates up more and a big enough bevel to handle the sideseals, and then my intermediate plate will look VERY similar to yours

I'll take pics when I do it, though, that's for sure. Thinking of moving my exhaust port up a little more too, but I already moved it up 2mm and down about 4.5mm to 5mm, so that's pretty big.

 

Thanks alot for the pictures of your ports, that gave me confidence to get them done.

 

are there any side effects of polishing up the rotors like that? i would think that you'd see a very minute drop in compression ratio.

 

I seriously doubt that you could even measure the compression drop.
I did it because im too damn cheap to get them ceramic coated, the polished surface dessipates heat more effectively, keeping the heat in the combustion gasses and I think ive read somewhere that it will flow more the hotter it is.

 

A few pics of the most recent primary port touch-ups for your amusement:









A little angle change on the closing line, a little more backcutting, a little shallower exit ramp angle, etc. I've been surprised how big I've been able to go on the primaries in the past as long as I only went up and followed this basic bowl shape. Midrange power has always been great, so we'll see how this latest experiment pans out.

 

That's some pretty aggressive porting on the primaries, I give you props.

What a gradual angle back into the iron too! That should be plenty good support for the sideseals

Have you thought about shaving off a little more of the inclined wall off on the top part of the port (down at the end of the runner)? With that much of an incline it seems light you *might* be able to take some more of the wall off there for greater volume inside the end of that port. Not sure without being able to see them in person rather than in pictures, I know there is a coolant passage right there so I'm not sure how much of a wall is really left in between the two. Looks awesome either way.

 

Yeah kahren told me the same thing. I'm close to the water jacket as it is and I like to keep the volume low but the timing big. The closing edge is a ramp that radiuses right out onto the side plate. It flows great, judging by the fog path my breath left on the plate directly above the closing line when I blew through the runner. It directs airflow in the direction of the moving banana shaped chamber.

we'll see if it works, it should really move in the drag race power band (5-8k).

 

Yah definitely, I mean my ports pull pretty damn good on and my primary is mild. Still need to get back in that bitch! But I gotta get my FD first.

As for pulling to 8k, I hope you're able to. Damn n/a's have a rev limiter/fuel cut thing, not sure if it's actually a fuel cut as more of just a rev limiter but either way it sucks. I finally got done with the break in and was testing the ports out, it was pulling like CRAZY up until around 7.5k, kept pulling hard and at 7700 on the tach (which who knows where it really is since the stock tach at that point is inaccurate) the car just went from pulling like a madman to falling flat on its face as it bounced off the rev limiter.

Plus I need to shim my front OPR because I'm not getting as high of peak oil pressure yet with my upgraded rear OPR. Ignition is also kinda inaccurate at that point on stock ECU, I really just need to get a wolf 3d and pull to 8k without problems

 

Ive hit that revlimiter too
Got friggin scared the first time, as I didnt know that N/As had one.
Im thinking that it could be a fuelcut device of some kind as im running a dizzy instead of CAS.
If thats the case there must be some way to remove or override it.