today i was really bored, so i went out and got one of the 3 extra 86-88 intake setups i have, i found a grinding bit i had and looked over the manifold, the bit was about 1/2" to 3?4" bigger than the small ports in the middle, i thought WOOHOO, so i spent an hour and a half grinding away with a cheap *** drill i was very please with how it all came out, i took the dynamic chamber off and ported that area, those ports going down are now almost as big as the ports on the outside, go to where the upper and lower manifolds meets, spent some time there, got them to where i felt they were ok and they look just a tad smaller than the outter ports, same with the lower manifold, i went far enough down in the runner on the lower piece to get rid of that little hill that is made from the ACV bolt that is there, it has a little hump in the intake, i smoothed that out, tomorrow im going to get some more bits and make the outter ports just a tad bigger, and im going to do some more work on the inner ports, my dad is gonna grind that little lip out of the TB elbow for me, and im gonna do some TB grinding, im also getting some 3" PVC pipe tomorrow to replace the 2.5" alum intake tube i have on my car now. i hope to at the very least get 5hp from it, i think i can get around 10hp if i can find a grinding bit that will be about 1/2" bigger around than the outter ports and do some more work on the inner ports, im gonna get some of those plumbers wire brushes and clean out the intake ports on the engine when i remove the intake to put the ported one on it. im gonna try to find a way to keep my 6 port sleeves in there without have the 6 pi actuator system on there, i need to find a way to wedge them in there so they stay open and dont vibrate shut when im driving, or i might just leave them out. if i had the bolts for my air pump i would put it back on and make my 6 ports work, but oh well i need to get a new fuel filter and put it on, change my tranny/diff oil, and engine oil, get tires balanced and do an alignment. i think thats all my plans this weekend if you got any ideas on the intake let me know.

 

any comments?? lol

 

I was told by Rob at Pinnaple to use loctite to keep the racing sleeves in place, I'm sure the same could be said for the stock sleeves

 

ooooh, thank you much

 

Take some digital pictures for us. I was also wondering how I can get the pinaple sleeves in thier without the rod holding them in... Like Mabey glue or somethin. JB weld. But im also going to do this.

Question... On the dynamic chamber runners and the lower manifold. How do I port the runners so thier even all the way through. I would need a miniture hone or somthing right??? I want to maintain an even diameter through the runners. The dremel cant fit all the way inside. Know what im sayin???????

 

I am doing the same thing. the outer ports on the lower on the motor side was about 3/4" diameter. I have made them 1.1" diameter, and improved the transition form the single hole into the tow on each side. I have also estensivly ported the runnerson the upper by taking on of those flex shafts for cordless skrew drivers and modified it to take a sanding drum. this way I can get to the ceter of the runners easy. I smoothed transition from down to side draft in the upper too and cut away alot of metal around the injector holes on the upper, this is angled from top to bottom to reduce restriction. I have had fun doing it too. but I have gone thru 4 packages of the dremel saning drums. they don't last at all

 

oooo loctite. Max wins again!

 

For a little extra hp, match the manifold to the ports on the motor. That will cut down on turbulence just before entering the engine.

 

ya... good idea

What kind of locktite????

 

No way, that will KILL your torque everywhere!

You WANT the runners in the engine to be a bit bigger than the ones in the intake manifold. The little "step" goes a LONG way to preserving torque, not just down low but everywhere else. It acts like a check valve, air easily flows into the engine but it doesn't easily flow back up to the manifold. If you eliminate the step you eliminate that check valve effect - massive loss of torque.

This is probably only important on the primary runners. Since the secondary side is designed to USE the reversion to force more air into the other rotor, port-matching the secondary side is probably OK. But definitely leave the primaries alone!

BTW - My 12A (i know, i know) would go from 30-50mph in just under 7 seconds, in 5th gear! That calculates to an AVERAGE torque of over 100lb-ft between 1500 and 2500, with most of the torque coming on over 2k, so I was probably seeing 110-120lb-ft at 2500. Not bad for an engine that was 100lb-ft peak at 4k stock! How did I do it? Maintained intake velocity in the primary runners by only smoothing them out and NOT port-matching them. FWIW the runners in a 12A manifold are about HALF the area of the runners in the engine on the primary side. Probably could have opened them up a little bit but another thing you have to worry about when porting is doing any modifications in areas that curve. Do it wrong and you can easily set up pockets of high turbolence. Without a flowbench and ways of "seeing" turbulence I'd be VERY careful. As a general rule though, for runners that have to curve, don't modify the short side of the curve. If anything, add material to it to make the runner D-shaped instead of round, with the flat part as the short side. This lengthens the short-side radius without hurting flow, meaning velocity goes up = torque goes up = HP goes up!

I might've said too much

 

Ok. So on the big secondaries go ahead and port them big and leave port the ingine side a little bigger. But leave the primaries only smoothed out and same size with same size manifold to engine.???? is that what ur saying..???

 

peejay said - As a general rule though, for runners that have to curve, don't modify the short side of the curve. If anything, add material to it to make the runner D-shaped instead of round, with the flat part as the short side. This lengthens the short-side radius without hurting flow, meaning velocity goes up = torque goes up = HP goes up!


Thats good sounding advice. It has given me something to think about.

 

You don't want to port match the primarys (the middle pair). You want the intake manifold runner to be a little smaller than the engine runner, for the check-valve effect (actually it's anti-reversionary). The secondary is probably OK to port-match.

 

Oh... ok. I get it. Thnx alot.

 

ok here are a few pics i havent ported the outter side of the manifold yet, but the middle ports are almost finished, and i got a few pics of the TB and what i did to the dynamic chamber.

 

another

 

just a few more

 

almost done

 

gosh this takes forever

 

la la la

 

2 more, yay

 

last one finally

 

bump

 

good job, haha, i've been thinking about doing this when i get a VDI to slap on my 88, anyone know if the lower manifold off the VDI will bolt on to my 88 block? if not, how hard is it to make it? thanks

 

in the third pis those little post with the screen on the end what are they for?? do they need to be there?? and how come on one set they are their but on the other, the one you ported they are gone??



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