Finally got a warm day to pull the intake and reseal the base.

So, of course, I'm going to take the siamese but another inch for a total of 2" depth; I hope to see another 10-20hp at 5,400rpm. With the 2,000rpm TC I have enough torque to spare at launch but want to rev higher in each gear.

Now, if I can just get those ^%*#(( gas lines capped to stop the seepage I'll be able to pull the fuel rail and base.

 

Good luck Jim.

The track will tell if you will gain or lose. Hopefully gain. :cheers:

 

I had the same problem with the fuel lines leaking. It was caused by pressure in the feul tank. I opened the cap to relieve the pressure and left it loose and the leak stopped.

 

Any updates ? Is the intake off yet ?

Vic

 

I used 1/2" heater hose over both fuel lines to stop the seepage, even with gas cap off.

Anyway, got the intake off, siamesed 1/2" deeper (couldn't take it anymore with the Dremel), cleaned up and ready to customize the lower runner gaskets to fit the siamese openings.

After I clean up the gasket surfaces on the engine, I hope to have the base on & torqued down tomorrow. I'll let her set overnight and retorque before installing the rest of the intake.

Then she sits for a copla days in this cold weather before I start her up.

If all goes well (no leaks) I hope to make some passes at Raceway Park this Sat & next Wed in prep for the CC operner on the 22nd.

 

Glad it's working out well.

Keep us posted.

Vic

 

I finally got a day with temps above low 30s so the RTV went down today noon and the base was torqued down just as the sprinkles started.

I'll retorque the base bolts tonight or tomorrow; then on the next warm day she goes together.

Of course it's never easy; I sheared a T-45 on bolt #11 so off to Sears for another Torx set (single T-45s N/A).

This time I hit the lands with #100 sandpaper, cleaned with carb cleaner followed by several wipes of laquer thinner.

I also laid a wider bead of RTV to minimize the chance of a gap or weak spot.

Hopefully by this Sat. I'll find out how she runs.

 

I'm not too far from you Jim. It is "TOLERABLE" temperaturewise today. Glad you got things done. And it sounds like "Whitie" will be ready to rip up the 1320 at the challenge. :cheers:

 

Jim

I threw those torx bolts out the first time I ever pulled my lower intake. They are the worst. Think about replacing them with regular 6 point SBC intake manifold bolts.

Vic

 

And didn't I see temp close to 60 degrees for this weekend(this of coarse on the heels of tomorrows 4"-6")

Good luck Jimbo


[Modified by chucks88, 7:09 PM 3/12/2003]

 

Sounds good. Keep us posted. :thumbs:

 

Broke another T-45 but she's been retorqued to 35 lb-ft; ready to resume assembly Fri (rain/snow tomorrow, of course).

So I'm still targeting Sat. evening at Raceway Park.

 

I have a queston about this modification, where do you make this cut and with what do you use to do it ? Is it done on a milling machine ? Is there a forum post with pictures of this mod ? thanks

 

:withstupid: That worked for me too. Initially I was baffled on how a half gallon managed to siphon out of my 1/4 full gas tank. Gas is supposedly REALLY BAD for RTV.

 

I've been considering getting one of those flexible extensions for my Dremel. It might make quick work of polishing up the insides of the alum intake runners and base.

And a few Questions:

How far did you siamese the 5-7 wall, and are you using individual runner tubes?

I guess the 5 can steal the 7's air if they're joined too close, because of their sequence in the firing order.

Is the whole point of this is to kill the tuning effect for the sake of increasing total flow... or to somehow change the tuning effect.. ie: make it happen at a higher engine speed?

 

black85vette, I have pics of my initial siamese base on my site but didn't take any pics of this cut.

I got the idea for this mod from some posts on the thirdgen.ogr forum and finally tried it on the Vette. Several others on this Forum have tryed this mod with good success. It's an inexpensive alternative to the aftermarket intake systems.

I used a cut off wheel on a drill for the initial cut followed by a straight cutter bit on the Dremel. On this pass I just used the cutter on the Dremel followed up by a few passes with a 60grit drum.

CentralCoaster, I used the flex extension on the Dremel as the base Dremel would be very difficult to work with at any depth.

On the first cut I made a 1/4" cut into the bottom of the runners and about a 3/4" cut into the intake base tubes at 1" high for a 1"x1" opening. I'm using stock base and stock runners though the runner tops and the plenum openings have been ported out as large as possible.

I had some concerns about 5-7 reversion but it doesn't seem to be a practicle issue.

The point of this mod is indeed to enhance top end RPM breathing by providing two runners to supply air over most of the path yet retain most of the low end torque by keeping the total runner length near stock. Since a cylinder pulls through short stock base runners but two stock runner lengths it's a modified TPI. This makes the tuning more complex than stock since the air velocity in the runners must be slower than in the base tubes due to the difference in effective cross-section.

This cut went into the base 1.5" for a total hole length of 1.75" by 1" high. This provides a hole cross-section a little larger than that of a runner tube. The hope is that it will enhance top RPM breathing even further, with a target of a 6,000rpm shift point. With the 1"x1" opening it would flatten out around 5,700rpm.

I might add that I picked up a spare intake set for $100 to try this mod; so I still have my OEM intake in tact. However, now I am a believer; check out the dyno pull results on my site.

I did notice a slight increase (a few .01s of a sec.) in 60' time after the initial siamese cuts but the addition of the 2,000rpm TC more than compensated for the minor low end torque drop.



[Modified by 65Z01, 10:34 PM 3/12/2003]