Time to go Stage II!

[Alky V6]

When working with tunned runners, I would think that you would need to double or tripple the length to get you back to the same optimum fequency. 1 inch may start dropping power but there should be a point where it starts to pick up again ??

Allan G.

There is a very marked gain at 2.0". At 3.0" there is a dramatic drop. About 15 hp per cylinder at the peak values (6% power loss). From 3.0 to 4.0", another drop, but not as drastic. Above 4.0", with each additional inch there are more drops, but comparatively minor compared to the 2 through 4 inches range. I've looked at lengths to 7.0 inches. I really don't want to go any longer than that.
The pattern shows that with additional runner length the top end drops and the low to midrange gains. The teeter point is around 7,300 rpm. I only plan to be under 7,300 rpm for a split second during the launch, so I'm not really concerned with low to midrange torque.
If you study high rpm engines, you will notice that short runners are the order.
Blower intakes are the same way. Short runners. Blowers supply their own torque, so tuning in long runners to pump up the low to mid-range is not necessary.
In my case, nitrous will be used to pump up the low to midrange, and get the turbo spooling, so sacrificing top end performance with longer intake runners will not be necessary.

 

[Alky V6]

The ports in the flanges are finished. Starting to trim it up.

 

[geno]

How do you get 15,000 views because your changing heads? I had 25,000 building a car over 5 years?

 

[Alky V6]

How do you get 15,000 views because your changing heads? I had 25,000 building a car over 5 years?

lol Beats me.

 

[750H.P.V6]

How do you get 15,000 views because your changing heads? I had 25,000 building a car over 5 years?

It's the dyno graphs. Guy's on internet car forums LOVE dyno graphs.

Neal

 

[Alky V6]

I think it's that people just want to see what the crazy person's going to do next.

With the short intake runners, most of the intake mounting bolts will be trapped by the plenum. I was originally planning to have the fasteners that will hold the intake runners to the flanges going in from the gasket side of the flanges, like the Stage I manifold. Another option would be to have the runners and plenum fastened to the flanges from the top. The intake would essentially be assembled onto the engine. This would mean a lot of bolts inside the plenum. Safety wire time.
Any fastener heads in the plenum will need to be far enough away from the runner entrances to not interfere with smooth airflow into the runners. With the room that will be available with the Stage II layout, that shouldn't be a problem.

 

[Alky V6]

Next question. Is 5/8" enough room to mount the E injectors and the nitrous nozzles? The nitrous nozzles may have to be internal, like turbobitt suggested.
One thing is for sure. This intake is going to be very unique.

 

[Alky V6]

Pretty much done trimming the fat off of the flanges. I'll wait until the intake is further along before I decide if there's anymore material that needs to be trimmed off.

 

[Alky V6]

At this point, I should add something. A warning.

Warning! If you are the type of person who is easily offended by BUICK porn, please continue no further into this thread.

I did some calculating and I decided I can take the length of the intake runners out to no longer than 2.8". This should give me the needed room to mount at least the two E injectors per runner.

 

[norbs]

Question, does the AL block require special head studs for S2 heads?

 

[turbobitt]

At this point, I should add something. A warning.

Warning! If you are the type of person who is easily offended by BUICK porn, please continue no further into this thread.

View attachment 162465

I did some calculating and I decided I can take the length of the intake runners out to no longer than 2.8". This should give me the needed room to mount at least the two E injectors per runner.

Cooling passages ??
Allan G.

 

[norbs]

Speaking of cooling passages should I bridge the rear two passsages together at the back of the intake with a hose?

 

[Alky V6]

Question, does the AL block require special head studs for S2 heads?

I have an ARP stud set for the Stage II heads. I've already fitted them and they seem to be fine with the TA block. I have to add that the head bolt holes in the deck of my block have all been helicoiled (long inserts). I did that early on in the Stage I development. After a few times of torqueing honing plates and heads back and forth onto the block, the threads weaken and begin to give out. The helicoiled holes have a much higher strength than the threaded aluminum holes. I strongly suggest to anyone running the aluminum block that you helicoil the holes early on, instead of waiting for them to begin failing on you. It is a very precise operation. Don't go just guiding a drill motor by hand.
Also, countersink the inserts into the holes

 

[Alky V6]

Cooling passages ??
Allan G.

The cooling passages in the intake will be dealt with the same way I did with the Stage I project.
You want to make sure any trapped air pockets have a way to circulate out. I run a -4 line from the back of each bank to the front of the block. As the line passes the front of the block, I 'T' into the line at the front coolant passage. After that, the lines from each bank will turn towards each other and join. In the middle of that joining line will be a 'T' off line that will 'T' into the radiator hose near the entrance to the radiator.
I haven't added the coolant passages in the intake flanges yet because I want to see how the runners are going to develop before I pick the spots to add the coolant fittings.
I should add that the major coolant flow back to the radiator will be handled at the front ends of the heads, where there are provisions. Just like I did with the Stage I project. The small -4 lines at the intake flanges will generally be there to simply provide bleed flow to carry air pockets out of the heads.

 

[Alky V6]

I've been thinking about the runners and the plenum. Some ideas that popped into my head. A lot of plenums have a large plate that bolts to the top of the plenum. Why not have plates that bolt onto the sides of the plenum? The back? All surfaces? Since this will be a bolt together manifold, am I restricted to just aluminum? Would a stainless plenum resist picking up engine bay heat better?

 

[Alky V6]

Speaking of cooling passages should I bridge the rear two passsages together at the back of the intake with a hose?

I think I answered your question in my reply to turbobitt. You don't want to trap any air pockets. You want to circulate them out.

 

[turbobitt]

I've been thinking about the runners and the plenum. Some ideas that popped into my head. A lot of plenums have a large plate that bolts to the top of the plenum. Why not have plates that bolt onto the sides of the plenum? The back? All surfaces? Since this will be a bolt together manifold, am I restricted to just aluminum? Would a stainless plenum resist picking up engine bay heat better?

Does it matter with Alky ? How about a plenum with plastic insulators between runners and plenum ? Maybe Delrin or something.

Allan G.

 

[turbobitt]

I think I answered your question in my reply to turbobitt. You don't want to trap any air pockets. You want to circulate them out.

Not to dispute the connecting hose but what would it actually do ? Think about it.... In theory, you would just be giving the air a higher place to sit. Unless you get a little more creative and connect a small bleed to the front to allow flow. Maybe a manifold to collect water from all four corners of the heads would be better ? Maybe a manifold sitting on the bottom of the valley plate would be trick. This would make it eaiser to capture water from all four corners.

 

[Alky V6]

Does it matter with Alky ? How about a plenum with plastic insulators between runners and plenum ? Maybe Delrin or something.

Allan G.

You're right. With alcohol it wouldn't really be a concern. I like the Delrin idea. Fun stuff to work with. But, it will melt if there is a fire in the intake, started by a backfire.

 

[Alky V6]

Not to dispute the connecting hose but what would it actually do ? Think about it.... In theory, you would just be giving the air a higher place to sit. Unless you get a little more creative and connect a small bleed to the front to allow flow. Maybe a manifold to collect water from all four corners of the heads would be better ? Maybe a manifold sitting on the bottom of the valley plate would be trick. This would make it eaiser to capture water from all four corners.

If the cooling system is setup correctly, you should have more pressure in the block than in the return hose to the radiator. A thermostat could be the restriction that sets up the pressure differential, or an orifice placed at the beginning of the water return hose to the radiator. I use hose size to create enough restriction to cause a higher pressure in the block than in the return hose just up to the entry to the radiator. It's at that point that I have the bleed hose tee'd into the return hose.