Inliners International Forums General Discussion Blown and Injected intake port dividers (prototype)

Here is a couple pics of the newer divider. The engine runs much better.
Better starting
better idling
better acceleration
Less fuel needed.

Interesting.
Are you going to dyno or track test it to see the improvements?

See where the torque peak is max HP RPM etc?

No more lumps?

MBHD

Hank,
This head was installed last year in May 2010. I documented it in my 292 turbo writeup. Just posted this here to help keep the data in one place.
Short story. Last year took it to the track and ran it. It performed the same but had power loss. Found out days later the distributor was the problem. So no proven track times.

No lumps because of the turbo and the smaller port window. It does make more power but no dyno close by or time to do it.

The storm that hit me this year was a summer wrecker. Missed out on a week of vacation to cleanup the mess and rebuild my blown down building (just like it was done by the big bad wolf to the piggies). New building is up but much to do to get ready for winter.

Tom, I don't know what I'm looking at in the second picture.

Tom,
Are you planning to sell the divider or is it so custom that wouldn't be possible?

As a pro-lurker here due to my work's firewall preventing me from leaving posts, I just want to say thanks Tom for posting up pictures and updates on the EFI turbo projects. I keep watch as I start working on my turbo'd EFI Pontiac OHC six.

That sounds like a pretty cool and unique project, make sure you give us some pics and updates more often.

Beater,
The second pic is my intake manifold after I matched it to the new head port.

Copo Rat,
Yes those same type dividers can be done, but the head has to come here. Too much fitting.

Silver Buick,
Thanks for the pat on the back. Just trying to keep good info out there for other people to use. Today recieved a phone call. Guy has a 292 that is turboed and making way too much boost. He wants 5-7 and is seeing 14 psi by 4K rpm. He is getting scared of hurting it. We discussed his whole motor and I gave him some ideas on how to calm it down. Ultimately ,I think his turbo has too small of a exhaust housing for his exhaust wheel. He has a Garret 3788 with a .89 exh housing. Just trying to tell him from my experience.

Glad to see you are giving advise.

So Tom,
from your experience, you have used a larger .99A/R, or 1.11 A/R on your 292? If so, how did it work out w/your converter? What RPM did your 292 see full boost w/the .99 A/R or the 1.11? Or better yet, what RPM did your 292 begin seeing boost?

I am interested in your findings.

I believe those are the next 2 sizes available for him to use.

IIRC, off the top of my head, you were using a .68 A/R initially on your 292 & now you currently have a .84A/R ?

MBHD

Never used a housing that big on mine. You are right , have a .84 currently.
His is making too much boost and thats why he called me. I did not sell him his parts , but am trying to help him figure it out.

Yes , when I looked up his turbo, those are the next sizes. They seem to only offer 1 exh wheel. I am used to Turbonetics, they offer different wheels and housings.

What do you think his problem is?
He has timing pulled out with boost
A working wastegate
builds boost quickly
using a blow thru carb setup
water/ alc injection
This stuff is only going to detract from the original post.

It's hard to say what is wrong w/not knowing his layout on the plumbing,what controls the wastegate, parts used etc. & just by talking to the guy on the phone.

"The GT3788R is perfect for 2.0L - 5.0L engines looking to make 440 - 675 HP. Twin scroll T4 turbine housing makes for quick spool up." Taken from a website.

Maybe he could join here & post some pics?

I believe he has the devided/Twin scroll T4 turbine inlet?
If so, he could use the open type, not devided T4 turbine housing.
That should slow it down a bit.
We need to see some pics, maybe some data logs.

MBHD

Turbo too big for only 7 psi it's at the bottom of the efficiency islands. Best suited for 15 psi plus.
What size wastegate ?
What wastegate control ?

Should start a new post.

Harry

Copo-rat,

Dividers are easy to make just cut a cardboard template that fits the port and cut out a piece of steel held in by a bolt or tapered plug in the top of the bolt boss, I have been dividing ports since about 1965, used cast iron crank counter weights furnace brazed in to use the stock bolt, cut steel flat plates bolted in, cast steel wing shaped dividers that bolt in, the same cast wing that goes behind the stock boss that is tacked welded and epoxied in place, all work just fine.

Tom, Very innovative idea of opening the top of the port, have you tried to see what the flow is, how thick do you think the port is afterwards, you should sonic test it. How wide is it at the top now that it's ported ?

Harry

Post number 41801

"Best thing to do is widen & raise the roof of the intake ports."

I did this many years ago that is why I suggested doing it.

The casting is still plenty thick.

I even ported my intake openings more than Tlows.

MBHD

Hank, How do I find this post (41801) do you have pictures?
How do you raise the roof there is not much area to seal now?

Harry

Harry, heres a typical brazed lump port showing how high and wide the ports are generally opened up. This port shown here is a commonly sized intake port with dimensions of 2.540"L x 1.625"H and theres is no telling how many dozens if not hundreds were done this way by Headrick, Sissell and Self and yielded outstanding results.

CNC,
That's a normal lump port, I had one from Kay years ago,but Tom's has the port opened up way more at the top and I did not know there was that much meat to do that safely. I have an old junk head I am going to cut up and see what's there in thickness.

I feel with a Turbo and divided port you need volume more than shape, yes-no ?

I'm just trying to see how much HP I can get from a stock divided head on gas, before switching to a Kirby 12 port.

At about 760 HP now hopeing for more.

Harry

Harry,

I did not take any pics of the intake port after I devided it & raised & widened the port.

You are correct about not much sealing area after opening it up this much.

If you really want to see what a stock head can do w/a turbo & deviders installed.
You would really need to braze the top of the port.
Raise the roof as much as possible & widen the port.

With a turbo & devided port, you should not be so concerned w/intake port volume, you need to concentrate more on how big you can make the intake port window.

Having a better short turn radius helps, but if you are looking to make a lot more power w/your turbo & deviders, focus on the
smallest area of the intake port (basically @ the mating surface area on the cyl head to your intake manifold)

IMO, we do not have a lot of options when it comes to having a good flowing cyl head when running deviders also. Those two things usually does not go hand in hand.

Thankfully you have a turbo that will force the air/fuel into the cylinder head even w/the deviders & having horible flow numbers because the the devider & no lumps.

I was always concerned with intake port velocity when being naturally aspirated, need decent port velocity to make any type of bottom end torque.
But when you are forced induction, worrying about port velocity is not a concern, throw that type of thinking out the window.

Just make the smallest portion of you intake port as big as possible w/out going too crazy (less reliable, sealing issues etc)

I believe you can make more power this way than if you are running a small port w/deviders & lumps. (only forced induction I'm saying)
MBHD

I can send you some photo's of the heads side profile if you want them.Larger then what is on my web site.

So kind of bringing this up from the grave

But Tom
1. Are you still running your deviders
2. How are you holding them in and how is it working?

I have mine made just no idea how to keep them in well I have and idea just would line to know how you were doing it

Or anyone else for that matter it's the last step before wiring on my turboed 292 and custome intake and fuel injection

Thanks,
Josh

Happy inlinning

Josh, there are many ways to do it, and all of them good and acceptable. I saw it done 20 years ago on one of our customers race engines, he simply tack welded them to the end of the intake flanges as an extension that basically inserted into the ports when he bolted the intake on. You could also make a thin spacer to go between the head and intake with them welded to it. Downside may be having to use longer bolts and a spacer on the header flange also, but they stay in place when you remove the intake. You can even use the short head bolt hex cutout as a bottom support and the pipe plug that fills the upper part of the head bolt hole to capture the divider also. Many ways to get there and all are pretty easy. Just pick what suits you the best.

Josh,
Here is how mine are made. First of all, they were made by a fellow inliner and installed by him. He is local to me. At the time there was a bunch of work being done with the dyno engines and he offered to help out.
There is a special plug that has a thru bolt to thread into a nut welded into the divider. The divider sandwiches the head with the bolt and plug.
The engine ran much better once the lumps were put in. Smoother idle and cleaner acceleration.
Notice the lack of lumps and the enlargement of the port. The intake manifold also had to be opened up to match.

Would it be too restricting for a turboed application to not open the port that much?

Very clever idea! How did you seal those on the head?

Not really for a street engine. Im helping a local LS racer that competes in the drag radial class in NMCA and is making close to 1500 HP with heads that are not even ported very aggresively at only 300 CFM. Don't get sucked into the "how much does it flow" hype, its only part of the equation. But I would try to regain the area taken up by the width of the divider in each port. Forced induction is a great compensator and equalizer in making an engine that can't into one that can.LOL

Excellent that makes me feel better about it