projecthellraiser

I recently seen a front crossover build that had me interested in a manifold design that is super simple to build, but the design it's self is flawed due to the ability to overlap exhaust gasses into a similar cylinder.

Essentially it is taking 1.5" sch 10 stainless and building a tee manifold with it. So each cylinder will have a 1.68" outlet diameter but it is restricted due to them all merging into a tee that has the same diameter of 1.68" then stepped up to 2" pipe for the turbo.

My biggest concern is the overlap and how much it will hinder my amount of fuel/air I can get into the cylinder due to the diameter being so small for an outlet. I'm not looking to for god numbers but a decent 600 crank/hp would be sufficient. (This is going on a 5.7 iron block, 5.3 head, ls6 cam/intake t70 .96 ar turbo truck. I’m just not a fan of the log design. Don't get me wrong they work and are the norm but I want A/C and I want to explore a different route.

I know that this should spin the t70 .96 ar super fast due to the increased velocity but how much will that velocity actually hurt my goals?


Lastly how much power do you think these can support? I was thinking of making 2 of them and just stepping the pipe up to 2" and merging them at the turbo in the front corner of my truck. Or just making one and using a G body manifold on the driver side with a front crossover.

Thanks for your input,

Lance

pwrtrip75

iTrader: (8)

Of course they'd work....not efficient

Not sure what you mean by that....ive never seen anyone adding fuel through the exhaust side.

If factory truck manifolds or any other manifolds wouldnt fit your chassis.... they'd work... but i'd definately use these as a last resort.

Phil99vette

iTrader: (11)

Its all in your definition of work. My question is why would you put your time into that garbage?

projecthellraiser

I was refering to the the combustion chamber, and the overlap forcing exhaust gasses into another cylinder thus restricting the amount of Fuel/Air that can enter that Combustion Chamber.


I have looked at every factory manifold for the passanger head and to keep A/C and run my pipes how I want this seems the easiest way to do so. I can get away with a factory G body manifold or a truck with a V band on the driverside.

I only have approx. 16" of 2" pipe I will have to run to a merge collector.

pwrtrip75

iTrader: (8)

If you have the ability to make that... why dont you use 1.5" elbows coming out of the ports going into a 2" pipe, but angle all the elbows at a 45 degree so they are all flowing the same way? That would be more equal to a truck manifold... and way better flowing than what you have pictured.

87silverbullet

iTrader: (11)

People have used the c6 manifold for the passenger side to keep the A/C. Did you look into that?

FastKat

iTrader: (10)

The design has its limitations. Actually, it doesn't have a whole lot going for it. The shortcomings focus on how the exhaust gases will flow out of the cylinder, not so much how the fresh fuel/air will be pulled/pushed into the cylinder. Ideally, you want something that is going to separate the exhaust path from each cylinder until it can be merged into a single collector, using equal-length runners. This design does the opposite.

However, it's certainly not the end of the world, unless you're pushing for really really big numbers. The design looks practical and as you said, easy to build. If that's the best reasonable way to package your system into the space you have available, go for it.

I would not get hung up on the ID of the pipe. If you're that concerned about the compounded flow of the exhaust down the manifold as it reaches the 2" outlet, think about putting the wastegate on the opposite side of the 2" outlet, where you have the single 90* bend. Let's say the manifold does choke up right before the 2" outlet - if it does, it's most likely to choke up when you're pushing a high volume of exhaust gas through the manifold. That will also (roughly) be the time when your your wastegate will open. The open wastegate will help evenly distribute the gas pressure across the manifold by giving the exhaust an easier alternative to being pushed down the choking part of the manifold.

Blownz28man

iTrader: (2)

I'm sure it'd work, you may make some good numbers, but i'd try to make each on of those pipes merge a little better. Facing away from the exhaust port before it. If you think about it exhaust gases are just gonna come shooting out of the "T" hit the back side of your merge pipe and want to go against flow. Really don't know what that typed of manifold would do to hurt numbers, But if you still need to build might as well build a little more efficient. I'm having to build a log for my other side(passanger) just to keep a/c, but how I'm having the primarys merge i'd like to call it a "manifold" just cause a lot of people cringe when you say log manifold lol. Good luck!

projecthellraiser

Acutally I looked at doing that as well I have build the std. truck style manifold and all that really changes is the rear cylinder has (2) 90* bends and a step up to 2 or 2.5"

that is my other route. I have the material to built both no problem. I would like to see how they both perform.


I have looked at the c6 manifolds and well they aren't as clean looking of an install as say G body or truck manifolds.

I can fab a set of these up in under an hour, the log style well takes 3-4 times that.

projecthellraiser

I guess the biggest question is what kinda power would these support? 5-600hp? or start choking at a much lower level?

Everything you guys have said is what I had been thinking, I'm hoping someone that has ran a system like this would chime in and let me know what kinda problems he/she faced.

I know 4 cyc turbo honda and toyota engines do run something very similar to this just exiting the center as a mount rather then a passage. But they have the turbo mounted to the manifold and not 16" away.

gawath

projecthellraiser, I was actually contemplating a similar idea as yours. Yes, the exhaust will contaminate the combustion chamber of other cylinders due to the log design, but another factor that may need to be considered is the backpressure of the turbo being used.

pwrtrip75

iTrader: (8)

Run it and see. I dont think it wouldnt work. Not many people will probably chime in that have ran something like that because most dont. Test it and see how it works then post the results. On a small cubed motor 5-600hp it might work just fine.

kmracer

iTrader: (1)

its not that its not going to work, but flow is definitely going to be limited. thats actually the WORST log design, and a log design is already the worst as it is. if you're only looking for 500-600hp though, i wouldnt stress too much about it.

another thing, of you're going to run them, you're going to want to cut the flange to seperate each primary for expansion and contraction on heating/cooling.

kmracer

iTrader: (1)

uhhh... WUT?

98Z28CobraKiller

iTrader: (17)

Just cut and modify a truck manifold.

FastKat

iTrader: (10)

Agh... I meant to say wastegate, not BOV. I'll edit it.