The "X" port looks like an "IM" port.... a cheap one!

 

i have the 615-183

it's not a true A to B test since I put a lil baby cam in at the same time, but considering how much fuel I had to add in the midrange of the VE table I'd say it's worth the hassles to get it to run.

I am not really impressed with the coarse thread screws into plastic...and I had to use epoxy to keep it from developing a vacuum leak in the rear. But hey it's cheap and flows pretty good.

Would not consider it for a boosted application though.

 

Care to comment on just about everything else in the thread? The leaks, flexing of the "front/rear rails" causing leaks? Reason for the ramps in the intake runners where it meets the head?

 

How much did your Dorman weigh looks like 11 lbs ? What adhesive are you using to seal , name brand ?

 

the adhesive i used was epoxy, loctite hysol u-09lv. but anything rated for a polyamide (dupont's name for it is nylon---but you'll see PA66 somewhere on any polyamide part) will work.

on locktites website it appears a cyanoacrylic gets the best bond on PA's

scroll to page 36 in this pdf link

https://www.ellsworth.com/globalasse...ic-bonding.pdf

 

Thanks for the info , In your opinion do you think this adhesive will keep its bond, if the intake was to flex under stress or pressure ?

 

It's tooled that way in order to mold the port and runner shape. The edge is actually positive for flow.

We have a full team of Certified Technicians on staff at our HQ in PA. If you are having trouble with the manifold you can call them for help. 215-997-1800

 

Looks like a full-on dyno test is in order to compare an OEM LS6, unmodified Dorman LS6 , and a "modified" (port ramps ground off) Dorman LS6. Let's see if the "ramps" or "edges" as Dorman puts it, actually do it any favors.
Use a mild LS1 or LS6 to recreate a typical situation.

 

[QUOTE=G Atsma;19624477]Looks like a full-on dyno test is in order to compare an OEM LS6, unmodified Dorman LS6 , and a "modified" (port ramps ground off) Dorman LS6. Let's see if the "ramps" or "edges" as Dorman puts it, actually do it any favors.
Use a mild LS1 or LS6 to recreate a typical situation.[/QUO

Its important to note that Dorman develops these Intake Manifolds as OEM replacement parts - not performance. Any modification that customers do after purchase to alter the flow of the manifold is on them.

 

Are you saying you sealed it to prevent a vacuum leak, or that it actually did develop a leak? It sounds like you just assumed that it would leak and sealed it anyway for insurance but just wanted to clarify.


Thanks for clearing that up. Can you say whether Dorman and Super Auto intakes are manufactured by the same company?



From Dorman's 10-K SEC filing:

Manufacturing
Substantially all of our products are manufactured by third parties. Because numerous manufacturers are available to manufacture our products, we are not dependent upon the services of any one manufacturer or any small group of them. No one manufacturer supplies more than 10% of our products. In fiscal 2016, as a percentage of our total dollar volume of purchases, approximately 23% of our products were purchased from various suppliers throughout the United States and the balance of our products were purchased directly from vendors in a variety of foreign countries.

And let's not forget the 16,000 sq. ft. Dorman office in Shanghai, China. Now, this intake should be made in the USA according to the Dorman website but probably not by Dorman.

 

Understood. My point was to see whether or not the ramps actually contribute flow or power, or if grinding them off actually degrades performance.
If a slight modification can reap benefits without compromising the structural integrity of the part, then so be it, even if the warranty is voided.

 

Again….. Dorman and SuperAuto are not the same manifolds. Not the same company. Not manufactured in the same plant. Do not use the same tools or drawings and never have in the history of Dorman since 1918. Dorman, like any many companies sources products all over the globe. This Intake is Made in the USA and always has been since its release. And yes Dorman owns the tooling. Although I can’t recommend - If you prefer the China made one – feel free to purchase the SuperAuto.

 

Well put!!

 

yeah the epoxy has some flex to it. not sure about CA glue.


nah it was leaking. verifiable in the old school manner with carb cleaner.

I would not use it in a boosted application.

 

Both are piles of **** in build quality so yeah you are good either way. Sad to think that most of the "U.S.A." built items are so poor in quality. Loss of pride, sad. Work in this field everyday for the last 20 years and it is terrible to see the way it is going.

 

Somehow I don't believe an intrusion in the runner is a positive for flow. Let's look at it this way, the dorman has the wedges in the intake runner, stock does not, secondly the wedge is the same principle as the stock LS heads that have the swirl ramp casted into the intake runner right inline with the valve guide. Dorman has effectively added another swirl ramp before that into the runner. The swirl ramp in the stock head is NOT a performance option, it promotes low end efficiency by adding turbulence into the air stream right before the fuel gets squirted which helps atomize and mix the fuel in the air (a lot like a carb Venturi). This swirl ramp while it helps with emissions and efficiency at lower Rpms it is actually a hinderance at medium to higher Rpms where efficiency isn't tested. It's a fact that most high end big name company race porting shops will grind the stock swirl ramps out of the head to improve mid to high rpm flow. Not to mention most of the newer LS3+ don't have the swirl ramps casted into the heads anymore. So GM must think they aren't needed anymore or affected performance negatively. I for one removed my swirl ramps in my stock heads when I ported them and put them on my motor. So please explain how swirling the incoming air right before it gets swirled again is a positive for performance. It honestly seems like a reduction in intake runner cross section causing a depression in flow velocity. Think about a bottle neck that opens again after and then necks down, flow increases to the bottle neck then slows down as the are after opens up and then has to speed up. Air looses all its velocity and speed and this happens when people port there heads wrong causing a reduction in air velocity into the chamber.

Now what I think dorman did here was add this ramp to the port to add a restriction so it doesn't fully copy the fast 90 base. Dorman owns the rights to the fast base mold but probably can't copy it fully. Not to mention degrading its performance makes it a stock replacement more than a performance replacement. So dorman makes a large plenum long runner intake that shares nothing with a stock truck intake, looks identical almost externally to a fast truck intake and uses a copy of the fast base but adds the ramp restriction to the base. Now for reasons stated before dorman did this to cover there *** per say but more importantly if you fix what they did on purpose you could have a solid intake. Remove the performance robbing second swirl ramp and see what you get. I'm sure most of us will be surprised.

Dorman, nice try!

I will be gluing mine together like truck Doug and then boosting it to 10psi over my stock intake. However I won't be getting it Dyno tested unless someone wants to pay for it. Otherwise I'm happy to share my logs and injector duty cycles with the forum after I do the swap. You can calculate hp via rpm, cuin, fuel flow etc.

 

If that method is accurate (I suspect it is) then why does anyone Dyno their LS vehicle? I get that RWHP will be different but horsepower is all relative anyway, so I think that rwhp is unimportant when comparing performance.

 

My dorman intake did the same thing when torqued down, evident from blow by/pcv oils seeping from between the intake halves. No "apparent" vac leaks.

 

My Dorman LS2 intake looked to be fairly good quality. Also pretty much looks like stock for the sleeper look and they are a PA based company who makes stuff in the USA. Not too shabby for the price.

 

The dl2 is sonic welded together. The truck intakes arent. They use a FAST style rope seal and a few screws.