Thread: Time to dispel some of the crap

I wasn't going to do this post. But thought it will benefit the community.

Rumor 1

hard to get over 200whp due to poor intake velocity

Rumor 2

head work has no gain on a ve

Now instead of using examples like;

"my fully sik cuz hacked his ve ports with a dremel and didn't get any gains" or

"Mate got some head work, just cleaned up the dribs and drabs but didn't gain anything"
or

"I heard of an interweb gangster who made wicked sick power on a stock head so head work is not needed."

I will simply post pics. and discuss.

Ok first intake velocity rumor.

First of all some good head work proper speced to fuel used and rpm that the engine is to make peek power with a good 5 angle valve grind will pick up both flow and velocity on a ve head.

Second the ve head does not have bad intake velocity! Yep i said it. The intake velocity SUITS a high revving 4 cyl motor. If intake gas velocity gets too high it can cause the motor chokes at high rpm this results in potential power gains not being achieved. So when reving to 9000rpm having lowish intake velocity can GAIN power not restrict it.

Third yes there is a restriction in the standard head but it is NOT intake velocity.


Ok next rumor head work gains. Well i will post pics of before and after on one of our na heads And you decide for your self.

This head is speced to make peak power at 8000rpm but still be very close to max efficiency at 9000rpm. It will also be running e85 so we have been very conservative on the ex, we may take out a little more later on with some more testing as the head is 90%done, but good enough to use as an example.

The standard intake has a good basic shape, however it is quite compromised by rough factory castings and bad core shift. Here is a pic.



As a comparison here is what it looks like now



Here is a pic of the factory intake short turn. Note the core shift. Not all are this bad on the intake.



and after a play



Now i mentioned the restriction in the ve head. A ve compared to a de uses 1mm undersized valves. This is not the restriction, in fact for an na motor its a good thing. However what is a restriction is that the chamber is far too small for this undersized valve, The port is rough as guts and the short turn is just HORRID! There is no way even on a na motor that ex will keep up with the intake at high rpm. Definatly not with that short turn creating all types of turbulences as air exits the combustion chamber. It can be slightly masked with e85 or meth but will NEVER be ideal.



our conservative job. remember this head will be running e85.



The horrible short turn. Also what you can't see in these pics, is just how rough it is with all the weird shapes causing problems behind there.



our job. Still not 100% finished, but pics shouldn't show up whats left. You can clearly see the huge difference at this stage though.



and some pics of the standard chamber vs ours






As you can see there are huge gains to be made on the stock head. Intake manifold (this will need to be addressed with head work), good header and some head work not performed by a monkey will see very good gains on a ve.

RUMOR # 1 IS FALSE and it can be proven on stock head.

^^^Yes indeed it is. And yes it certainly can. you read the post right? not just read the rumors and looked at the pics?

yes i did and with that flow of the head itll get you on a right set up 220 to 230... depending on what compression your goin for ..
n1 cams and cam gears with dyno time it should squeeze out alot.

youll need a asp header for good compresson that ssac sh1t isnt gonna cut it

price tag on that level of work would be cool also... looking great so far!

so what would you do to a stock intake manifold? we have a number of examples of good hp gains with an upgraded intake manifold... how could i get those good numbers with a ported stock manifold somewhere in the region of 5-10whp w/n1's, 4-1, 3", ECU?
because that basic bolton package doesnt usually put us over 200whp, or just barely does... i think most here would be satisfied with a 215-225whp with boltons, and we all believe an IM is a part of the requirements (w/stock compression).

Price of this kind of work will be more than most on this forum can afford. The purpose of this thread was not to advertise but rather give some insight into the ve engine. Point out that the intake velocity is not the problem in fact it is quite good for a high reving engine and that it is the ex that cant keep up at high revs.

If people are serious on getting some headwork done email me or pm me and we can talk as we always spec a head to the goals of the motor. So prices can vary.

We are currently doing flow test work with some intake manifold set ups. Problem with standard intake manifold is that although it flows ok, when bolted to the head it causes the head to flow a lot less. This is not uncommon, happens on many engines, but when doing an aftermarket im you really have to flow it with the head. Cant just get an intake manifold, flow it then go yay it flows more than my head, perfect ill bolt it up to the engine in my car.

But as a basic guide to mod your standard manifold match the upper runner to lower runner (these are often quite far out) and get rid of as much reverse taper as possible. Take about an inch of the runners and possibly and extrude hone. Problem then is after you do all that work to a standard manifold you are getting up near the cost of a custom unit.

Nice pic work.

The short turns are definately where the money is to be had with these motors. Im current performing the same work to my VE head, and found the same issues shift and casting wise.

The N1 head was cleaned up like this before assembly, and this is why the N1 intake manfiold was used to suit it. Which is also why many people dont gain using an N1 intake manfiold on the standard VE head.

The factory VE intake manfifold sufeers really badly from poor casting - its alignment is horrible, but the runners arent so bad. Ive simply matched all the runners between castings up 100% and the difference is potentially huge on a light setup. I beleive from just playing with headwork and the intake manfiold your average joe can easily see 10-15 peak WHP.

One thing that has concerned me on the VE head is the chamber depth and design. Im not a fan for it for knock resistance especially on higher CR, i guess this might be why your using E generation fuel in the setup you are playing with.

the n1's also run a smaller ex valve with a different neck which suits the ex ports a little better. The deshrouding of the valves on the n1 also helps with low lift flow. low lift flow of an n1 head vs 20ve is night and day.

yeah easy 10-15whp But that wont be the only gain....powerband will be sooo much better. Depending on how hoe the head is speced you should see either huge top end gains or more power EVERYWHERE!

Awaiting post on exhaust ports...LOL

After you mentioned the exhaust ports in another thread, I checked mine out while the head was off. WOW! Intake (for being stock) seems pretty smooth, exhaust on the other hand...YIKES!

Very nice work, but beside all the pretty pictures do you have any concrete numbers to back up your opinion on the port velocity.

What kind of speed are you seeing with the pilot probe?

What's the cfm before and after porting?

Any dyno numbers?

Remember the low intake velocity idea was based on most of the VEs making peak power around 7,500. Of course the port velocity will be higher if you spin it up to 9,000. What was too slow for 7,500 is now too fast for 9,000.



I would also like HKS Danny to chime on this. His answers are always interesting.