How many CFM can we flow?

[Zuffen]

I found some interesting figures on the capacity of the 1UZ-FE cylinder head to flow air.

An article in an old Auto Speed described how Flow Testing is done and why. Interestingly they chose a 1UZ-FE cylinder head to use as an example of before and after flow figures.

According to the article the following flows were obtained using a standard unmodified head. All figures are in cubic feet per minute (CFM).

(Sorry the below table doesn't display too well the spacing goes whacky when I submit the thread. I hope you follow what's happening)

Lift (in thou of an inch) Intake exhaust Increase
50 24.2 18.4
100 51 36.3 97.28%
150 77.1 57.2 57.60%
200 96 66.4 16.08%
250 113 74.1 11.16%
300 121 81.7 10.26%
350 124 86.9 6.36%

Intersetingly the law of diminishing returns has kicked in at 300thou. Increasing lift to 400thou shouldn't give any more than 4% increase which isn't much given the additional strain on the valve train and the fact the engine may encounter interference.

Following some port work the head flowed 147 on the intake and 94 on the exhaust. The article doesn’t say at what lift the “after” flow was measured at but a photograph of the head shows the figures were compared to the unported 350thou figures. The photo shows the head with the four figures written on adjacent cylinders.

This suggests the porting gained 18.5% on the inlet and 10.8% on the exhaust. Pity the exhaust didn’t gain a bit more.

I would think 18% on the inlet and 10% on the exhaust side combined with a decent set of headers and a well thought out exhaust (JBrady style) should deliver a fairly substantial increase in HP. Last time I checked the cost of porting was around Aussie $1,200.00.

Has anyone done any back to back dyno runs without/with porting? Or has anyone done any flow testing to see what is happening or what we can gain.

 

[Lextreme II]

Graph on the flow rate www.lextreme.com/lift.html

 

[Muzza_NZ]

Lextreme,
Shouldn't that 97.28% on 100thou lift on your linked table?

 

[cribbj]

Interesting figures. By way of comparison, attached is a jpg of what a Supra head flows, before & after porting. Note the flows were done at a pressure of 28" wc. Flow figures are meaningless unless the pressure is stated, or unless relative flows for the same head are being compared, but even then, the pressure has to be held constant.

In another thread, David was curious why so much power can be found in the 3.0 litre 2JZ-GTE motor. This may be one of its secrets. Engine builders always say that more power can be found in the head of a motor than anywhere else.

John

 

[Lextreme II]

Possible typo from my link. I just copy from Rod and try to make something out of it. Nice graph!... thanks for that. Can you make a graph for the 1UZ also?

 

[MaxPower]

I was speaking to someone today about their twin turbo 1UZ and where the development was at with it. He was saying they will be getting a set of billet heads done up in about 6-12 months time as they have reached the limit for a set of stock castings (heavily ported), the car is making well over 1000hp to do this though.

If anyone is serious about this - it would be cheaper with a few people - then i can pass u on some details (they are in Perth). I dont know the cost, but if u need to ask then i dont think you could afford it, lol.

 

[Zuffen]

Max.

I think that's a quote from a Rolls Royce Slesman.

The story goes that if you need to ask what it costs to maintain a Roller (and it's plenty!) you can't afford the car.

 

[MaxPower]

hahaha, yeah and these heads will prob cost as much as a roller too!!

 

[quadcam boat]

Anyone read Zoom edition no. 78? (pages 38 -42)
The 1uz powered Camira is putting out 783kw at the flywheel (twin turboed as you would expect!)
These guys claim the heads havent been touched! It does have reground inlet cams though. I would expect upgraded valve springs as well!
If you were setting up an engine of this calibre, how could you not resist a bit of headwork? It has aftermarket rods and pistons, so the whole engine has been disassembled, the perfect time to get the die grinder in?
Anyway if this the heads haven't been touched as claimed, thats a pretty impressive endorsement for the standard heads!
It's in W.A., I wonder if these are the guys looking to make the billet heads??

 

[MaxPower]

the heads have been touched - and i think u may be onto who is having the heads made :wink: They are building a new car and a more powerful engine combo.

 

[Zuffen]

I think you'll find the billet heads won't have all the water passages in them as it would be a massive task to mill the passages under the dome of the combustion cnamber.

As it's used on a dragster the lack of cooling won't worry them too much.

Top fuelers don't have any water passages in their blocks or heads.

 

[MaxPower]

Zuffen - yes thats correct, i figured it would be pressumed that would be the case, just the cost of having a set made makes them prohibitive for street applications. The 1UZ that will be using them runs methanol hence no need for a cooling system - any drag car that runs regular fuels (such as the VP range of race fuels) will require a cooling system.

 

[techo]

Lexus Head Flow Rates

I personally have seen the heads on that Blown Lexus Altered Darg car and know for a fact they have gone 200 PLUS CFM. Speend costs, how fast do you want to go! I am having my heads ported by Go Mac and they will be better again than the previous motor.

 

[Zuffen]

Techo,

Could you tell us more? Such as what it will cost and what it will/does flow.

Maybe a new thread specifically on porting wouldn't go astray.

 

[Lambo]

Porting

Hey Zuffen, that sounds like a good idea, the knowledge will be with someone out there, i have read a little about it but the thought of attacking my 1uz heads with a die grinder, when i have not a clue how is not on my "lets do it today list" , someone must know what to do or not!!!! or is it another automotive black art, like when you take your transmission for service and get a $2000 bill

Regards
Lambo

 

[cribbj]

Yeah, it's a black art all right, and an expensive one. The 2JZ head whose graph I posted earlier has about $2500 USD of porting in it.

Good head porters are a real independent lot; they name their prices and get it, and they work to their own schedules. Some will just tell you to come get your work if you try to push them. They don't need your business and don't want the aggravation.

It's "real" easy to cobble up an aluminum head with a die grinder, so most people bite the bullet, kiss butt, and pay the price to have it done.

John

 

[turboteener]

Somebody is doing something wrong or shouldn't be driving a die grinder. My SOHC honda head with a mild turbo biased port job flowed 276 and 214 @.500. Flowed at 28 inches. These heads appear to be better than those. Since I haven't had the heads in hand yet, I can only make observations based on pictures and looking at the heads on my engine.

There appears to be severe shrouding around the valves in the chamber. Also looks like there are good gains to be found in the bowls. I haven't figured out why Toyota did this Mickey mouse offset port on the intakes. Some swirl could be created but they could have done the same with camshaft profile.

I don't know why you would bother with Billet heads. Why not just weld up the stock heads to create the profile you want, then you don't lose the coolant passages and it would be significantly cheaper.

Any idea what the blown drag guys are running for heads?

 

[EyesofThunder]

Any idea what engine this was done on? I am looking for intake/exhaust flow data on the 1UZ-FS VVTi heads. I have a model in Desktop Dyno I am working on. With what I have so far it isn't far off at all, but right now torque peak is a little low and a little high rpm.

Graph on the flow rate www.lextreme.com/lift.html