Free flowbench testing

[AMMO]

I have a flowbench at work and have recently tested a Zetec head. I would like to test a K series head and a Vauxhall 16 valve head. Any of you with your engines in bits at this time of year who would like to have some data please feel free to contact me. This is to satisfy my own personal curiosity as at some stage the Crossflow lump is going to have to go.

 

AMMO

[gareth]

I have a QED head VX in pieces, it might be interesting

[gareth]

I have a QED head VX in pieces, it might be interesting

[AMMO]

Gareth, I was hoping for a stock head but that will do for starters. Where are you? If you want to call me you can do so on 01728 602101 days 01394 383499 evenings. If you want to come over the testing can be done while you are here so you can take the head back with you. I can also test the rest of the induction system, manifolds, throttle bodies etc. Ask for Ammo.

 

AMMO

[Peter Carmichael]

Dave Andrews has some flowbench figures for std and modified k-series on his website (here and follow the link to k-series tuning).

[AMMO]

Thanks Peter for the link. I've checked out Dave Andrew's site. Very interesting. Virtually everything you need to know about K series. Anyone know if there is similar information for Vauxhall?

 

AMMO

[Roger King]

I'm going to stick my oar in here and express an opinion that may not meet with everyone's agreement.

 

Whilst I fully agree that a flowbench is a useful tool for engine development, I feel that results must be looked at in the light of the real world situation.

 

When an engine is running, the valves are going up and down, there is a temperature gradient from ambient temperature to the combustion chamber and there is liquid introduced into the air (petrol). These and a host of other factors are really not reproduced on a flow bench.

 

Would you put a car in a wind tunnel, measure it's coefficient of drag and then say that you are going to drive along the road opening and shutting all the doors, but this will not affect the aerodynamic performance?

 

I well remember some years ago reading an article in a tuning magazine (can't remember which one) where the guy had flow tested his head and then announced that he now knew "that the engine will produce 143.5bhp provided that we use a reasonable sort of camshaft" - nuff said.

 

I also remember a customer who had two different heads flow tested, but the one that gave the slightly worse figures gave slightly more power.

 

Please don't interpret this as an attack on flow benches, but rather as a plea to use the results in conjunction with all other relevant factors.

[AMMO]

Roger, I agree with everything you say. I've had a flowbench for 12 years. It does not tell you everything. It is only another piece of the jigsaw puzzle that is engine building for performance use. It can give a pretty good indication of what BHP an engine is going to produce but some never reach their potential. Harley Davidsons spring to mind. It will tell you if a head is rubbish. The best MGB head I ever tested on the flowbench and that made the most horsepower on the dyno was done by a little old man in a shed who had never seen a flowbench in his life. You can do the job intuitively very well indeed. Most of the guys I know who build race-winning engines have a flowbench. Most of them agree that you have to view the results with a pinch of salt.

 

AMMO