VK45 Head flowbench

[marksport]

I had a factory and a ported VK45 head flowbenched

Stock head:















Ported Head:













































Both heads:





Results:

[Q45tech]

Interesting that the PORTED HEAD lost low lift intake flow [in 0.1>0.2] so the Ported Head might actually make LESS power than the stock oem.

What were the reversion flows [measuring head backwards] a very important parameter during overlap period.

On exhaust not sure how much the >0.2 lift increase gains you since the intake flows are probably worse.

What were the numbers for each cylinder?

[maxnix]

I don't know anything about porting othere than it is meant to increase air flow.

But could you explain the aluminum bits around the stem? Looks rather scary to my ignorant eyes.

Anyone like Q45tech know what the flow numbers for the VH45DE are?

I thought the VK had infinitely variable exhaust also?

Thanks for the post.

[gs14racer]

Who did the porting for you? The exhaust gained a good bit of cfm but the intake did not? Even polishing the ports increases cfm a bit.

[Carl H]

looks like if anything a quick cleanup of the exhaust ports is the only thing needed to optimize numbers...sucks that the ported intake head lost flow.

[Johnny Rocket]

Interesting that the PORTED HEAD lost low lift intake flow [in 0.1>0.2] so the Ported Head might actually make LESS power than the stock oem.

What were the reversion flows [measuring head backwards] a very important parameter during overlap period. Waste of time

On exhaust not sure how much the >0.2 lift increase gains you since the intake flows are probably worse.

Any pick up ont he exhaust side of the engine is a big deal...Thats a nice intake to exhaust ratio 77% Years ago they shot for 70% but now its all you can get without losing port velocity... 80% is real good and will show an increase in power with a free flowing exhaust.What were the numbers for each cylinder?

The head is symetrical....so why would you worry about the rest of the cylinders....? They are all going to be very close...

[Johnny Rocket]

4 valve engines are a different breed when it comes to head porting...I have done a few sets on my 4 valve trailblazer engine...I would like to see the head flow with more lift...They dont want much lift but this engine could use some more..the head you ported should flow more with a higher lift of the valve..more window

The exhast is a nice improvment.......not to be taken lightly...

The intake might be better up higher.......can you get them flowed with another .100 of lift?

I have been using the flow bench since superflow first came out with them in about 1980 and they have were real misleading at first.....especially on the exhaust side of things....

Every time we got the exhaust better we picked up power..

.

[Johnny Rocket]

You only had 67% percent of the Intake before......now you have 77%..thats huge!

[XJared]

I would like to see a VK56 compared as well if anyone has one laying around. It looks like the VK56 ports are actually bigger, but it looks like the runners are longer.

[Protune Racing]

Any chance you got some velocity figures aswell?

James