Jump to content
Click here if you are having website access problems ×

K-series DIY head porting


Albert Donaldson

Recommended Posts

Good morning All,

After reading dva web page and being smitten by the lure of extra power I went ahead and purchased and fitted a K04 kit to my EU3 1600(1320 cams) +forged pistons. At the moment its running wideband in adaptive mode and I am pleased with the results so far, but am looking for a little more.

I have a spare new standard head casting, piper springs and caps, 29mm inlets and 26mm exhaust valves, along with guides sitting in my garage and my thought process is running like this instead of having the present set up optimised now on the rolling road to do a bit of self porting on the head and later have the set up on the rolling road.

After looking at the DVA website (thanks for the inspiring resource) along with some good postings on SELOC I have spent the last months slowly gathering the tools I think I will need.

I am more interested in doing this for self satisfaction/learning experience than any money saving and hoping to gain some power, however I am finding that I lack the courage to start because of a couple of unanswered questions in my mind. So if anyone can answer I would be grateful.

I wish to change to manual tensioner, anything to watch out for when drilling and tapping hole?

I also believe I need to widen  valve seat insert/throat-I have a set of neway cutters for the actual seat but I am struggling to see how to do a reasonably accurate job of increasing the inside diameter of the seat by hand-any tips on this appreciated.

If anybody has done this themselves I would be interested to hear of the problems encountered and how they were resolved.

Thank-you

Albert

 

 

Link to comment
Share on other sites

I did this about 10 years ago. I was lucky enough to have Mr Oilyhands himself as mentor (he was still an "amateur" in those days. Dave ported one inlet and one exhaust for me and sent me away to tackle the other 14.

As I recall, the trick was to have a set of old valves which you turned down to different diameters and then used these in turn to check that the throats were both circular and the right diameter. I'm sure that I had a VHS video of Dave demonstrating his techniques - possibly filmed by Bernard Scouse? I'll have a dig around to see if I still have it (and see if my VHS machine is still working)

 

Link to comment
Share on other sites

I wish to change to manual tensioner, anything to watch out for when drilling and tapping hole? - See more at: http://www.lotus7.club/forum/techtalk/k-series-diy-head-porting#sthash.gvSohQQo.dpuf

Yeah, drill it in the correct place! When we did my engine a decade ago, we didn't quite trust how close the manual position was to the auto tensioner hole - so opted to tap out the auto hole to the larger bolt size instead. 

It works fine - but you need a different length of belt and I've no idea if the belt covers would still fit without modification.

 

Link to comment
Share on other sites

There is a template somewhere on here or DVA's website. Not difficult from memory. Enjoyed doing the porting for the reasons you mentioned and results were terrific although, I'm sure, not as good as Oily would have done.

Cannot comment on opening out the valves as didn't go that far, not wanting to go as far as replacing the pistons.

Just go for it.

Link to comment
Share on other sites

  • 3 weeks later...

If one of these videos comes to light I would love to view it in exchange for preserving it on DVD. As an aside when I searched the interweb for the name of the gentleman who made the video in the hope of finding some more info I stumbled accros a "knitting circle" website that discussed this video and classes quite a lot with a lot of references to secret squirrels. Must have been strange times....

Link to comment
Share on other sites

Mmm.. I remember the knitting circle..

I have read your blog, but I would be circumspect about clipping the inlet guides off, I push them back in the head to do the porting, I then mark their radial position, remove them, taper them and then refit, if this is done accurately the seats will still conform and be usable. You can clip the exhaust guides as there is very little metal removal involved.

Oily

Link to comment
Share on other sites

  • 3 weeks later...

Following a huge spring (winter?) clean I have found my VHS copy of Lorne Masons videos.I have also dug out my VHS player and a video to USB adapter to digitally capture them.
I have tried to contact Lorne to get permission to share them but haven't heard back from him - the email address I am using is 13 years old so he might not still be using it. Does anybody have current contact details for him?

 

Link to comment
Share on other sites

I have Lornes blessing to share the videos. I have captured the head modification tape (2hr 50mins) but the raw capture runs to 6GB so I am playing with HandBrake to see if I can get it to a reasonable size while retaining the current video quality. Remember that these are from 13 year old VHS tapes - not the latest HD GoPro.

Would I be able to host them on this website? I notice that if I upload a picture it says that I have an unlimited quota - wonder what will happen if I rename a 2 GB MPEG as a JPEG and try the upload...
 

Link to comment
Share on other sites

  • 11 months later...

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...