madkaw

Well guys , my best answer is that I found some scoring on the valve stem on #6 intake valve around the seal area of the stem . I moved on to my 3.2 build and P90 head since that head was ready . Funny thing is that #6 still had a different burn with the new engine , but not oil fouled - what kind of luck is that . Once I went full sequential on my EFI - it seemed to help . I think now it’s an intake design flaw . It’s something I could tune out with injector trim possibly , but I’m going to run it . The N42 intake will go away shortly with something else .

After starting this idea - I finally got mine working . Late to the game - but hey - it does work !

Not sure what your actual experience is with these motors are , but the L28 is capable of high revving to the limit of cast pistons . For your goals you might need to step out the box of strictly getting what you want thru HP and revs. Drivetrain changes like a better gears and a slicker trans can make huge improvements . Any engine swaps will cause a lot more work, time and frustration . Bump your compression a bit and run a bigger cam and find a way to manage it with programmable EFI or triples or even SU’s

I wouldn’t fret over a CC - my MN47 head measures big also compared to spec

Those numbers seem high . Stock chamber should be around 42cc . Unshrouding the chamber is important and should be done . It’s easy and fast . I used a drum sander with a valve installed on the seat to protect things . I like the drum sander because it cuts at a low speed and has a radius to it - the bigger the better . A cordless drill will cut it fine . That extra area around the valve pocket helps flow as the valve first comes off the seat .

Lots of anxiety on that initial start up ! I was worried when I fired off my 3.2 , but it ran great - I call that luck -lol

I had no idea it would take that long , but I know you are using a homemade version .

Why so tedious?

I also have one

How is it even firing at all with no connection at the dizzie ?

Very cool- always need options . Did you check out the Jeep version?

I think it just required a spacer

That’s what I did

Yes sir

You do nice work. Funny enough I had my TIG out practicing last night - and I need it badly - the practice -lol

Things start getting really tight whenever you ad to the systems . Just went thru this on mine with similar projects . Like the push to locks. Im waiting for leaks to happen during first fire up -lol

Look at my thread on MS3x install in Megasquirt forum.

Well there was no smoking gun that I found . I pulled #6 piston to find oil around the top ring , but the second ring was pretty clean . Tends to make me believe the oil was coming from the top . I only replaced the 6 intake seal earlier , but since have changed all the seals back to the Ford seals . Inspected the piston and threw it back in . Haven’t fired it off yet - will keep my fingers crossed .

That’s pretty crazy it’s so versatile

PCV is basically located on the bottom center of the n42. https://images.app.goo.gl/s7MedL1SofYUqDMXA It actually looks biased towards front . I run through oil catch can to the PCV . I also think the #4 would get most of the junk being close to the PCV .

Okay - turns out I have an oil issue . Oil is getting into to cylinders 4-6 , progressively worse from 4 on . The oil is diluting the charge and causing a misfire - especially in 6. 4&5 seems to be able to burn it off . I removed the intake to check for vacuum leaks to find an oily film in the runners 4-6 . Runners of intake and head both had oil film. First suspect was/is the valve stem seals. I tried a different kind on this build vs my L24. Visually they looked fine . They took a lot of persuasion to install and thought maybe I used too much . Last seals were a Ford seals , which were difficult because they are finicky as hell to install. Actually replaced #6 seal while head was in motor - ran motor and still have same results . Not being able to pin this down I decided to pull the head and look at the guides and anything else . Getting good at this now I guess - 1 hour later the head was on the beach . But no smoking gun found . I ordered more seals anyway. Decision time now . Do I go deeper and pull pistons or throw all new valve seals on and reinstall head and keep fingers crossed ? I was getting ready to leave town and really wanted an answer so I dropped the pan and pulled 6. Still no smoking gun - as far as my experience(novice) eyes can tell. Got on the phone to my machinist - but didn’t hear back yet. My inspection was very quick , so when I’m back in town I will scrutinize closer . Just trying to determine source of oil . I was expecting to see a collapsed expansion ring or another failed ring . There was marks on the bores on the thrust side that were fairly significant visually , but nothing you could feel. I have an extra assembled f54 flat top short block sitting there untouched by amateur hands with 110k miles with perfect wear in the bores . Also pulled a couple of bearings and everything looked spot on. Depending on what I find or not find it might be the next plan. With the head off it makes assembly decision equal. Though this is frustrating , the hobby of engine building will have these outcomes I guess . Not being a stock engine makes this more of a challenge . Missing the L24 right about now because I enjoy driving my car - a lot ! I was hoping for more engine swap and tune - not engine swap and troubleshoot . Hopefully I learn from my mistakes

It’s oil

Well after trying about everything I could think of I pulled the head . I definitely have an oil control problem . Since this is a fresh assembly I must of got something wrong or something failed. I tried different valve guide seals on this build, but examining one of them I couldn’t say if it failed . Removing the head revealed a oil film on 4,5,6 with 5&6 being the worst. Maybe oil control rings broke, failed ? Im going back to the Ford valve seals, but really should pull a piston - ugh. Just weird it happened on the last three . Or is possible it’s just #6 and engine vacuum is dispersing it between the closer runners ? Learning a lot in this build - the hard way

I started a thread #6 fouling. I swapped to a zx dizzy and nothing changed

I will also say I’m a bit reluctant to swap the O2 sensor over for fear of ruining it with oil . Not sure what else it will tell me that nits obvious from the plugs at this point