I did a compression test on my little truck a few weeks ago and #4 was around 25 psi lower than the other 3. I did the "tip some oil down the spark plug hole and try again" and it made no difference, so I deduced that the valves weren't seating, and combines with a bit of smoke when I first fired it up each day, I decided that the valve guides/and/or valve stem seals are buggared. I could see by the grey sealant around the cam cover that someone else had been in there before me, so rather than try to recondition my head, I bought a shiny new cylinder head, complete with new valves, guides, seals, springs, cam, rockers, etc etc.
Today, being a cold miserable winter day, I thought I'd spend my day turning wrenches, rather than riding my comfy chair in my nice warm house. I did think about having my local mechanic install it, but considering the standard labour rate here is at least $100 ($70 USD) per hour, I decided that I'd do it myself and save around a grand, that I could put towards something more necessary, like booze, or bike parts. Looking at my little 2.4 litre engine, I felt a little guilty, knowing that it looked so neat, and soon, I would turn it into a dirty mess.
Triton head job 5 Jun 2022 by
Terry Prendergast, on Flickr
Anyhoo, you gotta break some eggs to make an omelette, so I got stuck in. I haven't done any major work on a car in years, but I remember that the last time I took a head off a car (an old Ford with some bent pushrods after #1 son revved the crap out of it) I broke at least one exhaust stud and I had a #$%* of a time drilling/tapping the stud hole, so I was very happy that every nut, bolt and stud came out clean on the little engine, gotta love Japanese stuff. I wasn't using a workshop manual so I bumbled along at my own pace guessing what needed to be removed so I could get to the head, but eventually I stripped it down to the bare block.
Triton head job 5 Jun 2022 2 by
Terry Prendergast, on Flickr
I compared the old to the new, but by this time the rain was coming in sideways, and I was reminded of the classic song from "Butch Cassidy and the Sundance Kid", "Raindrops keep falling on my head"..........
Triton head job 5 Jun 2022 3 by
Terry Prendergast, on Flickr
That's right baby, it's a performance engine, with 4 valves per cylinder!
Triton head job 5 Jun 2022 6 by
Terry Prendergast, on Flickr
I had to use the big torque wrench I "borrowed" from work 30 years ago (I'd take it back, but that unit doesn't exist any more...) as I had to torque the new head down in increments of 30/50/78 foot pounds (well, "pounds feet", but that always sounds weird to me?) so it was well above the usual 20-25 foot pounds for motorcycle heads. Once the head was torqued to 78 (no I don't know why it wasn't 80, go figure) I had to then back the head bolts back to loose, then torque it to 20 (so I had to use my motorcycle torque wrench) then I had to mark the heads of each bolt with my fluoro yellow marker, turn them all through 90 degrees, then turn them all through 90 degrees again. I'm guessing that the final torque rating was probably around 60 foot pounds.
I tipped around a litre of oil over everything to make sure I don't cook the new cam and lifters on the first startup, and decided that I'd done enough work for one day. I figured I'd better re-install the cam cover, and this presented the first problem for the day, the 25 year old cam cover rubber seal was rock hard and didn't want to come out, so I ended up chiseling it out with a narrow bladed flat tip screwdriver, which took ages. Obviously whoever was in there before me was doing an "Economy" repair, and just splooged some grey sealant on the old seal, rather than install a new seal. I pray that mine doesn't leak, that would really piss me off.
Triton head job 5 Jun 2022 8 by
Terry Prendergast, on Flickr
And that was it. I didn't finish the job today, but it was getting dark, I was cold, tired and really sore, so I was happy that I'd gotten that far, and I packed away all of the tools and stuff as anyone can walk in off the street and steal my tools from the carport which is at the front of my house. I managed to get everything put away before I loaded up on painkillers and jumped in the old rainbox, to thaw my core.
Hopefully the rest of the job will go as smoothly as the strip did, and I'll replace the cam belt and tensioners with a new kit while I'm at it, because God only knows when/if they've ever been changed in the last 25 years. It would also piss me off royally if I broke the cam belt and bent some valves in my shiny new head, that would suck balls.....