head carnage! Even though it only had like 350 miles on it I totally wiped out a cam lobe and bucket. The primary damage was on #3 intake, but there was signs of failure on a few other valves.
My first instinct was to blame the buckets, and I still think they were the first thing to fail. I had them hardness tested and they only measured out to ~35 HRC. I called SuperTech and they told me they should be 60+ HRC, then walked it back saying I couldn't really measure them because of the nitride coating and needed to use Vickers which I don't have access to. I still don't really have a definitive answer; bad buckets, bad cam, break-in problem, valve spring pressure... or a combo. Extremely disappointing after pouring over the thing for so long in 2019. I did do a compression and leak down test and everything checked out fine.
When I pulled the head I also found some odd spots of pitting/corrosion on #1 and #4 that I didn't like, so the whole think got yanked to go to the machine shop. They told me 3-4 month lead time, and I laid awake trying to think of other engines I could swap in that I'm actually interested in. (currently unless I can somehow fit a Ferrari F131 v8 in there I'm not that excited about it).
I also found two things which made me glad the cam ate itself, in a roundabout way. These are things I wouldn't have seen until they caused some kind of problem. First was the alignment nub broken off of the timing gear. It didn't appear to have slipped at all but will be replaced with a steel gear from KL Racing.
This one was kinda scary, transfer tube o-ring into the block was pushing out! I never had an oil pressure problem and the bearings bear witness to that... but I'm not sorry the cam drove me to find this before it blew out.
I dropped the engine off at the shop on December 4th, they didn't touch it until memorial day weekend. I just got the short block back on July 8th and don't even have valves for the head yet. But they're the best shop for Volvo stuff I can get to around here so I just had to wait.
The block was thankfully an easy job, they checked bearings which were all fine (Mann filter did it's job handling any material from the cam), refinished the cylinders and put in a new set of rings (for posterity rings were gapped to .006"/bore-inch).
The head turned into another total snowball. I needed new buckets, easy, and a new cam... I'm not going to run an IPD cam so I started reaching out to Sweden. Looked into Enem and KL Racing then started emailing with Erland Cox. After discussing my setup he recommended a cam grind he has done at Kyrk Motorsports for his cars.
Specs are: 14,7mm lift in, 14 mm out, 267-264 at 0,050" and a lobe separation of
108 degrees. Pretty big compared to the RSI cam! It should be a better match for the turbo size. Pretty aggressive ramp angle on the intake lobe too.
I had the cam and the new buckets REM micro-polished then dropped them off at the shop. Then it got all complicated. The Erland cam has a ~3mm smaller base circle than the RSI cam and it's more than I can compensate for with different lash caps, which means I needed to have Ferrea cut me a new, slightly longer set of custom valves. To top it all off the valve springs were binding on the new monster lift... because of course.
Step one was to address the coil bind. My spring install height is at 1.550" and needs to be more like 1.650". There wasn't an easy way to get there. It took several calls with Ferrea and a lot of me thinking to come up with a plan. The basics are: the valves need to be slightly longer so that length can be added into the install height, I can remove .025" from the lower spring locators, and I can use .050" offset keepers. This adds too much height, so I then have to move the groove down the valve stem to hit the 1.650" target.
There was one more problem with it: with the .050" offset keepers they would interfere with the shoulder of the lash cap on the valve tip. They're .080" lash caps with a .090" shoulder, Ferrea said they would not remove any shoulder from that unless it was a really tight fit on the valve. So, I added .020" in length to the valve tip and bought .060" lash caps from KL Racing. They have .125" shoulder that also would have interfered, but luckily I have a generous friend with access to a magnet surface grinder so he's going to cut them down to .090" for me.
To prove how annoying it was for me to figure this out, this is the spreadsheet I had to make to get my head around how all of the measurements interacted.
One side benefit of this whole thing is that I'm going to end up with better spring pressures. I'll be losing 30lbs on the seat down to ~100lbs and be at 265 over the nose. Both of these line up perfectly with what Erland recommends with his own springs.
All of the back and forth with me, Ferrea and the shop ate up a bunch of time and was honestly just stressful. I was hoping I was paying the other people to figure it out for me, so now I just have to hope everyone's measurements tie off. The new valves are on order and will hopefully be here in the next week or two. If I'm lucky the rest is assembly (if you haven't noticed I am not lucky).
After I dropped all this mess off back at the shop in December I needed a way to keep myself busy. So I decided to tool up and try to learn new skills. I bought myself a luxurious Christmas present in the form of an Everlast 210ext tig welder and a W375 water cooler. I have barely used the mig, my Dad always ended up doing most of the welding, so I was coming into this COLD. Thankfully I really took to it, have been enjoying the challenge and spent the past 6 months looking for stuff to build which I'll get caught up on next.