Another one bites the dust
 

Well the new 2276cc I got for the street bug died. It will run but has no power and back fires through the carbs over 2k. Pulling a valve cover confirmed my suspicions, exhaust lobe for 2/4 went flat. I'm guessing the motor wasn't broken in properly since it had less than 1000 miles on it. The stocker went back in for now while the big lump gets rebuilt. I'll get some pics up when I do the autopsy.

I always hate hearing failure stories, but that's exactly why I'll always beat the conversion drum. My vote is STi! I'll still be waiting for the gory pics though...

Jason

That sux. That is why I have an hour of run time on my type 4 and have pulled the lifters for inspection twice in that hour. Let us know what you find.

That sucks. Sorry to hear the news.

it is too bad Humble.Although keep us posted on what you will find...

sorry to hear that man...

I started the tear down a couple days ago but we lost our internet connection a couple days ago at the house, a hazard of mountain life. Can't upload pics until it comes back up :P

However, I got the motor down to the short block and started taking note of the parts. Pistons and cylinders look good, new rings and a re-hone should freshen them up. Heads are a mini wedge port 40x35.5 with scat 1.25 ratio rockers, also in good shape. So far everything looks good, but I did find glitter in the oil when I drained the motor so I'm going to check all the bearing surfaces when I can get to them.

Next, I need to find a strong mid-upper (3k-6k) cam that will work well in a 2276. My parts list so far is cam, lifters, bearings and possibly another set of push rods. I've been pondering the idea of rebuilding the motor in my spare aluminum race case but I haven't decided yet.

Finished the tear down tonight and there's some good news and bad news besides the cam.

Here's the cam and lifters, #2/4 exhaust is almost gone and the lifters for that lobe are concave.
http://i93.photobucket.com/albums/l4...1.jpg~original

http://i93.photobucket.com/albums/l4...0.jpg~original

The #1/3 intake and exhaust lobes were starting to go and the lifters for those lobes were also concave. Cam bearing looked okay so I think the oil filter was doing it's job.
http://i93.photobucket.com/albums/l4...7.jpg~original

Turns out the crank was a 78mm instead of an 82mm making the motor a 2165 not a 2276 but it turns out the crank is a forged DPR 78mm unit.
http://i93.photobucket.com/albums/l4...8.jpg~original

bearing surfaces aren't too bad either
http://i93.photobucket.com/albums/l4...7.jpg~original

I'm guessing these are unitech rods but I could be wrong
http://i93.photobucket.com/albums/l4...2.jpg~original

I'm worried about this bearing set though you can start to see metal transfer
http://i93.photobucket.com/albums/l4...5.jpg~original

http://i93.photobucket.com/albums/l4...6.jpg~original

Not sure if I should keep the rods or upgrade to H beam rods. I'm not sure if these rods will be up to track duty.

Heads looked good, 1/2 side was a little rich or wasn't burning as hot as the rest and I need to find out why. I think it could be related to the accel pump problem I had on that carb.
http://i93.photobucket.com/albums/l4...4.jpg~original

The 3/4 head looks good
http://i93.photobucket.com/albums/l4...3.jpg~original

The plan is to rebuild the motor in the spare race case, bump compression to 9.5:1 and use a CB #2246 cam (Adv. Duration 314° / Dur. @ .050" 260° / Lift w/1.25:1 Rocker Arms .514").

Could it be that no. 3 exhaust valve seat has sunken a little?

Upgrade to a set of CB H-Beams. They are not very expensive, and are bulletproof. The Baron runs down the strip with CB H-beams without issue.

Pete

Wally, I think the contrast makes it look sunk in but when I double checked all the valve they were okay.

Pete: I run a set in the other motor as well and I didn't want to spend the money, but I think I'll get a set so I don't worry. I want this motor to be bullet proof.

I got the case back from machining and I'll start pre-assembly today to figure preliminary deck height and rod length. Looks like (on paper at least) the combo should be good for 170-ish with the heads being the limiting factor. :)

Hey Humble why don't you contact Thorsten here on the site(he sells the dry sump pumps in the for sale section)-he makes bullet proof lifters(not cheap-but then again no headaches).

Regards,Arnoud

Believe me I would love to get a set but unfortunately it's not in the budget :( As it is I'm splurging to get the H-beam rods and that's a stretch. Once I find a job the sky's the limit on parts and I'll probably toss a set of those fancy lifters in the race motor if I can't find a set of ceramics by then.