vfr700f2

Hey y'all--

My kid recently bought a 92 Civic SI that didn't run. It had 240,000 mi and no compression, so we had the cylinder head rebuilt. We also cleaned a ton of sludge out of the oil pan! The car is all stock except a header, because the stock manifold was cracked.

The car ran great for a day and a half, and then the cam seized and the cam key broke. You can see the friction damage on one of the cam journals. The temp gage never showed a problem, so I assume it's oil-related. We have the head off and amazingly, there is no evidence of valve/piston contact. The timing belt didn't break either! We'll be replacing that anyway...

I read about an oil restrictor that may clog up, but a search here showed me the VTEC motors don't have that, and I definitely don't see one in the block. What else can cause this problem?

We have a good used head and D15B cam to put on, but I don't want this to happen again!!

Also, can the damaged cam journal in the head be fixed at a reasonable cost?

Thanks!!

kevin

Gunmetal_B20_Hatch

iTrader: (9)

I would get a used with the right cam.

Cant be more than $150

vfr700f2

Thanks for your reply. As I understand it, the D15B is the JDM VTi motor, 92-95, and the cam is the best-performing stock cam in any D-series motor. It may be only slightly better than the stock D16Z6 cam, but that's what's in the head I got and it didn't cost me any extra.

If my info is wrong and there's a reason to not use this cam, please LMK.

thanks!
kevin

civicgsr

If the cam seized in the head, the head is junk. The last time I saw this, I had to knock the cam out with a hammer. The journals for the cam were toast. I could be wrong though...

Sounds like the oil pump may be bad or you have a clogged orifice.

vfr700f2

If nothing else, we'll remove the oil pump for cleaning & inspection and run bore brushes thru any accessible oil passages, but if there's a known area that clogs, or another oiling problem that can cause the cam to seize, I want to be sure to take care of it before we wreck any more parts.

Thanks!!

kevin

edit: Thanks, CivicGSR. You and I were typing at the same time... As far as I can tell, there is no restrictor orifice in these engines. Am I wrong?

vfr700f2

There were some crunchy crumbs of oil sludge in the pan, but the pickup was clean, the pump was clean and clearances are within spec. The oil passages I've run brushes thru seem clear.

I sure hope whatever caused this problem doesn't happen again! I'd feel better if I knew I'd found and fixed the cause... We'll use engine cleaner in the oil for several changes and keep our fingers crossed.

Any words of advice or sympathy before we put this back together will be appreciated.

thanks
kevin

civicgsr

I don't have a helm for a D16Z6, but there has to be some way to get the oil to the head. If there wasn't an orifice there, then maybe it was missing cutting the pressure down significantly.

b16racereg6

iTrader: (2)

if i was u id stop messing with that old dead motor and find one on hear for like 100-300 bux and swap it in. thats in iop but g/l then u have a prats motor..

civicgsr

I almost completely do not understand what you were trying to say here, but the part that I did get, about getting another engine is a good idea. You may end up chasing gremlins and spending huge money whereas a used engine will probably be in much better shape.

HondachrisEJ1

I agree new motor, but to be honest it could be as simple and heavy driving wear on the bearing surfaces, or not changing the oil regularly enough to cause sludge and eventually cam wear. could be shavings from somewhere else in the motor. who knows. Clean the thing best you can, get it hot tanked you should be good with a new head on there. get a gauge to check your oil pressure if you concerned or drive hard. Easier and lest costly buy a D16z6 or get a twin cam (latter might actually be more costly). But you will have a relatively fresh motor if you spend the money to get a clean one from japan. This is your ride if your going to be proud of it don't be cheep!

vfr700f2

Thanks, all. We changed the head and it's on the road now.

To clarify, the head that went bad had just been fully cleaned and rebuilt by a trusted machine shop, and had only been on the car for 2 days. The cam and the cam bearing surfaces were in excellent condition. When we did the head the first time, we also pulled the oil pan and cleaned a ton of sludge out of it. I figure a small bit of crap we didn't clean out clogged the oil passage feeding the cam bearing between #3 & #4 cylinders and wrecked the head.

This time, we completely rinsed out the oil pan with solvent and scrubbed all the oil passages we could reach, and blew solvent thru them. We are now running seafoam in the oil, hoping to break down any remaining buildup and rinse it away.

Regarding the oil restrictor orifice, there is a passage in all D-series engines feeding oil from the filter to the head. This is the passage the oil pressure switch screws into. In a non-vtec motor, that passage has a restrictor screwed into it, with a small hole for oil flow. According to other posts on this and other boards, a vtec motor doesn't have a restrictor in this passage.

So anyway, I hope we got the last of the crap out and don't clog any more oil passages. Changing the engine really doesn't fit my plans right now. I want to avoid that if possible.

Thanks all!

kevin

vfr700f2

Update: The car has been on the road for a week and is running great.

I realized when we had the first head redone, we didn't send the rocker arm assembly and the vtec (I think) thingamajig on top of the rockers to the machine shop to be cleaned. I suspect our problem was caused by a blocked passage in one of those parts. That was an expensive lesson.