Spider Engine rebuild

jrflyboyVP2 · #1 (**permalink**) 09-24-2004, 08:18 AM

Well I just got my 76 Spider back together and running last week. I have several issues after a complete engine rebuild (by me a total amateur). I have a small oil leak coming down the side of the block from the front right corner of the cylinder head to block joint (head gasket). I used a new head gasket and oil rings and torqued to spec. Anybody know the trick to getting a good head to block seal on cam oil passages? Also I had zero indicated oil pressure at idle hot, so I replaced the oil pressure sender (gauge goes full scale when grounding lead). Now I get 20 psi at idle (hot) but the oil pressure runs about 40 psi cruising at 3000 rpm. Initially it reads about 60psi for the first 10 miles of driving or so. I suspect the 40psi is just an inaccuracy in the gauge, or even the new sender, any similar experiences? (Engine has new oil pump, new bearings, crank plugs were all there when the engine was assembled). Also it takes about 3 tries to get it started. 1) wait for fuel pressure light to go out (5sec) and crank 2) wait a few seconds and crank again 3) wait a few more seconds and crank (fires up on third try). Is this normal? The Alpha guy here in Austin told me to keep the RPM under 3000 for the first 500 miles. Any other opinions on break in?

John

**papajam** · #2 (**permalink**) 09-25-2004, 05:19 AM

Welcome to the BB, John!

This may sound like a dumb question but have the two 8mm bolts at each corner of the front cover that go into the head been installed? Also, were the threads on the head studs and nuts cleaned prior to lubetorqueing? And has the head been hot torqued yet?

A zero psi oil pressure reading at hot idle is not abnormal. As long as the low oil pressure light doesn't come on, it's OK. It almost sounds like you have a mismatch with the oil sender and the gauge; ie a Borletti sender and a Jaeger gauge (or vice versa). I'd verify the oil pressurer with a mechanical gauge.

More later....

**Roadtrip** · #3 (**permalink**) 09-25-2004, 10:36 AM

Are you venting oil into the coolant?

**Bill** · #4 (**permalink**) 09-26-2004, 10:43 AM

Hey Austin John, welcome to the board.

The fuel pressure light should go out in less than 1 second, not 5.
Could be a restricted line or weak pump...
Along with Papa, check the tightness of the front bolts and the cam cover bolts in general. Also check the gasket around the distributor, could be dry or cracked.(thats where mine was, when it looked like a front seal.)

When you get it sorted out, wait for a beautiful hill country morning and head out toward Bandera, by way of Boerne...Great Drive. Or head on down here to Corpus and say hi, do a little fishing and play with our cars.

jrflyboyVP2 · #5 (**permalink**) 09-27-2004, 07:36 AM

Thanks for the advice, I checked the front bolts under the corners of the head and they are tight. I also retorked the head to 65 ft-lbs both hot and cold (yes, I cleaned the studs and oiled them before assembly), but it still leaks pretty bad out the side of the drivers side front corner where the oil passage to the front cam bearing is. I haven't detected any oil in the coolant yet, but it is early. I did a complete rebuild and used all new gaskets and o-rings, so I am suprized at how much oil is leaking. After a 30 min drive, I get 3 little puddles of oil under the car after parking for 10 minutes. One under each front corner of the engine, and one under the bell housing. I now have 300 miles on it since rebuild, and the rings are seating much better (much less blue smoke out the pipe). The oil pressure with the new sender is a good 15-20psi hot idle, but only 40-50 hot at 3000 rpm cruising in 5th. I have been keeping it under 3000 rpm for brake-in, and put techron FI cleaner in each tank of gas. The engine is running well with a little shake at idle, but smooth acceleration and that sweet alpha sound from my custom exhaust. Unfortunately, the rear end is making all kinds of bad sounds thought. There appears to be a lot of lash in the diff, and it clicks and squeals at times like a bearing is going out. So I expect I will be pulling the head and replacing the head gasket if the oil leak doesn't stop, and I will be looking for a good used rear end.

John in Austin

jrflyboyVP2 · #6 (**permalink**) 09-27-2004, 07:43 AM

Papajam, I think you may be on to something with the sender / gauge mismatch. The Oil sender I just purchased was longer by about a half inch than the one it replaced. I had to cut part of the plastic piece which protects the electrical connector in order to clear the starter selenoid. I just ordered it online from IAP. How do I tell if it is the right one? I belive the oil pressure is ok though. The low pressure light does not come on at idle, and the oil pressure cold is about 65psi until it warms up than drops to about 40psi at 3000 rpm 5th gear.

John in Austin

Keven · #7 (**permalink**) 09-27-2004, 09:49 AM

John,

Did you check the cylinder sleeve height (or protrusion sp?) before putting
the head on? I think its suppose to be about 2mm above the block using
a high quality straight edge. Dont quote me on the dimension, Im sure
the real experts will chime in.

Good luck.

Farace · #8 (**permalink**) 09-27-2004, 09:50 AM

This might be a silly question, but are you sure the leak is from the head and not from the cam cover gasket? I had what at first appeared to be a leaking head and it turned out to be the cam cover gasket; it wasn't immediately apparent at first. I only mention it because you'd hate to have to do the head gasket over again for nothing.

jrflyboyVP2 · #9 (**permalink**) 09-27-2004, 11:36 AM

Thanks for the input, but I am sure it is the head gasket, not the cam cover gasket. I did not check the height of the cylinder liners above the block, but should have been fully seated. I did not renew them and left them in the block undisturbed. But you make a good point. if the front cylinder liner was not fully seated, than the head would be lifted slightly there and not seal the oil o-ring well. One concern I have is that the block had the older split pins in the oil passages. I tried to remove and replace them with the newer rolled pins, but couldn't get any of them out. Several were pushed in almost flush, so I pushed them further in and put a new rolled pin over top of them (the alfa guy here in Austin said that would work). Oh well, if I need to I can pull the head again in the vehicle, but I don't know what I would do different in refitting the head to prevent the leak. I suppose I would at least put a rolled pin in that location.

John in Austin

gvisconty · #10 (**permalink**) 09-27-2004, 01:06 PM

If one or more of the liners were sticking up too high, wouldn't you see oil and coolant mixing together, instead of (or in conjunction with) the external leak? What kind (brand) of head gasket did you use?

Farace · #11 (**permalink**) 09-27-2004, 01:44 PM

Did you follow the oft-repeated admonition to keep the mating surfaces of head, block and liner tops "surgically clean" and not get fingerprints on the head gasket?

DaveC · #12 (**permalink**) 09-27-2004, 02:16 PM

Maybe the new roll pins on top of the old roll pins are sticking out a bit to far. This would keep the head from properly "torqueing" the head gasket / o-rings. Just a guess.

Dave

Veloce92 · #13 (**permalink**) 09-27-2004, 04:27 PM

1. Did you have the head machined before reinstalling it on the car?
2. Did you check the top of the block to make sure it was level?

If you didn't do both of these I can almost guarantee that one or both are your problem.

jrflyboyVP2 · #14 (**permalink**) 09-28-2004, 07:14 AM

The head was a rebuilt used one supplied by Italian Motor Service here in Austin. They know what they are doing, so I am pretty sure it was machined flat. I don't know about the top of the block. I cleaned the surface the best I could, and just bolted it up. I have done cylinder heads before on honda's, and an Austin Healy sprite, with no problems, but never an Alfa. I expect I will be pulling the head off, what should I look for?

John in Austin
76 Spider

Farace · #15 (**permalink**) 09-28-2004, 09:16 AM

Did you torque the head nuts in the recommended (or I should say, one of the recommended) order? And did you go around the order several times, bringing the torque up bit by bit, rather than all at once?

When I cleaned the top of my block and liners, I carefully scraped off all the old gasket that was sticking to the block (the liners were new) and just before mounting the head I wiped the mating surfaces down well with acetone (remembering from college chem lab that acetone is used to clean glassware because it leaves no residue after it's evaporated). I also wiped the head gasket well with a clean dry cloth because I had read not to get fingerprints on it only after I had handled it (albeit not with grease-laden, just-changed-the-oil hands).