Dino Restoration

Jon,

how about a gauge like this -

http://www.dinoparts.de/content.php?sID=72cf7a2d05258191a283d87505eecdc1&tpl=shop&mode=details&mID=-6&fID=1&kID=243&pID=358&cur=EUR&lng=en&page=1



Pietro

 

I had exactly the same on my recent engine rebuild, will post up later with details, gotta go out.......... right now!!

 

Ineresting. The part is listed under the 206 section. Anyone here have one? Does it work on a 246?

Mark

 

You should really check it with a mechanical oil pressure gauge to be sure it's at the proper pressure, just for peace of mind. Maybe Jim has one.

 

Nice catch. I'm sure you're really happy you made the engine test stand now!

I haven't responded much to this thread Jon, but I've got to tell you that for nearly two years the first thing I do after booting up the computer is log onto FerrariChat and look for new posts on this thread. It's been an amazing adventure for not only you, but for all of us who view this site. Congratuations on all the work so far and best of luck in 2008.

 

Jon - please allow me to chime in. I have been down to visit John and his project three times now. It is simply amazing to seen how well he has put everything together.

Here is the saga on the engine. There is much to be learned by all.

Jon and his trusted mechanic turned over the engine with the starter, to find a transient rise in oil pressure on the mechanical gauge (reported to be 80 psi). Then when he started the engine the pressure did not rise. Zero. They did a number of appropriate checks and double checks, and were appropriately reluctant to proceed.

I came down the next day to try and help out. I was skeptical about the zero oil pressure. The mechanical gauge was reading zero. However, there was oil flow to the pressure gauge (at the high point of the engine). I thought that it might be a pump-prime-ing issue, and John accordingly primed the oil pump via the oil filter outer circumference and the pressure release valve. No improvement. I then removed the oil pressure gauge from his car and wired it to a new pressure transducer. Zero after start. We then used the original pressure transducer. Zero. We then pulled John's other Dino close to the engine stand. We connected ground between the two cars with a jumper cable to chassis and engine. With a long wire, I connected the pressure transducer on the engine we were working on to the wiring harness of the car parked next to it. Ignition on and zero pressure when we started the engine on the stand.

Hence, 3 different pressure transducers, 3 different gauges, all reading zero. I was convinced that this was not a measurement artifact!

We ran the engine for approximatey 15 minutes in several cycles, first to try and generate some oil pressure, then to tune carbs so that it would run on its own. Stepping back a few minutes, we first checked the continuity of the idiot light transducer at the oil filter input hose. This immediately recorded the .8 bar necessary to turn off the light, suggesting about 12 psi of pressure. Hence, without load, at idle, there is little danger of causing damage.

Anyway, after a fair amount of deductive reasoning, my friend John Amette, Jon G. and I arrived at the only explanation for the symptom, which was a large shunt of oil to a low pressure site. The likely culprit was loss of one of the two plugs on the end of the main oil passage running through the block. Oil flowing out of either end would simply fall back into the sump.

Jon was about to undertake removal of the bell housing-intermediate housing-flywheel to inspect the flywheel-end plug. I suggested that we first remove the oil sump plate and inspect. Low and behold...there lie a plug. Unbelievable!!!! I have never seen this.

Now we had to make a decision. Was the plug from the flywheel end or the timing chain-end of the engine? Jon's friend on the east coast settled the issue when he observed that only the timing chain-end of the engine would allow the plug to fall to the sump.

Unfortunately, I believe we have to separate the engine from the transmission to remove the timing case cover and associated parts to get to the front of the block (I have to double check this..we may not have to). If we do not have to separate the transmission, then we do not have to dismantle the flywheel end.

Now, how did this happen? John had the engine dipped in solvent to clean oil passages and to strip paint for restoration. Could the caustic agent have removed rust from around the plug, thereby loosening it? Jon is sure that it was not removed by the stripping company, or by his engine builder. I suspect that the caustic agent contributed to it loosening in its seat in the cast block. When they first turned the engine over with the starter, the 80 psi blew the plug right out. From that point on there was no measurable pressure.

More to come.

Jim S.

 

Sorry but you do not get 80psi from cranking the engine over especially from new and unprimed.

Priming these engines can be nightmare. You either have to spend a lot of time priming these, oil filter, heat exchanger etc or if fitted back in the car, tow it up the road first. That is the quickest way.

I suspect it was the compressed air!!

The plug is from the timing chain end and is the gallery plug in the engine block.

 

The Doctor is at work!! I LOVE reading this stuff...you guys are just great!! Very interesting to us mere mortals....keep up the good work!!

 

Tony, the compressed air came only after there were many attempts at reading oil pressure. The plug had already dislodged. The 80 psi reading was the very first, transient reading of the mechanical gauge upon cranking with the starter and the sparkplugs out. I agree, sounds high. It could have occurred upon starting the engine and was not noticed that the gauge initially read 80 then went to zero. Furthermore, the mechanical gauge is likely inaccurate.

Yes, the plug is on the timing chain end. We are to attack this end this morning. More to come.

Jim S.

 

Jim

You dont have to split the engine/gearbox but you need to remove the lower studs, it is much quicker and simpler to split it.

I dont feel it was rust holding it in either, looks too new to me, more than likely the engine builder removed it and didnt put the new one in properly.

Anyway at least you found the problem and know the cure which is a damn sight better.

Good luck and keep up the good work. Just a shame its got to come apart again.

Tony

PS Even with a GR starter, plugs out etc you would be very lucky to even get oil pressure at the first attempt. I have heard stories that some engine builders pump LP (>30psi) compressed air in the oil pressure sender tapping to assist in forcing the oil around. Perhaps they did that and blew the plug out without realising it. Also check the oil pressure adjustment, if you got 80psi at cranking you could be in for a shock at 6500rpm!!

PPS not being critical just trying to understand how it happened!!

 

TonyL - Thanks for the input and suggestions. Yes, removing the 4 studs under the timing cover would allow access to the timing chains without removing the transmission. However, there are two considerations in favor of removing the bell housing-intermediate plate and the transmission. First, I have received opinion from a trusted expert (John Amette) that the "emergency" approach of removing the studs often leads to leaking at the junction of the transmission and timing gear cover. He advises against it if the engine is already out of the car. Second, I wanted to inspect the rear plug to make sure that it was correctly seated.

Well, this is what Jon and I did today. We removed the bell housing and intermediate housing, the transmission, and then the timing gear cover. As expected, the oil-galley plug behind the timing gears was missing (and on the bench, having been found in the sump yesterday). The flywheel side oil plug appeared to be seated correctly. There are obvious signs of someone having struck the flywheel plug with a punch, as the new black paint was chipped missing near the center. The plug on the timing gear side, however, was unpainted, and never punched. Hence, the assembler apparently did not seat it by striking it with a punch.

Everything else appears nominal. By the way, these plugs are concave, and are to be seated by inserting and then striking sharpely with a single blow (using a punch).

As an aside, I should have mentioned yesterday that when we introduced air pressure (after not finding oil pressure) into the filter center conduit, the crankcase bleeder tubes were allowing air to bleed from the crankcase, hence, there was little pressure build up. I modulated the crankcase pressure by occluding the breather hose with the palm of my hand, but DID NOT WANT TO ALLOW SIGNIFICANT psi in the crankcase for fear of blowing out the front or rear main seal.

We await arrival of the new plug and appropriate gaskets from GT Car Parts.

Jim S.

 

Good you found the problem Jon and Jim. Expect you will talk seriously with whoever cleaned the block. Good that they removed the plugs. Bad that they only seated one. Plug is probably fine, just needs its Whap. You want to seat those plugs with a Good Whap. One that leaves a mark. You are giving us all a great education. Keep rolling.
John

 

I suggested to Jon, many months ago, that he start the engine on a test stand before he installs the unit back into the car. I believe he is now a believer. There were several issues, other than the oil pressure, that were better identified and resolved on the engine-stand.

The primary purpose for my running Dino engines on a test stand, however, is quite different. Yes, it is important to identify those gremlins that arise following a rebuild before installation, but more importantly, it affords the opportunity to retorque the heads and re-adjust the shim-cam clearance before installation in the car.

The Ferrari workshop manual (owner's manual) calls for re-torquing the heads and shim clearance adjustment at 7,500 miles, I believe. It may be less (I do not have the manual in front of me). My cynical approach to life leads me to believe that few, if any, dealers did this at the first service (in 1972, for example). It is back breaking work. A real pain. This is one of the reasons that the cams failed frequently in Dinos (failure being cam lobe wear).

Running an engine on the stand for 10 days, or so, represents 10 hot-cold cycles of expansion of the head and gasket, and seating of valves into their seats. I believe this constitutes a reasonable approximation of first service, and therefore represents a good time to remove the valve covers, retorque the heads, and remeasure shim-cam clearance.

Here is my question. How many believe that it is necessary to retorque and re-shim after an initial break-in? Of those who have rebuilt engines, were the head bolts loose? Were the shims out of adjustment? Or are we simply following, in the manner of Lemmings, an unnecessary admonition of a manufacturer trying to support its service network (with unnecessary revenue)? Of the 10 Dino engines I have rebuilt, none were found to have head bolt torque issues or shim clearance issue after run in.

I do not wish to enter a debate akin to flat-12 cylinder belt service, but even out of the car, removing valve covers and cams for retorqueing is a pain.

Your thougts?

Jim S.

 

I know Dennis McCann always ran in engines. He started out with a 160 degree thermostat so they ran slightly cold. He set ring gap at the tight end of the tolerance. He ran them for a good while (not sure how long but maybe 24 hours over a span of days) and varied the RPM's from time to time. Then he checked the shim tolerances and I'm sure the head stud torque. I believe he told me the shim tolerances changed very little usually but occasionally one would be off by a thou or so. I thought the factory spun the engines with electric motors for a good while to bed the rings and make sure all was well with the engines before installing them in the car. Cheap insurance to run the engine in on a stand in my estimation. So much easier to check for leaks and other problems with the engine out of the car. I would also double check the tightness of the banjo bolts on the carburetors during and for a while after the engine break-in period. The fiber gaskets can shrink a little after heat cycling and lose their sealing compression enough to leak. That happened on my GTS when I rebuilt the carbs and I know those banjo bolts were tight initially.

 

Hi Jim

I haven't rebuilt many Dino engines but have spoken with a guy who has rebuilt over 100 Dino engines in his career. His opinion is that the heads do not need to be re-torqued but the shims & chain tensioners do definately need to be checked after 500 miles. My recent rebuild i never touched the head bolts but did check the shims, only one shim needed to be changed and that was still within tolerance.

Whats more of a mystery is the running in procedure. I have spoken to many a engine builder and they all give good advice...but its all different.

Some say vary the engine loading, use running in oil and change it after 100 miles. All of it is very plausable, but the most radical one i heard was run the engine at 2000 rpm for 20 minutes, 4000rpm for the next 20 mins, and 6000rpm for the next 20mins. Change the oil and filter and away you go!! The idea is to bed the rings in as quickly as possible.

I followed this route but not so radical, 2500rpm (max) for the first 150miles, 3000rpm for the next 350 miles, change filter, 4000rpm for 500 miles, change oil from running in oil to a good grade of oil. One thing they all agree on though, do not let it idle for too long a period otherwise the bores will glaze up and you are......

Glad you found the problem and you will soon be on track. I agree on the studs, your more than likely to break the casting or strip the threads. Thats why i said it is much easier to split the engine / gearbox.

Tony

 

Greetings Gentlemen,

Before you continue, please read this and then carefully reconsider your deduction that there is little danger of damage to Jon's engine.

Jon, you said that, upon initial start, "It ran a little rough because none of the carbs had been adjusted. No water leaks and no oil leaks. A problem though. The mechanical oil pressure guage registers 0." Is it fair to imagine that it ran for several minutes with no pressure? Jim S, you said that, on the following day, "We ran the engine for approximatey 15 minutes in several cycles, first to try and generate some oil pressure, then to tune carbs so that it would run on its own. Stepping back a few minutes, we first checked the continuity of the idiot light transducer at the oil filter input hose. This immediately recorded the .8 bar necessary to turn off the light, suggesting about 12 psi of pressure. Hence, without load, at idle, there is little danger of causing damage."

With all due respect, I have reservations about that last sentence. Firstly, as you know, oil "flow" does not constitute pressure. I would suggest that, once the sender/gauge fitting was screwed back in, the 'leak' merely increased. Further, the seeming 12 psi pressure at the filter input hose may have been the result of the head of pressure from the pump meeting the restriction in the filter assembly, likely greater than the actual pressure of the oil upon exiting the filter (in this case). Lastly, and here's the foot-stomper, the hemorrhage occurred in the main galley just after the filter...PRIOR to the critical components of the engine!!

Take a look at the attached Dino Engine Lubrication Diagram. Item 9 is the "idiot light transducer." Item 1 is the oil filter. From the base of the filter, oil flows into the main galley, then up the front of the block and takes a ninety to parallel the crank. That's where the front plug blew out. I propose that little (or no) measurable oil pressure existed beyond that point. Crank, rods & cams are downstream.

As I once told John Corbani, I'm not a professional mechanic, and I am most certainly not an expert. However, in nearly thirty years of aviating and over forty-five years of wrenching on cars, I've experienced that continued operation (even at idle, rod bearings can take a pretty good pounding) of any engine or gearbox with zero oil pressure generally results in moderate to severe damage.

The bottom line is, Jon, your engine apparently ran for more than fifteen minutes with essentially no oil pressure...just as the gauges (all of 'em) indicated! Further disassembly & close inspection of mains & rods, plus cam 'cradles' & caps, would not be a bad thing ('easy for me to say!). The investment of a bit more time and money could reward you with peace of mind and assure your engine's longevity.

Good Luck,
Coop
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Coop, thanks for your thoughts and insight. And yes, your concern is appropriate. However, please allow me to add a few thoughts.

First, my Dino, when hot reads 5 psi when at idle. It does not take much pressure to lubricate the crank and cams. Second, the cams are not in need of large amounts of oil. Not a great deal of load, and what is there is distributed amongst 5 aluminum caps.

Finally, and quoting for clarity, "Lastly, and here's the foot-stomper, the hemorrhage occurred in the main galley just after the filter...PRIOR to the critical components of the engine!! " If one examines the lubrication diagram, you will find that the hemorrhage occurred at the end opposite the filter, hence, oil flowed all along the galley that distributes (by gravity) oil to the crank.

We will likely be removing one valve cover to inspect a cam. I have spoken with a few others who feel that it is unlikely that damage was sustained.

Thanks for your input. It is helpful to consider all opinions. More to come.

Jim S.

 

OK.
Thanks for hearing me out ('guess ya didn't have a choice). I figured you guys might appreciate the devil's advocate's opinion! Having said that, could you help me with a couple of things, Jim?

"As expected, the oil-galley plug behind the timing gears was missing (and on the bench, having been found in the sump yesterday). The flywheel side oil plug appeared to be seated correctly."
Did I misunderstand those initial observations? Check out Jon's recent post 1865, 1st picture. 'looks like the timing cover (front) end of the engine. Also, just for grins, refer back to post 1445, pics 20 & 21. There's the little bugger & it looks virgin. Ahhh, the benefit of 20/20 hindsight.

"If one examines the lubrication diagram, you will find that the hemorrhage occurred at the end opposite the filter, hence, oil flowed all along the galley that distributes (by gravity) oil to the crank."
Did I misinterpret the diagram? I believe it shows the timing cover/oil filter end of the engine on the left, which would place the offending plug in line right after the filter & before the majority of the engine.

On the bright side, I'm sure that a generous amount of assembly lube and specific cam lube were applied on build-up...definitely a good thing. Speaking of assembly, Jon, have you had the heart to bring the engine builder into the loop & get his input? He's probably got a vested interest; I'm sure he has an opinion, too!

Carry On & Good Luck,
Coop

 

Coop - my bad...

You are correct. I was writing one thing and picturing (in my mind's eye) another. We rotated the engine during disassembly, and I was picturing sitting at the other end removing nuts and bolts.

Yes, you are correct. The plug that came out was on the same end as the filter.

That said, one of the tests that we did initially after starting and finding the lack of oil pressure was to insert a clear plastic tube into the orifice where the pressure transducer sits. Oil flowed up the tube, which had at least a 1 foot elevation before it curved down into a bucket to catch the oil. I held it this high to see if oil would reach the heads. That provided some comfort that oil was flowing by pump action, albeit with virtually no pressure. Hence, oil was finding its way down the galley to the opposite end (thus traveling entirely over the crankshaft and its oil passages). And, it appeared, the pressure was sufficient to raise the oil to the level of the cam shafts.

Yes, there was assembly lube everywhere...in generous amounts.

Thank you for correcting me. It took a few minutes picturing in my mind what you were saying, and what I had reported. I was incorrect.

Jim S.

 

'though our opinions may vary, our goal is the same: A healthy engine for Jon.
I'm known to be a bit anal as regards safety, security and survivability. You may recall that I expressed concern in the past that Jon & his builder appeared not to change out the OE head studs to the superior ARP offering. Corbani, and others (you?), had already shared horror stories of failed fasteners. Regardless, I believe the path that was chosen was simple: If it ain't broke, don't fix it.
Hey, I'll be glad to represent the extremely conservative camp.
Cheers,
Coop

 

Guys,
The suspense is killing us. You'd think we were in the middle of a holiday season!
Any updates?
Coop