Thanks.
holley.com/products/fuel_sy … parts/9710
Or with viewing gauge
Back to our regularly scheduled programming. An update along with some crow.
First up was dealing with the 0 lash valve/follower/shim. Barry had said call Bean and get a new keeper and retainers. When they arrived - the keeper didn’t fit inside the spring. Called Barry - hey, Barry, were the springs/retainers stock? Oh, yeah, they weren’t. And Barry, if the solution to the previous zero lash valve was a thinner follower, why isn’t that the solution this time? Oh, it should be.
So another call to Bean, and another wait.
Meanwhile, I got the engine crane back out of storage and put the head back on the block. Does anybody do this with job with the block in the car with pure muscle? You have my admiration.
With the head, cams, etc. on, I was in position to find out what my fuel pressure was at cranking. Expecting to see something in the 2-4 psi range, I cranked away and looked at my 5 psi gauge as the needle swung past the five into the unknown (7 maybe?) and laughed at me.
So, another call to Ken at DBE - I had left a message the previous day about needing a .119 shim to go with my new thin follower, now we added a Holley fuel pressure regulator and plumbing supplies to the order. And since it was late Thursday, just before they shut down, they’re closed on Fridays, and it’s Memorial day on Monday, maybe I’ll have the parts in the next couple of weeks.
Which should give me time to get the O2 bungs welded in. And there’s some trim and cosmetic work I could do in the interim as well.
So a shoutout to 2cams and everyone else who pointed accusingly at my fuel pump, you nailed it. So, so far in this tear down I’ve got the spark plug thread fixed, so I can run a matching set of plugs, I verified a fuel pressure issue, I tightened up the AV set screws a tad giving them a better seal to the fuel feed, gotten a tube of sealant for the trumpets, found a valve with zero lash and will have that addressed. So hopefully one or more of those will address the rough running and fuel seepage. I’ll let you know in a couple of weeks.
The saga continues on this project from hell.
To update, I pulled the head and got the #2 spark plug threads fixed (the shop used a Time Sert, btw). Installed a fuel pressure regulator. Swapped the carbs front to back. Sealed the trumpets.
First road test showed no change in behavior. Rough running. Some fuel coming out of #3 throat - not under the trumpet - in the trumpet and AV. Fuel pressure was about 3.7 psi,so I dropped it to to 2.5.
Road test after that was very short - just verified that the rough running wasn’t fixed. So don’t know if the fuel pressure drop helped on the fuel issue, since that seems to require some highway driving to reproduce.
At this point I started calling local shops to see if anybody wanted to take a look at this. Got lots of - we don’t mess with English cars anymore, don’t need that business. But one suggested, after I had reviewed all my diagnostics, that I do a leak down test. Why not, I’ve got the gear.
So I did that this morning. All cylinders were 100/100. Which I though odd, so I tried one cylinder at tdc on exhaust, and the cylinder gage was way lower, so that gave me some trust in the 100/100. For all cylinders, there was a very slight hiss (when doing the tube to the ear thing) from the crankcase vent, which makes perfect sense. However, the test on #2 produced bubbles at the open radiator cap, and bubbling sounds at the ear tube when listening at the open cap.
So, fuel coming back out of #3, and a compression leak to the water jacket at #2. So the head is coming back off. Are there any other tests I should do before doing that? I will make one more longer test drive to see if lowering the fuel pressure solved the #3 fuel issue.
Then I’ll pull the head, and put the Stromberg head back on for this season.
One more item on my pile of woe. Remember the oil droplets on the right side of the engine bay? Common cause of that was oil mist coming out of the dip stick tube. So I put a spark plug boot on the dip stick. No improvement. A closer look showed oil seeping out of a crack in the front cover just above the dip stick tube. I thought maybe it was a sealing issue between the front and rear front cover sections, but no, definitely a crack. There’s been some oil there as long as I’ve had the car, but it’s worse now. I’m guessing I must have gotten overly agressive when ‘tapping’ on it during disassembly. So that will have to get dealt with, but at least now I know what the root cause is. Maybe I can seal the crack with epoxy from the inside when the head is off?
Steve,
Sorry to hear more of your troubles. As for the crack in the timing chain case, castings of this age are often porous to some extent, and once contaminated with oil are virtually impossible to get clean enough to repair by adhesive or welding. In Britain some of the aftermarket replacements have been criticised for dimensional errors such that the chain rubs on the casting.
Hope this helps,
Richard Hawkins
Thanks, Richard. You’re likely right. After some more thought, I believe the crack is underneath the chain dampener, so I don’t think I can get to it from the inside without removing the cover anyway, so epoxy would be off the table. If so, once again, the engine will have to come out. This will make the 5th time in the 9 years I’ve had the car. It’s getting a bit tiresome. Am I setting some kind of record here, for a road car?
Ken at DBE mentioned welding it up, so apparently some have had some success in doing that. We’ll see…
Personally I’ve never seen the need for those fancy pantsy leakdown testers. Spin the engine over and use a simple compression tester and tell us what the readings are.
Already did, #'s posted in another thread - 192, 189, 195, 195 psi. But I’m curious - if I hadn’t already done it, what would be the point of doing it now?
Apologies if you have quoted the compression figures before. Your posts are quite long and my RAM capacity is very limited these days. Were those figures obtained before or after you lifted the head?
All engines need only proper fuel, ignition and compression to run properly. I know there’s currently a question mark about fuel. Have you eliminated ignition?
Certainly no need to apologize. Test was done before the thread fix, yes. So I can’t swear that those were the #’s after, but the leak down pressure #’s certainly support them, fwiw. And the engine behavior before and after was the same.
Moot point now - I pulled the engine this morning. 4 hrs, a new record for me. I wonder what the rate book time is?
Ignition is points, everything is new and tested, so yes, to the best of my ability, ignition is cleared.
Are you skeptical that a head gasket coolant leak is the rough running cause? Ken and Barry think it is. But even if it is, I don’t think it accounts for the fuel coming out #3 throat. And if fuel pressure was the cause of that, why isn’t #4 the same? Riddles.
The key to diagnosing a problem is to eliminate the number of variables. Rushing forward and pulling everything apart without good cause is not reducing the number of variables. It’s increasing the number variables because another fault may have been unknowingly introduced during that process so instead of dealing with perhaps just one fault you may be dealing with several all at the same time. Since you’ve already pulled the engine out of car I can’t really offer much further advice as the engine is no longer in a condition where it’s able to run. Like I said an engine needs only a couple of inputs to run properly. You need to eliminate each of those inputs as causes. Anyway I await with interest what you discover during the teardown.
Imo, a coolant leak in cyl #2 is plenty of reason. Plus the front cover oil leak. Surprised that you don’t agree, but to each their own.
The front cover leak although of course an issue is not the cause of your running problems. Like I said - running problem is down to fuel, ignition or compression. Those and oxygen are the only inputs you need for combustion. Oil leak isn’t on that list.
You’ve pulled the head off. How do you know whether or not that leak was due to something you did during the removal and replacement of the head or whether it was a pre-existing condition before you removed the head?
A leak into the cooling system clearly isn’t good but depending on it’s severity it may not necessarily be causing the problem. That’s why you should do a compression test. If it shows up as the problem cylinder having lower compression than the others then it probably is an issue. You used a compression tester when you checked before lifting the head but used a leak down tester after reinstalling the head. The conditions aren’t the same so therefore you don’t know whether what you are measuring is the same or whether the change is due to something that occurred during removing and replacing the head. Generally if you have an issue with compression that’s severe enough to cause rough running it will show up using a compression tester. A leak down tester may be useful to check for general engine wear which a compression tester may not be reliably able to test. Ideally you should do both a compression and leak down test for a more accurate overall assessment.
If there was a compression issue, the leak down test would have shown it. It didn’t. The coolant leak has to be fixed, and I want to fix the oil leak. Whether the coolant leak existed previously or not doesn’t matter, it exists now and it’s got to be fixed (and we’ll never know anyway). What’s to be gained by waiting?
But it is interesting that the leak is in the same cyl that had the lowest compression previously, fwiw.
5 psi variance between highest and lowest reading cylinders is not enough to cause a rough running issue in my opinion. It’s well within the tolerance range of measurement accuracy. That result may no longer have proper meaning of course because the head has been off and on in the meantime.
You say you’ve checked ignition - by that I assume you mean you’ve checked firing order, spark strength at each plug, static timing, dynamic timing (i.e checking that timing advances with increased speed). I’d be crossing off compression too assuming you didn’t upset anything by removing and replacing the head.
That leads us back to fuel. You don’t need to rip the engine out to fix a fuel issue.
‘once contaminated with oil are virtually impossible to get clean enough to repair by adhesive or welding’
That just is not the case. I have lost count of the number of ali diff housings that I have had welded up due to cracks and other damage, and they don’t come much more oily than one of those. All turned out perfectly and have been reused. You just have to take what ever you need welding to someone who knows what they are doing. Full stop.
Leslie
Not sure what this is about. Are you responding to the wrong post???
2 cams,
I think Leslie is responding to my comment about the difficulty of repairing cracked and oil contaminated castings that may have porosity.
Richard Hawkins
Today’s update. With the head off, I sent pics of the head and block to Barry (the head guy) and Ken (the parts guy). Barry id’d where he thinks the coolant leak is - the passage between cyl 1 & 2 has a bit of roughness there, so we’ll skim the head to remove it. He also asked that the head be pressure tested, so that will happen too.
Maybe the bigger issue is the oil on top of the pistons and seeping in front of #1 and behind #4. And the fact that the cylinder walls are mirror smooth after about 100 miles. Barry thinks the hone wasn’t appropriate for the rings, so I’m working with Ken and the machine shop on that. Ken’s a bit mystified, because he’s sold a lot of these rings without seeing this issue, so I asked him to call Barry to discuss. As for the hone, the machinist who worked the block has retired, and isn’t returning calls from the shop. So while they they have confidence he did it to spec, they can’t prove it and it sounds like we’ll never know exactly what he did.
I’ll pull the #4 piston and take some pics and send those on, but it sounds likely that we’ll replace the rings and rehone, so the entire engine will be coming apart for that.
I was concerned about finding the crack in the front cover. Nothing to worry about there, as soon as I got the front cover and damper off, the crack was visible. I found a shop in town that thinks they can weld that up, so I’ll take it to them tomorrow.
The clamp ring on my 25D is cracked, making it difficult to clamp in place as firmly as I’d like. It turns out that Advanced Distributors has a service where they machine off that ring, and press on a solid steel ring, pinned in place so it can’t move, and thick enough where it’s essentially uncrushable. So the distributor got sent out today for that fix.
IMO, the oil on the surface of the gasket, and the coolant leak, indicate insufficient clamping, which Ken agrees with. I’m using ATP head bolts. Ken had me check to make sure they weren’t bottoming out. So far I’ve checked one, which wa .2" short of bottoming out, so no problem there. I’m guessing the others are the same, but I’ll check them, too. When the head goes back on, he suggested spraying the gasket with Copper Note, and torquing to 70 ft-lbs as well.
So, several threads in progress addressing various issues or possible issues. And who knows what else is out there - certainly a fuel issue of some sort is still a possibility as well.
