This young fellow asked me to drop by and help him start an engine that he had rebuilt. It is a Dodge 3.0…not sure what year he said it was.
This is his first time rebuilding an engine and he has made a few mistakes leading me to believe he should have left someone else build the engine.
None of the internals were laid out as it was disassembled, so the connecting rod for cylinder 1 may now be on number 4s spot, and the lifter and push rod could be from #5. Hell the pistons could be facing backwards…or at least some of them.
He told me he used U-tube videos for guidance. He didn’t even have any manual to look up any info.
I got the distributor in and we got the engine to start. It ran good, but we shut it down when I noticed a huge puddle of oil under the engine. We never even had a chance to get a timing light on it. He had tightened the oil filter so tight that the gasket rolled right out. I told you he made some mistakes.
I also told him that on the next attempt to start it, I’d like the valve covers off. Only because I’m worried that not all the bearings were not lined up with the oil passages in the crankshaft.
Now he has the heads off and being worked on at a machine shop. Turns out the valve spring keepers were not the right ones and he had found some off when he pulled the valve covers. I also questioned him about his rebuilding and he did not reinstall the valves into the same location as they originally came from. Maybe that is why he is having the heads rebuilt.
We talked again and when I told him that he needed new head gaskets when he installs the heads, he insisted that the type he bought were reusable.
I have never heard of this and would never reuse those gaskets, for the fear that they may fail and I’d be pulling heads again soon. I wouldn’t want to make it a habit!!!
He also told me that the clearance between the open valves and the top of the pistons were a few thousands shy so he was told to double gasket the heads.
I have never heard of this either.
I’m not about to be involved in the internals of this motor because I do not want to be blamed for any internal problems.
So have any of you heard of reusable head gaskets or double gasketing a head.
Once you torque the head bolts down, the head gaskets are compressed to a certain point to create the proper seal. Once that compression occurs, the head gasket can’t be reused.
Reuse the head gasket?
You should check if the head bolts can even be reused.
If they’re torque-to-yield type head bolts, they must also be replaced.
There’s no such thing as a reusable gasket. Especially a headgasket.
I’ve heard of double gasketing a head… but I’ve never heard of it working. It’s a really really bad shortcut. Overlaying a bad gasket with a good gasket will not make the bad gasket good again. It’ll make the good gasket bad.
You’re smart to do no more than make suggestions. Long ago I rebuilt a carburetor for a coworker, and the rebuild went beautifully, but every single thing that went wrong with the car (an old beater) he insinuated that I’d done. From that day on I swore never to do the work for someone else. I’ll help them, I’ll advise them, I’ll warn them if appropriate, I’ll even offer moral support, but they have to turn the wrenches… and they have to make the decisions. In the case you describe, getting your hands dirty is a recipe for trouble. I get the willys just thinking of where and how he might have installed the rings. I won’t even torture myself thinking about the bearings. There’re 1000 things that could have been done wrong that will show up one by one when the engine gets running. I would not want my fingerprints on it.
Having said that, I commend the young fella for having the courage to rebuild an engine. Eventually, if he learns from this experience, he just might end up being an excellent mechanic… maybe even an engineer (we liked to take things apart and put them back together as kids). The biggest thing he needs to learn is to take the time to do it right. That means to get the right specs, the right guiding documents, the right tools and test equipment, and take the time to learn how to use them properly.
I did ask him about the head bolts and those he did buy new. I should call him to remind him he needs new ones again.
That is what I thought. I’d never want to have to pull everything right back off within 1000 miles because I didn’t buy new gaskets.
As I said, I don’t even want to be involved in any engine parts…even the heads. I may do them perfectly, then a keeper comes off and a valve drops and puts a hole in a piston. And it would be my fault because I torqued down the one head bolt because I was closest.
No thank you!!!
That’s pretty brave to try and build an engine without a manual. On the one engine I rebuilt I had both a Haynes and a factory manual. They were indispensable.
But you mentioned one thing that has me wondering - it’s possible to install Pistons backwards? All of mine looked the same front to back. They all went back in the same pots, but I didn’t track which way round they were. Does it only matter on some designs?
Thanks @the same mountainbike.
Now I feel better with you and Mr tester chiming in.
I think I did hear about double gasketing way back years ago, but that was a last ditch effort.
And he wants to race this thing.
I’ve rebuilt a few, and though there is a lot of good info on the net…I would never do an engine without a manual right in front of me so I can do it “step by step” and have the spec’s right there.
I have not done hundreds of rebuilds…about 8 with my dad guiding me years ago, and about 8 on my own.
Had he asked me to help rebuild this I would have been happy to give all the time he needed.
@macfisto. I’m not sure if all are marked, but all the ones I’ve done did have some indication. Either an arrow facing front on the piston, the word “Front” stamped into the piston, or a small notch at the front top edge.
If you went by the Haynes and the service manual, I’m sure it would have mentioned the marks.
I remember being told that the skirt is slightly longer on one side ( on a particular engine, and backwards the piston skirt would hit the crank when it bottomed out…if it was installed wrong.
That was on a old late 80s ford engine, but I am fuzzy on the details.
This sounds like a great way for a young buck interested in engines to learn the ropes. I’d encourage him, but maybe offer some commonsense advice. Like there’s no worry to ask an expert like yourself these questions at the beginning of the rebuild rather than waiting until after he’s done putting the engine together. And that it’s a fools errand to try this without the aid of a manual for that engine, even if it is only a Haynes or Chilton’s. Why learn something by trial and error when it is already known and easy to find out?
I’ve read in magazines of restorers using thicker head gasket material or even double gaskets during rebuilds of classic cars, when the head and possibly the top of the block has to be skimmed enough to make it flat. To return the engine to the proper piston/valve clearance and the same compression ratio. Never heard of using used head gaskets though. But if in experiment mode, why not? It might turn up something interesting.
The 89 Dakota came with a 2,5 Liter 4 cylinder, a 3.9L V6 or a 5.2L V8. tge only 3,0 Dode engine I know of was the Mitsubishi SOHC V6 that the used in cars and minivans in the 80s and early 90s.
I had a friend that built and raced hydroplanes in the 70s and 80s who used a 1965 Plymouth 273 in the 280 class quite successfully. That engine had a piston pin offset to the outside of the V to reduce piston slap and he swapped them side to side to get a little more power until the sanctioning body stopped him. They were quire strict in their interpretation of “stock engine”
I have heard of double gasketing head gaskets and which held up but it’s not something I would do.
Fel-Pro for instance even offers copper shims that look like head gaskets and which are used in conjunction with head gaskets to bring compression ratios and valve train geometry back to spec on blocks or heads that have been shaved.
While the application is smaller, many older motorcycles use copper head gaskets which are reuseable. The gasket is heated in a fire and then quenched in cold water. This anneals the gasket by softening it up and once wiped down will be good as new.
But I did look up in one of my Haynes manuals that had all the spec’s for the firing order for the 3.0. I left the book there for him to use and it was for a Dakota.
This reminded me of a guy back in high school that “rebuilt” his motor from a 442. He threw everything into buckets and did not keep any parts straight. He never rebuilt the heads, just cleaned them up. Put everything back together willy-nilly. Amazingly, it ran but it was the neighborhood mosquito fogger…
Perhaps the only way for Yosemite to communicate to this clueless young man that head gaskets are not reusable would be to pose the following question to him:
If the head gaskets were copper sheet-type, they could be reused and also stacked double. You have to spray them with sealant or they will leak water for sure.
Double gaskets will reduce compression - not what you want for a race engine. The correct solution is to clearance cut the pistons. This all takes work. You need to assemble the engine with a little modeling clay on one piston top and crank the engine 2 revolutions. Cut the clay and see how much clearance you have. Depending on the engine 0.080 inch to the intake and 0.100 to the exhaust is about the minimum for a 2-valve engine. The you re-assemble and check it again.
This is one reason why pistons have an install direction! The offset pin, as posted earlier, is another.
Why is this a problem, did he intall a bigger camshaft?
It sounds like this thing isn’t likely to run at all let alone better than factory.
This kid has money to burn…his parents are pretty well off.
He does have a job, but I think all his money from the job is his “mad money” while he lives at home for free.
This has been a 1st time project and he is excited that it even started. Thought we really never had it running more than a minute or two until we noticed the puddle of oil.
I really doubt that it will make a thousand miles before he either blows it or something else takes it off the road.
I’m all for him learning and maybe even racing this (under powered) truck, but I think that this will be a hard lesson in doing the job right.From his comments on the rebuild, I have little faith that this thing will go far.
