Perkins A107-108 top end issues

[Go.Fish]

I have a few questions about reassembling a 1970 or so Perkins A107. It needed a head gasket and some miscellaneous work.
Putting it back together now.
First off. There’s a little oil line that connects from the head to the rocker assembly. I believe I took the head to the machine shop with this little line still attached and can’t figure out how it goes back into the head. It doesn’t fit! The line is too big in diameter or the hole is too small, or the line is too long and needs to be trimmed?
Ideas?

Also. I took the injectors apart to clean them, they seem to be in good condition and required little cleaning. However now that I’ve disassembled/reassembled them I assume the spring tension should be set at an injection shop? The local guy said whoa, you’d need to rebuild them blah bla...new nozzles from the Uk, 3 weeks wait...
Can someone not just hook them up to a pop tester?

And 3rd question. I ordered a top end seal kit which included head gasket and misc gaskets. Also in the kit are 4 o-rings. I didn’t know what they were for until after installing the head and realized they’re intake valve o-rings. There weren’t any o-rings on the valves originally so I missed installing them. Not sure exactly where they are supposed to go and how necessary they are if I omit them?

Lastly. I ordered new fuel lines. What are the flares called that attach to the injectors. I guess I’d need to order a special flaring tool?

Thanks in advance if anyone could assist, even just one question

[Go.Fish]

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[Go.Fish]

Photos coming soon..

[rbk]

The oil supply line to the rocker assembly should fit, loosen the nuts holding the assembly and thread the oil line first, then work on the assembly. O rings aren’t needed. Yes you need to rebuild the injectors and pop test them. If you ordered the file line kit form parts4engines they are almost likely the low pressure lines (filter to hp pump) and not the Hp lines from the hp pump to the injectors. Those hp lines are pre flared and pre formed, each one is different and they can be hard to come by.

[Go.Fish]

Originally Posted by rbk

The oil supply line to the rocker assembly should fit, loosen the nuts holding the assembly and thread the oil line first, then work on the assembly. O rings aren’t needed. Yes you need to rebuild the injectors and pop test them. If you ordered the file line kit form parts4engines they are almost likely the low pressure lines (filter to hp pump) and not the Hp lines from the hp pump to the injectors. Those hp lines are pre flared and pre formed, each one is different and they can be hard to come by.

Ok great thanks for the informative reply! I’m just about to cut the protruding stub off this little oil line. Can’t for the life of me figure out how it will fit or how it was originally installed... the long end can’t go into the rocker assembly side because it too long so the only way it “should” fit it just won’t... stumped

Yes parts were ordered from parts4engines, super awesome to deal with! I asked about buying a single injector nozzle in the comments section when I ordered and they just threw one in!

Any idea what the pop pressure is for these injectors? Or is it a standard pressure which I can google
Much appreciated

[rbk]

Don’t cut it! Find a shop manual online they are available. It only fits one way and next time you remove it, leave it attached to the rocker assembly or mark it. Copper washers are for your injectors, aluminium ones for the return line (top of injectors). The pressure for the injectors is in the manual. I remember Fiji yachts owners group had a good digital copy of the shop manual for the 4-108 and 107.

[Compass790]

You should get a workshop manual to find pop test pressure.
If the diesel injection place says you have to rebuild injector before pop-test call that bs & go to another place.
Your pop -test shouldnt change with a cleaning if you put the shims back correctly in ea. injector.
Cost should be minimal, it's a 2 min job to test but if it needs adjustment thats different.
There is a Perkins expert on the forum so try the custom search. I think his moniker is Oldcal46 but just frm a faulty memory.
He might be able to tell you pop pressure.
Injector line flares wont be a home job, need hydraulics for that.

[jimbunyard]

Just in case you've not figured it out yet, you have to install the oiler tube loosely in either the head or the rocker assembly before mating the two and then install the other oiler tube end into the empty orifice while lowering the rocker shaft onto the head. It's probably not possible to misalign the oil delivery connection on the rocker shaft, but in case it might be, make sure that the oil hole on the shaft and the oil delivery connection are aligned.

[Go.Fish]

Well I cut off the extra tube on the oiler and fit perfect The shop manual showed a photo of the tube and didn’t appear to have that extra length on it. Still stumped but made sure both ends made good contact with the compression sleeves inside.

Motor is all back together and took a stab at getting it running. It turns over and puffs out unburnt fuel and won’t fire. I likely have the injectors out of whack at the very least. And I’m not a diesel mechanic. Going to find another shop today that is able to pop test/set these injectors. If not have been looking into building a pop tester with a bottle jack just in case

Manual says min working pressure and setting pressure are 135 and 150 atm = 2200psi

I don’t think these injectors have shims. Actually they are a different style than what parts4engines carries. Not sure where to get nozzles like these just yet

[billgewater]

As mentioned earlier those copper washers are essential in that they sit at the base of the injectors (well, on most diesel engines). They ensure that the combustion chamber is sealed. The fact that the engine does not fire might imply that the compression is too low which could happen if the copper base washers are not installed.
Usually when a head is removed the injectors are tested, repaired if needed. It is possible that one or two injectors are not "perfect" but even so, the engine should fire up. Usually injectors are overhauled in a specialist workshop as the spray is actually dangerous (can penetrate your skin with nasty consequences) and the spray pattern is also critical. Setting up your own accurate pressure device would not be a cheap process.
Also when you purchase a head gasket kit, it should come with torque sequencing and torque values. Cleaning the block top and base of the head perfectly are essential. Some mechanics also use a specialist sealant such as Hylomar, but check it out.
Best of luck.

[Compass790]

Good you got oil pipe sorted.
Yea I agree with bilgewater it may be a compression issue.
I'd be checking tappet clearances & making sure they are set at TDC on compression stroke first before I blamed injectors.
Check their spray pattern keeping clear of the spray

I find using Loctite 515 or 518 to work very well on gaskets but there are cheaper alternatives. IME you have far less trouble if you use it.

Sorry I shouldnt have assumed yr injectors are shim adjustment, if you find out how they are adjusted let us know please.
FWIW the diesel tech who does my pop-testing says they still work 150 psi either side of the factory figure for Yanmar injectors which are very close in pressure to yr Perkins ones. He still sets them at the factory spec tho as I watch him do it.

[Go.Fish]

Can’t get the darned thing to run

I found an injection shop that could test out the injectors. Trick was not to mention I took them apart. He said the spray pattern on 3 of them was a bit off but the pressure were all ok and should run as is. Spec was apparently 131 and they were all above 120. He’s going to try and source nozzles next week.

I took them home as is and reassembled everything. This time I saw in the manual the torque specs for the injector hold down nuts, they called them something that didn’t catch my eye the first time (atomizer securing nuts) 12 ft/lbs. I definitely didn’t have them that tight as the previous injector guy I spoke to said careful, they break easy.

I used the Hylomar that came with gasket set from parts4engines, about 1/3 of a 100ml tube, block, both sides of head gasket and head

So I’m thinking 3 possibilities for non starting.
1. I shouldn’t have had the head machined. Read in the manual “skimming allowance on cylinder head face” = “NIL, on no account can the cylinder head face be skimmed
2. The injectors need to be rebuilt. But doesn’t really explain why it won’t start with WD-40, warming the engine up, heat gun in the intake, spraying kerosene into intake. Not sure what else to try. Battery is cranking engine over quite quickly
3. I should’ve had the valves and seats machined. The valves looked good, the exhaust seats however had minor pitting. The seats appear the be hardened and weren’t taking well the hand lapping. But after using a drill on each valve in forward and reverse in and out the ended up looking much better

Adjusted the valves after installing the head, then rechecked clearance yesterday, still good. 0.3mm intake/exhuast. Set valve 1 when 4 was on rock. 2 when 3, 4 when 1, 3 when 2

Compression test perhaps? I need to figure out a way to do this

All I get is smoke

[Compass790]

Sounds like you got the valves done ok to me & head gasket install sounds good too.
The valve seats can be pitted ( tho not ideal) as long as they have enough clean seal area. A way to test is see if they hold liquid when head is inverted tho it's a bit late for that now you have it installed. Not leaking compression around the injectors?
Had to use 515 on our injector sealing face.

Are you sure it's bled properly & you havent touched the injector pump?
Yes thats a worry if it won't go spraying fuel in air intake, makes compression a likely suspect would be my guess.
Yea maybe a compression test is next.
Re head skimming, you should be ok if the v/v's aren't hitting the piston but yes it's not recommended on a lot of diesels but I know a fair few people who do it anyway on Yanmars



Cant comment on yr tappet setting procedure,I don't know Perkins engines so it's just general diesel advice. As long as you're following the manuals procedure you should be ok.


Try oldcal46skipper for advice, I think he rebuilds Perkins



Good idea not to tell injection shop you stripped the injectors

[rbk]

If you had the face skimmed you may be looking for a new head. It is well documented that doing so ruins the head. Good luck.

[jimbunyard]

Maybe we ought to step back a second. How was the engine running before? How did you determine that it needed a head job?

The "Battery is cranking engine over quite quickly" certainly at least suggests a compression issue; my first response would be to loosen all the valves slightly and try again.

As for starting aids, WD40 sometimes can work, but best to use the product designed as a starting aid, ether, AKA (oddly enough) starting fluid. Used properly (tiny amounts, no glow plugs) it won't cause any damage. Diesel in a mist sprayer will also work, and can be used (as can, to a lesser extent, ether) to keep the engine running whilst trouble shooting or as an aid to 'bleeding'...