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#1
09-28-2021, 12:06 PM
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further work required
hi
when i mentioned the idler i was referring to moving it further into the oil pump by machining the custom sleeve that had been made not decreasing its diameter. this action would bring the face of the idler inline with the waterpump and all other pulleys as i thought if the belt caught the edge of the idler it could encourage its deflection off course further. i have since tried this and it has not corrected my issue although i think its an improvement on the setup. yes there are only a few components on the cambelt assembly which have all been changed at least once. i was considering buying a new belt on the off chance it was a dud however i have tried it in both directions so my thoughts of there being a tight braided strand are unlikely. But what's 20 quid for a new belt going to do after going this far... my only other thought before doing the headgasket at the moment would be if the tensioner stud was bent or worn. you may not know due to you having the older variant but the tensioner assembly is loose (in my case) on the stud/shaft but has a flat face which sits on the head. so even if the shaft was worn the nut securing the tensioner should pull it flat face to face which is what is occurring. i cant remember if someone else on the forum mentioned this but someone said the tensioner wasn't sqaure and leads off from factory. how true this is i don't know. another unlikely cause. now the headgasket topic. this would be a good time to bulletproof the engine with the mls gasket and hts head studs, not that im looking to push serious power but i like the idea of having the option there. how can i tell what notch headgasket i have or do i have to measure the thickness of the gasket when the head is removed( i doubt it as it would be compressed). I'm sure there is an indication of the thickness prior to removal that i am not aware of. i understand i can order the same thickness//notch as what is fitted or less if i measure the clearance between the pistons. the process seems simple in theory considering i have timed the engine a silly amount of times trying to fix the walking belt. is the head on dowels? if so surely you couldn't move the head.. or is it literally floating on the head studs? i have a general idea of what angle i want to push it in considering the general dynamic of where the belt is tracking and the rotation of the engine. i just hope it gets bolted down in a better position.(seems very hit and miss). the annoying thing is since messing about with the setup as per my previous message the cambelt will run forever in a day on track until you increase the revs to say 2500-3500. i have shown this in a video which i have uploaded to YouTube. the first clip is the cambelt on course and the second section shows the belt after it has tracked. it does not move further but it does not return to its original position. that's my thoughts at the moment. looking like the head is going to be coming off at some point, just need to source some ht head studs/bolts and a new gasket. i sure hope that will fix my problem or im going to break down  youtube link for my video https://www.youtube.com/watch?v=grUQbxMhMmY just noticed this guy examining his on YouTube and seems to be in the position i dont want mine!!! https://www.youtube.com/watch?v=LzVw4H10zm0 regards 
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#2
09-28-2021, 01:28 PM
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TB position on camshaft pulley
Quote:
My timing belt appears to be in that very same position since at least 9 years ago (the belt runs in a `rearmost position` on the very back of the camshaft front pulley). It worried me first but then I was told it would be okay. AND, I do know that the belt was installed by a real professional who is also an extremely knowledgeable d24 enthusiast. As far as I know, the head never came off on this engine but maybe I am wrong about that. I think it has the 3-notch fiber one. Last edited by RedArrow; 09-28-2021 at 01:32 PM.
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#3
09-29-2021, 11:39 AM
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Quote:
Quote:
__________________
1985 744 gle d24t 1985 745 gle d24t
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#4
09-30-2021, 10:11 AM
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thanks for the feedback.
how do you go about "setting the head" when there is so much slop. when you say setting the head do you mean just centralizing all the bolt holes that go thorough the head-gasket-block by installing like you said the modified bolts and then removing them for the new bolts/studs. that way everything is mostly where it needs to be and all bolts are aligned correctly? i assume in the factory they must have had a jig so that this could not be done incorrectly. If i remove the head i will measure the clearance and order an appropriate gasket to suit.
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#5
09-30-2021, 12:47 PM
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Yes Bob,
Volvo in fact had a tool for this, 9995235 (21) or you could use modded headbolts. The four pins may have their own part number as 9995234 but I`m not sure at the very moment. The four white little plastic pins/plugs have their outer ends threaded to go into the head smoothly (for fitment see illustration)... and the other end of the plastic pin is hollow and threaded inside as well, it is left-threaded BTW (to accept the `picker tool` then you can pull them out safely). Picture 4 shows this. There are (at least,?) two kinds of headbolts used in the d24 family of engines, thinner ones are visible on left, the thicker 12mm ones are on the right. Their heads have been shaved/removed to properly fit `through`. There is still some thickness left of the top to use the headbolt-tool to install/remove these home-made `alignment pins`. A 'Snap-on 12' tool is also pictured (used to handle the thicker later years headbolts) /right side, 5th picture/ Last edited by RedArrow; 09-30-2021 at 01:12 PM.
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#6
09-30-2021, 01:19 PM
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A little off-topic but for the piston protrusion they also had a Volvo tool made, 9995192 (21)
Works with the dial caliper the typical way, has its own 'clamp-bolt' on top. Last edited by RedArrow; 09-30-2021 at 01:23 PM.
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#7
10-01-2021, 10:55 AM
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Quote:
IMHO there is some slop there yes, but not enough that it would impact the coolant or oil passageways if the head was not exactly centralized. Quote:
More reading material for you, courtesy of Tom Bryant https://thosbryant.wordpress.com/201...-pump-re-seal/ : "Tom Bryant says: April 29, 2016 at 10:42 pm Jeremiah, Headgaskets make a significant difference to winter starting, but glow plugs and general engine condition are much more important. Thinner headgaskets also make a dramatic improvement to horsepower and performance. If you do decide to replace your headgasket, you should try for the thinnest one you can get away with. That means that you really must use an MLS headgasket, as you cannot readily predict, or control, just how thick a composition headgasket will be. Volvo’s original “Green Book” specifications, when boiled down to their basics, call for a piston to cylinder head clearance in the range of 0.58-0.73mm (0.0228-0.0287″). That is an overly-conservative specification. And to make matters worse, engines often left the factory with piston to head clearances well in excess of the maximum specification. I have seen situations where a 3-notch gasket was used when the clearance specifications should have dictated a 1-notch gasket. Then, to make matters much, much, worse, aftermarket replacement pistons are often about 0.25mm (0.01″) shorter than the OEM pistons, so if they’re used with the original head gasket thickness, the situation goes from bad to intolerable. The cure is to install the thinnest MLS head gasket you can. I have experimented with many, many, such thinner head gaskets to find out just how small a piston to head clearance I can get away with. The answer is just about 0.014″ (0.356mm). I have had several successful engines with that low of a calculated clearance. And, I’ve also had a few failures with that same calculated clearance. To be safe, I don’t really recommend trying to go below a minimum piston to head clearance of 0.017″ (0.432mm). To achieve such low clearances, it is generally necessary to remove layers from an MLS head gasket. Such gaskets have 4 layers. You can get away with removing any of those 4 layers *except* for the top layer. You can also get away with using a bottom layer in place of the top layer, but you have to put a sealant on the bare metal side of that layer, which would then face upward toward the cylinder head. I recommend Volvo’s “High Temperature Chemical Gasket” Part Number 1161059-9 for that purpose. If you decide to go with one of these radically thinner head gaskets, you must measure your piston deck heights very accurately, and you must make sure the piston top is square across (or level). And, you will have to measure the thicknesses of each layer of your MLS head gasket very carefully. For reference purposes, here are the layer thicknesses that I have measured on Volvo’s MLS head gaskets (which, unfortunately, are no longer available): Top layer: 0.23mm 2nd layer: 0.87, 0.92, 0.97mm (1, 2, & 3 notch gaskets, respectively) 3rd layer: 0.12mm Bot layer: 0.23mm As just one example of how a person can mix and match head gasket layers to obtain a desired thickness, here’s what I used for my latest head gasket replacement: One top layer, and 4 bottom layers. That’s right, I didn’t use the thick “notched” layer at all. The piston deck heights maxed out at 0.030″ (0.762mm), and I needed a thin head gasket, so I used only the corrugated “top” and “bottom” layers. I had several brand new bottom layers that had been removed from previously-installed gaskets. So, I combined four of those bottom layers with one previously-used top layer that had lost its rubber coating. I applied a bit of that special Volvo anerobic gasket maker to both sides of that top layer. The calculated piston to head clearance of this gasket is 0.0153″. It was installed in the engine on 6/24/2015, and to this date (4/30/2016) has accumulated over 7600 trouble-free miles. Be extremely careful with your measurements, and don’t push the envelope too far until you’re really sure of yourself. If you do this, and depending on just how thick your old gasket was, you may notice a dramatic improvement in horsepower and performance. Tom"
__________________
1985 744 gle d24t 1985 745 gle d24t
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