Nick Jones Posted October 17, 2023 Posted October 17, 2023 It looks like you have (amazingly) an original, unmolested and relatively unworn engine. A good clean out, fresh bearings and gaskets and away you go. Probably even got decent memory on the valve seats.
Escadrille Ecosse Posted October 17, 2023 Posted October 17, 2023 1 hour ago, Nick Jones said: It looks like you have (amazingly) an original, unmolested and relatively unworn engine. A good clean out, fresh bearings and gaskets and away you go. Probably even got decent memory on the valve seats. This ^^^
PeteStupps Posted October 17, 2023 Posted October 17, 2023 Yeah sorry for derailing the thread talking about balancing - that was intended for your future development not the immediate term. As Nick says it looks like you've got a surprisingly original engine there so shouldn't require much to recommission and run around for as long as you require.
Nick Jones Posted October 17, 2023 Posted October 17, 2023 As a follow up to my previous remark, that’s exactly what I did when I fitted my first Vitesse engine (which was a real mk2 Vitesse engine, even though it’s previous home was a Mk3 GT6). New bearing shells, (Glacier not VDV), pump and chain. Didn’t take the head off. Did 70k on that engine. Did have the head off about 5 years in as it burned no.6 exhaust valve in France and then a completely different gas-flowed head in 2008, but the bottom end lasted until 2015 before being retired for its oil habit. Now in GT6 after shells, rings and a hone. Still has an oil habit…. And makes odd noises. Needed boring and new pistons. Crank is still perfect.
egret Posted October 17, 2023 Author Posted October 17, 2023 Don't worry at all, it's all great info and good things to think about. While I've read around many of the subjects here, it's mainly been on the internet where you're never quite sure how reliable the info is. I'm going to ignore the fact that this is also just information on the internet, because enough of you lot have done this and it feels a lot more reliable than much of the info out there. I'm sure I'll come back to read this when my goals require more rpm's. The update for now is that I've got the water pump and head nuts off, but the head is stuck on. So I'm planning on removing the studs as part of a multi pronged attempt to un-stick it tonight (other prongs include levering off exhaust ports and engine frame, hitting with mallets, and possibly filling the cylinders with string). I've also done some algebra and got a spreadsheet ready to calculate the current compression ratio and head volumes needed to attain the target CR (I think I've settled on 9.5:1). I just need to enter the measurements and it should spit out the target volumes. I can then double and triple check this before sending it off the the shop.
Escadrille Ecosse Posted October 17, 2023 Posted October 17, 2023 1 hour ago, egret said: The update for now is that I've got the water pump and head nuts off, but the head is stuck on. So I'm planning on removing the studs as part of a multi pronged attempt to un-stick it tonight (other prongs include levering off exhaust ports and engine frame, hitting with mallets, and possibly filling the cylinders with string). If you can extract the studs a couple of good thumps with a hide/rubber mallet on the plug side of the head will do the trick. If you can't get all the studs out then refitting the water pump housing gives you something to haul and shoogle (can't think of the appropriate southerner word atm ) to loosen it off. Never had any success with the string idea except for supporting valves while removing the springs. Basically the leverage is wrong and you risk filling the bores/rings with fluff. Which WILL mean extracting the pistons.
Nick Jones Posted October 17, 2023 Posted October 17, 2023 Getting the studs out is key. The ones on the manifold side are the stubborn ones usually
yorkshire_spam Posted October 18, 2023 Posted October 18, 2023 (edited) 21 hours ago, Nick Jones said: Getting the studs out is key. The ones on the manifold side are the stubborn ones usually I know it's probably unnecessary outlay/spending, but on the 2 engines I've rebuilt I budget for a set of ARP studs/nuts and then if the head studs don't play it allows a more brutal approach to removal: Edit: Re-paste image from google hopefully without linking this time! Edited October 18, 2023 by yorkshire_spam
JohnD Posted October 18, 2023 Posted October 18, 2023 No truer words than above (but your link doesn't work, YS) Egret, heads are usually glued down by the studs. Get them out, and your malleting and prying will get it off. As for string in the bores:
JohnD Posted October 18, 2023 Posted October 18, 2023 (edited) Duplicate Edited October 18, 2023 by JohnD Duplicate
JohnD Posted October 18, 2023 Posted October 18, 2023 On 10/17/2023 at 8:47 AM, yorkshire_spam said: I'd happily do that... if I had a lathe or access to one! We do the best we can with the tools/facilities available! I wonder if rubbing the skirt on a sheet of abrasive, on a sheet of glass, as for truing an oil pump body, would do the job? Slow, but it's usually no more than a gram of metal to remove. John
Escadrille Ecosse Posted October 18, 2023 Posted October 18, 2023 2 hours ago, yorkshire_spam said: I know it's probably unnecessary outlay/spending, but on the 2 engines I've rebuilt I budget for a set of ARP studs/nuts and then if the head studs don't play it allows a more brutal approach to removal: Standard head studs are absolutely fine for all applications and a fraction of the cost of the ARP stuff. The standards nuts are made of cheese. The solution as given me by Tony Lindsay Dean is to use Rover Metro nuts in either plain or flanged variety as used by the fast Mini boys. And dead cheap too. The Metro nuts will take 65 lbs.ft of torque on the standard studs. Unlike the standard nuts which struggle with the book values. See my describtion in the link that Pete posted above. 2
Escadrille Ecosse Posted October 18, 2023 Posted October 18, 2023 7 minutes ago, JohnD said: I wonder if rubbing the skirt on a sheet of abrasive, on a sheet of glass, as for truing an oil pump body, would do the job? Slow, but it's usually no more than a gram of metal to remove. John Thread hijack again but pistons are usually very close in weight. The amount of metal removal required is minimal. A lathe is not needed. The two methods told me by some very respected engine builders are to use a drill to remove metal from inside the piston around the gudgeon bosses and/or a Dremel and carbide tool and remove metal from the inside of the bottom of the skirt depending on how many grams need to come off. I have done both over the years and never had a problem with pistons (touch wood). Again apologies for talking about how to do stuff we are telling you not to do
JohnD Posted October 18, 2023 Posted October 18, 2023 We all have different experiences! My attitude is that drilling the base of the piston head will weaken it, even if slightly, whereas performance piston skirts are little more than pelmets(Mary Quant would be proud!) So removing a millimetre or two from a less extreme one will make no difference. John
Escadrille Ecosse Posted October 18, 2023 Posted October 18, 2023 (edited) 43 minutes ago, JohnD said: We all have different experiences! My attitude is that drilling the base of the piston head will weaken it, even if slightly, whereas performance piston skirts are little more than pelmets(Mary Quant would be proud!) So removing a millimetre or two from a less extreme one will make no difference. John Fair enough John. But pistons don't fail at the gudgeon pin boss so it's not a weak point, like the crown or ring lands so losing a little metal here won't make the piston less reliable. And I can say that I have never had a piston or any other major engine failure in any of my engine rebuilds. And that's with big mileages and enthusiatic use. Neither does it require access to a lathe which is the case for most of us. Also I've never used anything but standard pistons in any of my engines and not sure that they are really necessary in the small Triumph engines. Certainly good for 7000rpm +. I would however say that the skirt on a piston (perpedicular to the crank) does perform an important function in reducing piston rock and wear (even if slap isn't really present), especially for a reliable engine intended to be used on the road and not rebuilt on a frequent basis. Which is one of the reasons why 'performance' pistons are a poor choice for a road engine. Edited October 18, 2023 by Escadrille Ecosse
egret Posted October 18, 2023 Author Posted October 18, 2023 A package arrived today. Lots of bits, somewhat amused (concerned?) about the bearing packaing. There's a lovely hologram on the box, but no security seal to ensure what's in the box is what it says. Both main and big end bearings have the king logo and std on them, and are also both a similar dull grey, so I'm happy they are what they claim.
JohnD Posted October 18, 2023 Posted October 18, 2023 Short skirt pistons would be the last thing I'd suggest! AND, yes, the piston crown is most robust. Even in the pic in posted on the previous page, it's intact, although the pin bearings are broken open. Each to their own - I do it on my wonky Zyto lathe!
egret Posted October 20, 2023 Author Posted October 20, 2023 Head is off, only one stud needed a stern talking to and an extension on my ring spanner to persuade it to start turning. I've started measuring and cylinder bores seem to be slightly undersized if anything (76.63-73.66 as opposed to the factory spec 73.7). This was measured with a telescopign bore gauge and calipers so it's possible I'm under-reading. But generally happy it's good. No real ovaling to note either. This progress has raised a couple of additional questions: 1- how clean should I aim to get pistons, and how to get rid of burned on carbon? 2- should I be considering valve stem oil seals? this is a question for the machine shop I suppose, but i'll be interested to hear your thoughts. 3- how thick do you think a payen head gasket will compress to? Existing gasket is about 0.65mm. This is actually not a sensitive number at 9-9.5:1 CRs I'm looking at because the range is so small and the impact is 0.01CR change for every 0.1mm of thickness (i.e. it can't be far either side of 0.65mm as the uncompressed gasket isn't much thicker than that).
JohnD Posted October 20, 2023 Posted October 20, 2023 egret, Nick said above that "you have (amazingly) an original, unmolested and relatively unworn engine." You do seem unusually blessed - it's not usual for the head to come off that easily! Gasket thickness - 0.6mm sounds tissue paper thin! I haven't gone through this exercise recently; 3mm springs to mind and that seems too thick! Piston cleaning - absolutely! get all that carbon off. An old wood chisel as a scraper, not too sharp, will help get the worst off, then wire wool. There is a domestic cleaning product "Magic Eraser", an innocuous looking white plastic foam, that is remarkable for getting baked in residue from dishes etc. without damaging the surface. You can cut it with scissors for awkward shapes. I've never used it on a piston, maybe you would like to experiment? Many sources, this is Amazon: 10Pcs/lot ERASER CLEANER MAGIC MELAMINE SPONGE CLEANING 10x6x2CM Dispatched from UK by TrisunUK : Amazon.co.uk: Grocery I've never found a need for valve stem oil seals, but up to you. John
Escadrille Ecosse Posted October 20, 2023 Posted October 20, 2023 Nice! Like John says. Give the piston crowns a clean. They don't need to be polished but you do want the lumps off. I generally use a wallpaper scraper but a blunt wood chisel will do fine. Main thing is to avoid gouging the aluminium which is why whatever you use you want to round the corners off first as that is where the problem generally lies. I don't use wire wool any more because it breaks up too easily. A normal kitchen sponge, the type with the soft abrasive on one side does along with some Mr Muscle oven cleaner and elbow grease. Like I say though you aren't looking for a mirror finish at this time. You also want to avoid getting the carbon down between the bore and the piston. Trick here is to lower the piston you are working on and put a thin smear of grease around the very top of the bore. Raise the piston to tdc, clean off the carbon, drop the piston and clean the cack off the bore. And cover any adjacent pistons. A standard cylinder head gasket is roughly 2cc volume. Close enough for what you are after. You will need to wait until after any valve replacement work has been done to work out the rest for skimming as the valve heights vary. Valve stem oil seals. Good question. Not strictly necessary as John points out - and an excellant topic for flaming on some of the forums, because like most of what we talk about on Sideways 'the factory never fitted them' - but the great John Kipping used to recommend them 40 years ago and I have followed his advice ever since without issue. Helps keep the top of the valves heads clean. No machining of the valve guides is necessay. Part number HR631 from James Paddock and others. Need to check clearance with the valve springs if twin springs are fitted and with the caps at full lift with either spring arrangement although with the standard Mk3 cam this shouldn't be an issue. You have been talking about getting the valves triple cut. Not sure I would bother at this stage of the build as you will only have to do it again when you come to do the rest of the work on the head. But if you are then you need new valves and have all the valve guides replaced. If it's a keeper then I would consider bronze guides and having the guides tapered where they intrude into the ports. Save you doing it all again later. You will also need to get the head fitted with unleaded exhaust inserts if you do this. The other and my preferred option at this stage would be to simply clean and reuse the existing 1300 head as there will be some lead memory that would keep you going for a good bit. If you go down this route clean the valves off but don't regrind the exhaust valve seats.
egret Posted October 20, 2023 Author Posted October 20, 2023 Once again lots of good info, thank you. So far I've been using old credit card to scrape, and have tried carb cleaner, brake cleaner, degreaser, engine oil to differing effects. The engine oil was simply to re-oil the area after using the solvents, but was coming off black on the rag, so doing something! I'll try a more solid scraper and lots of preparation, care, and attention. I've also got some magic sponge somewhere (bought years ago for removing stains in boat gelcoat). Valve stem oil seals will wait for now. I'm planing on using the double springs from my 1500 head so there could be clearance issues. Maybe a job the future power rebuild. As for head work I need (and have) new valves anyway, I have new guides (not bronze), and am going to have the hardened inserts put in. I figure I probably need the seats cut as part of the hardened insert install and new valves so any cost uplift to 3 angled seats is probably minimal - but I'll check! I'm now thinking about bronze valve guides. I decided against them because I could only find them on rimmers for £76+delivery which felt a bit steep. Having looked at the headwork cost breakdown it's £80 to fit and hone the guides, so having found some slightly cheaper ones from Moss, I'm now re-considering. Certainly bronze guides will be beneficial if I get around to a hotter cam. Could they be retained if gasflowing of the head was done later? If I'll need new ones after any headflow work then I'll stick with the county ones I have. I'm sticking with the new head, bigger valves and all that. I'm also of the opinion that 3 angled valve seats will make a meaningful difference at low lift, which should be really helpful so I think stands to be beneficial in isolation of any other head flowing work. Once again, this is based on my understanding of the theory. I'm happy to be corrected by the experience of others!
PeteStupps Posted October 20, 2023 Posted October 20, 2023 Nothing useful to add to John and Colin's thorough replies, except that I haven't used valve stem oil seals and don't think there is a strong reason to fit them. Each to his own, and all that. Before I did my Spitfire's full engine rebuild I had some head work done, including replacing all the valves and guides. Was hoping this would reduce its oil burning habit but it made absolutely no difference - a rebore and new pistons+rings was the only cure. There's not exactly a lot of oil swimming around in the rocker cover to burn anyway! On that subject, while the head is off make sure the rocker oil feed hole isn't blocked with sludge. Check block and head. Mine was part blocked and it's only a small hole, so the rocker was getting almost no lubrication.
PeteStupps Posted October 20, 2023 Posted October 20, 2023 By the way, here's a video of some imbecile de-coking a piston crown 1
JumpingFrog Posted October 20, 2023 Posted October 20, 2023 (edited) 1 hour ago, Escadrille Ecosse said: I don't use wire wool any more because it breaks up too easily. A normal kitchen sponge, the type with the soft abrasive on one side does along with some Mr Muscle oven cleaner and elbow grease. Like I say though you aren't looking for a mirror finish at this time. Maybe I was just unlucky, but be careful with oven cleaner (or indeed any aggressive/caustic chemicals) and precision alloy parts. You need to check it's safe for alloy and doesn't contain Sodium Hydroxide. Was cleaning an inlet manifold with some a few years ago and ended up having to get it refaced because it started to eat into the mating faces. The damage wasn't that bad but piston ring lands are a bit more critical IMO. 27 minutes ago, egret said: I'm now thinking about bronze valve guides. I decided against them because I could only find them on rimmers for £76+delivery which felt a bit steep. Having looked at the headwork cost breakdown it's £80 to fit and hone the guides, so having found some slightly cheaper ones from Moss, I'm now re-considering. Certainly bronze guides will be beneficial if I get around to a hotter cam. Could they be retained if gasflowing of the head was done later? If I'll need new ones after any headflow work then I'll stick with the county ones I have. For bronze valve guides, I got mine from Wins, just checked their site and they're under 5GBP each (although ex. VAT), quality seemed good, but still not fitted. Rimmers, I avoid unless it's something only they have. I know Chris Witor sell some very nice but expensive colsibro ones. I think for what you want now, there's nothing wrong with the iron valve guides. As for reusing, I'm not sure, depends exactly what's being done. Agree with what Pete says too, while you've got it so far apart, clean all the oil galleries out, with bottle brushes and paraffin, and then blow clean with compressed air. If you're feeling brave you can remove the distributor/oil pump drive bush, don't use a hammer on it though, it's brittle, make a puller from some threaded bar. Edited October 20, 2023 by JumpingFrog 1 1
egret Posted October 21, 2023 Author Posted October 21, 2023 I've finally found something that's worn! The clutch facing thrust washer is +005 not std. Oh and the water pump housing is corroded badly inside, the bit separating suction and discharge of the impeller is very thing and missing in one place, so is probably scrap. I think the 1500 one will be a straight swap, so it's not a big issue. Bit of block cleaning as well today, that and trying to plan the rest of the engine out process. 1
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now