johny Posted January 5 Report Share Posted January 5 The D type overdrive was used on all models of GT6 as reportedly it never got the layer J type. The gearbox however did have changes so you would need to check its serial number as that should hopefully indicate its internals.... Link to comment Share on other sites More sharing options...
Tim Butler Posted January 5 Author Report Share Posted January 5 1 hour ago, johny said: The D type overdrive was used on all models of GT6 as reportedly it never got the layer J type. The gearbox however did have changes so you would need to check its serial number as that should hopefully indicate its internals.... I dread to even look! Still not convinced as to which block I have, it has a non round waterway at the front which makes me think it may still be mk3, but I just don't know at this stage. Probably getting too hung up on it, just need to figure out which head gasket to get! I guess a mk1, given the stud size, which typically is twice the price of the one I have. One day I'll learn to just leave things well alone to avoid opening another can of worms! Link to comment Share on other sites More sharing options...
Ian Foster Posted January 5 Report Share Posted January 5 (edited) 5 minutes ago, Tim Butler said: One day I'll learn to just leave things well alone Hi Tim Not really an option if the h/g is blowing coolant. Mk2 manifolds do come up on ebay (there are both an exhaust and a inlet manifold with carbs at present), and you might consider collecting parts for a Mk2 head swop as a future project. A mk2 head is probably the trickiest bit to find, but I'm sure they are out there. A mk1 is still a good engine. Hope you get things sorted. Ian Edited January 5 by Ian Foster Link to comment Share on other sites More sharing options...
DanMi Posted January 5 Report Share Posted January 5 (edited) mk1 block here https://www.ebay.co.uk/itm/353989878629 mk2 here https://www.youtube.com/watch?app=desktop&v=mXhRqwTrPUM note at 8.29 the curved water channel by the end cylinder not present in the early block With this channel missing in the early head, I doubt that a mk2 block would work wit a mk1 head or it could cause overheating/leaks Edited January 5 by DanMi Link to comment Share on other sites More sharing options...
Pete Lewis Posted January 5 Report Share Posted January 5 well this all seems to be MK1 engine with the 3/8 dia studs getting a Mk2 head wont match you are going to have to live with it being MK1 engine its still a good engine but will affect resale values a bit if you ever take the tunnel off we can advise on the gearbox number a picture of the carbs fitted will aid clues on just what you have Pete Link to comment Share on other sites More sharing options...
DanMi Posted January 5 Report Share Posted January 5 4 hours ago, Pete Lewis said: f you ever take the tunnel off we can advise on the gearbox number Trouble with that is the gearbox number only tells us what the gearbox case had in in it when it left the factory not what is in it today! Link to comment Share on other sites More sharing options...
johny Posted January 5 Report Share Posted January 5 Yes or it could be overstamped GR after a recon☹️ Link to comment Share on other sites More sharing options...
Tim Butler Posted January 6 Author Report Share Posted January 6 Well I'm not too hung up on originality, if it's a mk1 engine then so be it! Just got to be a rot in mind when ordering parts. It does have the curved water channel in the block that DanMi mentions, yet it has the smaller diameter head studs 🤷♂️ the head has no corresponding channel for the curved water channel but it didn't have overheating issues so I guess it works... I suppose I'll try a mk1 head gasket and see how I get on. The PO had put on a mk3 head gasket and it worked for the most part, just a small area by number 1 piston where it had failed across the chamber and water channel (probably due to low torque as that nut was very easy to undo) I'll upload a few pics of the block and carbs, and the tunnel is already off where I removed the heater matrix box to install a larger fan, so I'll add some of the gearbox. Although I'm off a night shift so some sleeping shall be had first! I already had the gearbox apart where I removed it to change the thrust bearing, so replaced some of the gearbox bearings at the same time. And I rebuilt the rear diff where the thrust washers were causing some nasty prop backlash (I don't even want to check the diff serial number!) Link to comment Share on other sites More sharing options...
68vitesse Posted January 6 Report Share Posted January 6 Didn't see it mentioned, if ordering new or reusing the head nuts and washers make sure they are hardened as there are some poor quality ones out there for sale. Have had a head nut, from one of the main suppliers, strip, when replacing the head on my 2L Mk1 Vitesse used mini flanged head nuts as mentioned on this forum. Early 2L Mk1 blocks used a different crankshaft from later ones and a different fuel pump, just the arm is different, it's position is higher up on the block. A pack of twenty mini nuts will do the head and rocker pedestals. Best of luck with the rebuild. Paul. Link to comment Share on other sites More sharing options...
Pete Lewis Posted January 6 Report Share Posted January 6 (edited) agree with using better or mini nuts the washers need examining or replace with high grade ones as these deform and that looses nut torque and the gasket failure soon follows new studs should have a slit down the head section of thread this stops hydraulic fracture when screwing the studs in the studs only need to be hand spanner nip tight in the block . quick though did the old gasket have a tab on the rear end ???? Pete Edited January 6 by Pete Lewis Link to comment Share on other sites More sharing options...
johny Posted January 6 Report Share Posted January 6 5 hours ago, Tim Butler said: I already had the gearbox apart where I removed it to change the thrust bearing, so replaced some of the gearbox bearings at the same time. And I rebuilt the rear diff where the thrust washers were causing some nasty prop backlash (I don't even want to check the diff serial number!) Yes bearings never changed in the gearbox it was just the synchro rings and some gears although ratios stayed same.... Link to comment Share on other sites More sharing options...
Tim Butler Posted January 6 Author Report Share Posted January 6 Photos of the block, cars and old HG. It's blown at the front of the block, closest to the manifolds. I'll have a look at getting the mini nuts as suggested, trying to locate some decent studs in the hope that they'll take a better torque. Still unsure whether to run with the mk3 payen gasket I've got, or buy a mk1 copper gasket... Link to comment Share on other sites More sharing options...
johny Posted January 6 Report Share Posted January 6 Surely thats a mk1 block as its got the bulges into the push rod wells that match the mk 1 gasket and which the mk2 gasket doesnt have! The PO must have thought he had a mk2 engine (logical) and used that gasket but it had no chance of working. The mk1 gaskets supplied nowadays dont seem to be copper but a composite.... Link to comment Share on other sites More sharing options...
Colin Lindsay Posted January 7 Report Share Posted January 7 This is my MK1 block from way back in the day; before I swapped it for a MK2. The oil and waterways in the block at either end don't seem to match those in Tim's photo, but they do correspond with the gasket. The underside of the head may give some comparison clues: This is the area I mean: Link to comment Share on other sites More sharing options...
Ian Foster Posted January 7 Report Share Posted January 7 (edited) Tim It's interesting to see the variations in waterways front and rear. My early Mk2 block and original head both have the long lozenge shaped slots. The head I am currently using started life as a 219015 TR6 head and was substituted, as mine was cracked between the seats on #6 cylinder which is apparently a common problem. It was gas flowed and skimmed, but when I removed it after a few years use, I noticed that it had just a round hole at the rear. I went for a further skim and had the water passage at the rear opened out to match the the block (as original). It is possible that later blocks changed to just a round hole as per the TR6 head. Perhaps someone with a Mk3 could confirm. Ian Edited January 7 by Ian Foster Link to comment Share on other sites More sharing options...
johny Posted January 7 Report Share Posted January 7 Do all the blocks have the bulges into the pushrod chambers Ian and its just the mk 1 and 2 head gaskets that are different in this area? Link to comment Share on other sites More sharing options...
dougbgt6 Posted January 7 Report Share Posted January 7 Well, Tim’s block ain’t recessed, but I wonder if PO fitted a gasket for a recessed block? That wouldn’t last too long! Was there a tab on the back of the old gasket? Doug Link to comment Share on other sites More sharing options...
johny Posted January 7 Report Share Posted January 7 (edited) Gasket doesnt look recessed in photo above just a normal mk2 fitted to a mk1 engine which wouldnt help its correct location🤔 Edited January 7 by johny Link to comment Share on other sites More sharing options...
Pete Lewis Posted January 7 Report Share Posted January 7 (edited) well at least the carbs are CDS simple no frills with cold satrt choke on the front unit tubed to the rear one thats good better studs unlikely that that is possible , its the nuts and washers are the weak link here not the studs the 42-46lbft is quite adequate for the 3/8 studs the washers deforming is the main snag and never use std 3/8 nuts they wont take more than 31lbft the orig Nuts are oil quenched black finish . mini flanged nuts are the way to progress but bear in ming knurled washer faces can absorb tightening torque Pete Edited January 7 by Pete Lewis added Nuts !! Link to comment Share on other sites More sharing options...
dougbgt6 Posted January 7 Report Share Posted January 7 1 hour ago, johny said: Gasket doesnt look recessed in photo above You can see a gasket? 🤔 Doug Link to comment Share on other sites More sharing options...
Tim Butler Posted January 7 Author Report Share Posted January 7 So evidently the block remains a bit of a conundrum, but we'll spotted on the bulge front as the images of HGs show the mk1 with a bulge and the others without. The old HG isn't a recessed style, but it's definately for a latter mk as the bolt holes are larger (which as pointed out wouldn't help with it's positioning. I'll fit a mk1 gasket as the curved waterways don't connect to the head anywhere so it shouldn't affect cooling. And I'll get some new short studs (although Rimmers photos show them as silver rather than black) and go for the mini nuts. I considered asking Chris Wittor for an opinion as I was surprised to see he is based near me, but figured that may be a bit too cheeky. Going into rest days now, so hopefully I'll get chance to clean up the head and refit the valves. Try and brave the cold to clean up the block (I really need a garage!), then it'll be time to refit... Want to try and get it back on the road as it's spent more time in pieces than driveable since I bought it! Link to comment Share on other sites More sharing options...
johny Posted January 7 Report Share Posted January 7 Whats the issue then Tim? I thought its clear a complete mk1 engine has been fitted and the PO just thought as he had a mk3 GT6 it would need the later gasket.... Link to comment Share on other sites More sharing options...
johny Posted January 7 Report Share Posted January 7 34 minutes ago, dougbgt6 said: You can see a gasket? 🤔 Doug Here we are, what do you think Doug? Link to comment Share on other sites More sharing options...
dougbgt6 Posted January 7 Report Share Posted January 7 (edited) I thought that’s the marks where the gasket woz? Oh, well. Optician says I got cataracts coming. db Edited January 7 by dougbgt6 1 Link to comment Share on other sites More sharing options...
Pete Lewis Posted January 7 Report Share Posted January 7 that gasket has let go due to lost clamping ....soft washers and lost torque its the nuts that will be black not the studs ( sorry i left 'nuts' out ) Pete Link to comment Share on other sites More sharing options...
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