Std crank, std size lightweight rods (VW 2L ones weigh a ton), fingers crossed? If I were doing it again I think it might be wise to fill in the case before machining, but it's too late now and it's a very mild spec other than the size. Should be ok, if it's not I'll start again and build a 78 x 104 on a welded case.
A big difference between T1 and T4 is a T4 already has what to a T1 are at least halfway to stroker pistons. The one's I bought (a bit randomly) have produced 3.5mm deck height on the undecked case so the piston pin must be even nearer the top. Calc for 7.5:1 says 63cc chambers which is easily achievable from the approx 50cc they are. If we decked the case to get 1.5mm we'd need 80cc heads to get the CR down. Not happening. The heads may end up very slighly hemi cut opposite the spark plug. and deja vu for me at this point if you remember my 1955 T1... Hemi heads, similar deck height, std cam... Masses of torque at low revs but started to run out of puff at about 3,000rpm IIRC. Improved greatly, but not enough, with mild ratio rockers - 3,000 turned into 4,000 rpm. But it had 6.something CR (or was it 5.something!) and small valves and ICT's. T4 already has ratio rockers as standard, I'll have worked heads with bigger valves. Not to mention - look down a twisty turny T1 inlet you can just about see the valve. Now look at a T4 - it's a bit straight tube to throw petrol down. A certain well renowned T4 engine builder, according to a chap I met at the weekend, is reported to have opined sneeringly that 71 x 104 is for boy racers. lol
Well... they're 1700 39.3 heads with 42mm stainless valves and work to the seats and valves. Tried to get two 41mm 1800 heads to no avail.
Pratting about with heat exchangers... I sourced a pair of almost new repro skin and flange donors and set about the flange on the worst one first, so if it went a bit awry I'd have some hope of matching it with the easier one. The first 10-15 mm of one pipe was particularly bad so it made sense to me to replace flange and pipes as one. The repro pipes are thicker stuff and slightly larger diameter inside too - 1-1.5mm bigger? The join will end up inside the skin so it had to be done before I can mock it up on the engine - I don't want to be overly held up at that stage. The skin was originally fitted to the larger pipes so it should all work out. The other one's pipes were both in much better condition so I removed the flange, cleaned it up forgetting the old pipes were smaller and now have a big gap to bridge on one pipe. I found out in time and made the other a tight fit. This one gets welded inside the flange so I can mock it up, tack the other side then fully weld while the skin's on. Skins: Original skins, the two halves were mostly just crimped together. The repro have a weld each side of each downpipe as well - presumably to stop them rattling as there was nothing inside them. Makes getting them off a bit messy. Looks like the only paint inside is what blew in while the finished heat exchanger got painted. These are now coated in phosphoric acid, we shall see how they come out later... Oil does soak into rust rather nicely and protects it from the acid! I've degreased as best I can first.
Here's the top one in the last picture - going well It works quicker the deeper it's pooled so have to kep wetting the sides.
Unlike a lot of rust treatments I've tried that quickly form a black skin over the surface of the rust, sealing any deeper rust behind to carry on it's merry job (imo) the pure acid just keeps eating away at the rust.
I use a blow torch on the corroded bits before dunking them for a day It burns out the oil and other crap and allows the acid to do its job I bought some acid a while ago that was more expensive but claimed to have a corrosion inhibiter mixed in with it Corrosion inhibiters my arse parts flashed over with surface rust in a few days. Straight phosphoric for me from now on
'course after washing the acid off it goes rusty immediately so I ended up painting with k-rust as well after all. and a couple of coats of rusoleum "galvanising" paint. I have no idea if this is any good for this purpose, but paint is paint and if didn't have any before so it must be better than that. I've only painted the insides as the outsides will get a battering when I put them back together. Boring, boring, boring...
You and others may find it boring but its this sort of thing that perks my pecker Other classic forums are full of kitchen chemistry on how to save certain parts We are lucky in the dub world for the spares supply that is available even if all of it need tweaking Fingers crossed you get out of that workshop and into the real world soon I dont want you turning into me
I was worried about him so I asked a local psychiatrist to pop in and have a gentle chat...... Not good news I'm afraid. According to the report from the shrink, Steve's been living in the windowless garage so long that he's become institutionalised and probably wouldn't be able to cope with normal life outside of his four walls anymore.
Thats ok Sounds like normal steve Hes welcome here anytime as mrs para says hes no bother he keeps his own space Shes not seen him when he cant find his book lol
Head up north bright is somthing people pray for at this time of year The solitude is cheap and plenty though
