Greensand handles the heat pretty well but tends to flake off in the combustion chamber - scoring the cylinder walls.How were you thinking to cast these? Lost PLA in dry or greensand or ?
This is not a trade I've exercised either, but I've read a lot....Greensand handles the heat pretty well but tends to flake off in the combustion chamber - scoring the cylinder walls.
This is a trade I haven't really given a lot of thought. I really like lost wax but unless it is needed due to complexity using sand (K-bond) with CO2 set cores for the ports would be the quickest. The stock heads look to be done with a 6 part mold (top,bottom + 4 sides) This is easy enough to duplicate in sand but the 45 degree port flanges and curved ports kind of messes up that option. A built up multi-piece lost wax might be needed.
Thinking about using 3D printing for the pattern to build the silicone wax molds.
Feeding always seems to be the variable hardest to get right the first time. Alloy for this project is a whole project of it's own.Feeding the fins will be the trick,
Interesting idea - will think about it.Why not design the head for a weld-on port? <> >> Exhaust might be a bit of a challenge, SS is more suitable than an alu pipe.
Having the pipe angled slightly so that the incoming air is favouring the outside of the bend into the valve opening and up towards the centre of the bore should yield a better flow as well. It is usually beneficial to have a slight twist (off-set of the port direction) to induce some swirling of the incoming charge.
TiPi, did You finally found, how to rework 49M for use it as SE33? I'll test it with PSRU. Now testing VW 1930cc stroker.This is a table comparing some of the industrial engines that have been used or proposed for aircraft use over the last 10 or so years.
If you compare this data to "proper" aircraft direct-drive engines, the achievable power is around 40hp/lt and maybe 43hp/lt with everything optimised. The power/displacement is normalised to 3,600rpm and based on max power (not all manufacturers have max cont power advertised).
View attachment 100003
Aiming for 43hp/lt (35hp out of the Briggs 49) is already at the high-end. A set of new heads optimised for flow at the lower rpm might improve the output but I'm not sure by how much and if it is worth the effort. It would be very nice to try.
Put the EX port to the out side and and the IN port towards the V and make it universal (heads up or down, pusher or tractor, flywheel or PTO drive).Realized to day that I put the heads on the wrong sides. On the vertical engine the exhaust is on the PTO side, not the flywheel side.
I had to fabricate the shims for a Jag when I was sold a basket case when I was 15. It was the year I began learning to machine. In this case, a lathe, a heat treating oven, a surface grinder, and hand polishing techniques.recall the helpful advice in a Jaguar repair manual: "Remember that if factory replacement valve shims for the 3.8 liter engine cannot be found, the shims for a Lotus Cortina are also suitable.” Great! Pep Boys is sure to have those.
Our most profitable machine at work makes $30,000 per day. It is 30 years old. We can usually get parts, but they tend to take weeks to come. I make or improvise a lot of parts for it...I had to fabricate the shims for a Jag when I was sold a basket case when I was 15. It was the year I began learning to machine. In this case, a lathe, a heat treating oven, a surface grinder, and hand polishing techniques.
It worked, and I was able to part.out the basket case with engine for enough profit to help fund my first airplane...a Pacer, for 4200.
Way off topic but....I think no one who has ever adjusted valves on a Jag, Alfa, Fiat, or Lotus and went to a Pep Boy’s and asked for parts for those.
I've seen that on a small industrial engine on a cement mixer. Flat head, either grind the stems or the shimless lifters...Way off topic but....
The weirdest valve adjustment I ever had to make was on a DB-5 that needed a valve regrind. Probably part of the reason it needed a valve freshening is that there is NO way to adjust the valve lash other than grinding the stems after assembling the head and measuring the lash - if there is any after the valve work.
IMHO 007 was lucky to have survived that ride.
Sorry for any miscommunication--my comment was meant as a wry observation, not advice that those needing obscure foreign parts seek them at Pep Boys. It's just that, from my vantage point in the USA, the idea that if I couldn't find a Jaguar valve shim that I could easily find a Lotus Cortina valve shim was funny. Probably makes good sense in England, but in the US it is like saying "if you need a 1/4" x 1 3/8" cotter pin and don't have one, remember that the micro retainer pin on the lunar module landing foot pad can be easily used in a pinch."I think no one who has ever adjusted valves on a Jag, Alfa, Fiat, or Lotus and went to a Pep Boy’s and asked for parts for those.
Universal would be ideal - but more work than I care to take on in the near future.Put the EX port to the out side and and the IN port towards the V and make it universal (heads up or down, pusher or tractor, flywheel or PTO drive).