Awesome Powdercoat (great name) in the US makes the repros. I can’t remember who in the UK imports them. Mine cost about £35.
They do sound worthwhile, seems approx 5 degree temp reduction when using one, which can only be good. Makes sense increasing the air flow intake across the heads too. Seems a simple mod too.
If you're after a robust slogger, I'd suggest you use a stock cam, rather than anything fancy (and likely inferior).
I think the type 3 under tins are not useful on a bus because the air flow round the tins under the engine is different. There should be little rectangular deflectors clipped on the cylinder fixing studs just below the cylinders. The pistons are cooled by the oil directly splashing up onto them. And the oil temperature on my engine sits maybe 20 degrees below the temperature sensor fitted in the boss on my Autolinea heads from 6 years ago. The cooling of the heads is mostly by air but the pistons are removing heat, oil comes along pushrod tubes to the head along with running a rich mixture which absorbs some heat. The difference between a hot running engine and a cooler one may be down to a choice of the idle jet size allowing the engine to cool off quicker at low throttle setting. At higher RPM there is a lot of cooling air, at low RPM there is less air cooling but the heat from high speed running is still flowing from the combustion chamber. So my cylinder heads are say 120 degrees oil about 100 at 65MPH. Then I leave the motorway and the heads heat up to 130 degrees after about half a mile of slow driving and the oil temperature creeps up a bit. After 3 miles of driving or 20-30 minutes down Hamble Lane the oil is cooling to 95 degrees and the heads are back to 110 degrees. Showing its not the high speed thrash that damages but the cuppa in the motorway services or the queue to get off the M27.
We’ve been looking at 1776cc specs and put together some initial thoughts. Appreciate some feedback, either positive or negative! Thanks. OEM eight dowel German crank with welded counter-weights with a mated flywheel. Gene Berg steel pulley. Balanced connecting rods and pistons. Camshaft??? Possibly Web Cam 86 (?) with 7.8 compression ratio, single Solex carburetor / Engle W100 & 7.9 to 8 compression ratio. HD springs - ported / polishes. 040 head with stock sized valves. Solid rocker shafts. CB Performance lightweight lifters. carburettors?????
Forget the fancy crank and counterweights (you won't be revving it), use the existing heads (if they're ok) with a 3-angle job and new valves, use the existing cam (not much different to an Engle 100), stock rockers, springs and generally stock everything A pair of boggo Weber ICTs, or Dellortos (36 or 40s) if the budget's big enough.
I was hoping someone would say something like this! We have been debating things at this end and I just want to keep it as stock as possible - friend is like a kid in a candy shop!!!!
Seriously, don't go over top You want a plain old slogger, and stock parts are generally more robust than fancy aftermarket stuff.
Half of this stuff will make little noticable difference in a van engine, IMHO. Bit of porting/polishing and valve job gives you a few free horsepower, twin carbs and a reasonably free-flowing exhaust will let the engine breath properly. That's it.
69mm c/w crank stock rods 90.5 pistons/cylinders Engle 110 cam or similar grind 8 - 8:5:1 cr DP heads w/clean up of ports and 3 angle valve job 36 dellorto carbs good quality exhaust - CSP?
I stuck a 100 in mine. 40 dells would be fine as well, choked right down. Any decent exhaust, really. I've got a JK stainless.