I want to build a 1600 turbo engine I have two choices to engine case H (1500cc)engine and AS (1600cc)engine
What is the difference and whether you act on performance if you use H engine case.
H-block is no indication that the AS41 and AS-block is marked AS41 indicated, should know that there is a difference in weight is not a block but that's identical 10,2kg (22.48715lbs)
I wanted to build H-block me but a friend his mind.
Addendum to Newtons first law:
zero vehicles on jackstands, square gets a fresh 090 and 1911, cabby gets a blower.
EZ3.6 Vanagon after that.(mounted, needs everything finished) then Creamsicle.
H0 and early H1 cases are cast from a decent alloy (identical to F0/F1 1300) but they're single-relief, small-oil-passage and not recommended for any high performance application. For a few years they were the best available case, but that was ~45 years ago...ANY dual-relief case is better. Late production H1 cases can be dual-relief, essentially identical to dualport cases of the same vintage other than the size of the cooler mounting hardware and the length of the four inner-upper head studs - if you have one of those, it's worth looking at but if I understand you correctly your "H" case has no AS41 markings which indicates that it's of earlier vintage...is it single or dual relief?
H5 (and the bus B5 variant) were used in VW's first attempts at making US emissions-compliant engines, where lean mixtures were causing elevated operating temperatures. They decided to try a less-dense alloy to improve heat transfer through the case - turned out to be too weak...more prone to cracking, warping, and pulled studs...the experiment ended after two years. There are very few of these left that can be considered usable, even for a stock 1500SP, and even then only after investing a bunch in restorative/corrective machinework...and they still may fail. The ONLY reason to use one would be for a numbers-matching trailer queen restoration.
