ALH/BHW Hybrid: Success!

dieseldonato

Veteran Member
Joined
Mar 10, 2023
Location
Us
TDI
2001 jetta
If I'm getting too far off the rails here I'll start another thread, related ro this subject, but I think it pertains with the current discussion. is there a issue with breaking the smaller 48 (?)mm crank pin, or is it just a rod strength issue? I see there are some H beam rods available for the alh platform, surely for a 200 ish hp build they would suffice over finding another engine and building a hybrid? I'm also assuming 180-200hp is somewhat a std build from what use been reading.
 

jmodge

Veteran Member
Joined
Jun 18, 2015
Location
Greenville, MI
TDI
2001 alh Jetta, RC2 w/.205's 5speed daily summer commuter and 2000 alh Jetta 5spd swap, 2" lift, hitch, stage 3 TDtuning w/.216's winter cruiser, 1996 Tacoma ALh
Cutting the crank is easy...getting rods 1.5mm shorter, not so much. More stroke means more displacement. I suspect boost and solid after-cooling will deliver that additional air mass easier.

BEW heads have their valves sunk further into the head and have no pockets in the pistons to clear the usual ARL/BHW/ALH stick-out. BEW head and BEW pistons are the mated pair of bits.

Douglas
Or pistons with the pins closer to the deck
 

jmodge

Veteran Member
Joined
Jun 18, 2015
Location
Greenville, MI
TDI
2001 alh Jetta, RC2 w/.205's 5speed daily summer commuter and 2000 alh Jetta 5spd swap, 2" lift, hitch, stage 3 TDtuning w/.216's winter cruiser, 1996 Tacoma ALh
Have to disagree; mains are the same across ALH/BEW/ARL/BHW...rod journals are either 48 or 51mm. As I hunt up an ARL/ASZ crank for its 51mm rod journals... :) Rod strength goes something like ALH>BEW>ARL>BHW. For stockers anyway... LOL

Douglas
So the BEW is the only one with larger Rod journals? BHW same rod journal as ALH, just stronger rods and larger bore/stronger pistons/ lower cr?
 

jmodge

Veteran Member
Joined
Jun 18, 2015
Location
Greenville, MI
TDI
2001 alh Jetta, RC2 w/.205's 5speed daily summer commuter and 2000 alh Jetta 5spd swap, 2" lift, hitch, stage 3 TDtuning w/.216's winter cruiser, 1996 Tacoma ALh
If I'm getting too far off the rails here I'll start another thread, related ro this subject, but I think it pertains with the current discussion. is there a issue with breaking the smaller 48 (?)mm crank pin, or is it just a rod strength issue? I see there are some H beam rods available for the alh platform, surely for a 200 ish hp build they would suffice over finding another engine and building a hybrid? I'm also assuming 180-200hp is somewhat a std build from what use been reading.
Rod strength and oil squirters / piston cooling/strength. I think the cranks all hold up well, from second hand info
 

PakProtector

Veteran Member
Joined
Jan 5, 2014
Location
AnnArbor, MI
TDI
Mk.4's and the Cummins
BHW has 51mm crank journals. ALH, BEW and BRM have 48mm cranks. I think the common rails went back to 51mm...CJAA and the like. As far as I see it, the larger bearing dia is for load only. Larger means more area, and the larger dia gives higher bearing speed( which helps load increase as well ). Not that the trans will be happy with a rod-bender tune...LOL

This at the rod journals. Have never seen any indication the mains are different.

Douglas
 
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