Big h1c and Wh1c difference

[FUNWHEELDRIVE]

i have searched and cant find it... im assuming its just a stupid question... are they the same? just wastegate difference?

can someone inform me please
thanks

 

[dsm-onster]

There are several difference. The big h1c has no surge porting but still has the webbing int he comprssor inlet for such surge ports. The big h1c has a 54mm inducer and the wh1c has basically the same compressor wheel as the 8blade hx35 (56mm inducer). The 8 blade 7755 hx35 compressor flows 52lb/min. Thsi puts the big h1c at about 49ish lb/min based on the slightly smaller inducer. It's safe to say that it flows as much as the 20g or 50-trim compressors. The wh1c has a gated 12cm^2 housing just like the hx35 as well; and the big h1c comes with the 18cm^2 housing or 22cm^2 housing, nongated. Both have V-band clamps holding on the compressor housing. Both have turbine wheels that fit into hx35 turbine housings. But they both also have a 4 bolt pattern at the turbine backplate instead of the garrett/holset 6 bolt pattern of the later years. So if you plan on using the wh1c or big h1c, you will need to come up with 2 extra bolts and use washers with a circle segment cut out of them to safely connect it to the hx35 housings like the bolt-on housing from BEP.

The big h1c came in the 1991-1993 INTERCOOLED cummins pickups. non-intercooled has the small and baby h1c. The tell-tale difference between the big h1c and the small h1c is that the big h1c (though it has no surge ports) still have the surge port webbing at the compressor inlet. The baby h1c compressor is BOLTED onto the chra.

So . . .

wh1c: small 12cm^2 wastegated exhaust housing, 56mm inducer, vband compressor to chra
Big h1c: big 18 or 22mm^2 non wastegated exhaust housing, 54mm inducer, vband compressor to chra
Small h1c: big 18 or 22mm^2 non wastegated exhaust housing, 50-52mm inducer, vband compressor to chra
Baby h1c: big 18 or 22mm^2 non wastegated exhaust housing, 45mm inducer , bolt-on compressor to chra

 

[90tsiPA]

How did i know dsm-onster was going to answer this. haha. I guess I was too slow.

 

[FUNWHEELDRIVE]

im not surprised eaither as i see him posting in the holset threads all the time

thanks you that info is very helpful