Sovuf

Hello guys, I have two Holset H2C turbos in my garage, and I figured, I have them, why not use them? It would be really cool to run a twin turbo setup but that may be trouble waiting to happen. I dont know anything about turbos, just basic principles on how they work, etc. What do I have to do to get these bad boys running on my IROC? It has a 350 carburated engine. The compression is 12-1 which is way too high for a turbo, but I have a different set of heads I can use which will bring it to about 9-1. Anyone used similar turbos?

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thunder85

isn't an h2c a bit large for a twin turbo setup?

__________________
The only difference between genius and stupidity is that genius has its limits - Albert Einstein

gibsongod716

for twins oh yes its way to big that's why they're on single turbo diesels

junkcltr

Others have used two H2C turbos on a 350ci. What is the compressor wheel inducer diameter? What are the numbers on the turbine? There should be a number like 12, 16, 19, 22, 25. This will determine if you can use them in a twin setup. Got any pics of them?

thunder85

where would the numbers be? i have one i'm using in a single turbo build and the housing has no numbers on it i can find.

__________________
The only difference between genius and stupidity is that genius has its limits - Albert Einstein

junkcltr

For the compressor inducer wheel diameter you will have to cut a piece of construction paper just wide enough to fit into the inducer inlet. See picture #1 on the left of this link:
http://cgi.ebay.com/ebaymotors/CUMMI...Q5fAccessories

For the turbine numbers look at picture #3 down on the right at the link above. That turbine is marked "21".

thunder85

wow... i wish my turbine housing looked that good. that number is no longer there. i'm in the process of rebuilding it so i have it all apart.. new bearings and seals in the chra and working on cleaning up and smoothing the inlet on the turbine housing. guess i'll have to strap it in and hope its one of the good ones.

__________________
The only difference between genius and stupidity is that genius has its limits - Albert Einstein

junkcltr

More than likely it is a 19 or a 21. Either will spool fine on a stock or mild 350ci? How much BHP are you looking for?

What distributor did you get the piston seals and bearings from? Or did you buy an ebay kit?

Did you make the comp. and exh. wheels before taking it apart?
What is the torque spec. Holset uses for the comp. wheel nut on the H2C?

thunder85

I am following the h2 series manual i downloaded (pdf). A friend of mine suggested a distributer and i asked and they hooked me up. all the parts look exactly like what i'm removing, the only thing is it didn't come with a new splash shield and the manual says to replace that.

i marked the comp wheel as the exhaust one doesn't need to come off. check out the following link for manuals and information on the holset turbo line:

http://www.holset.co.uk/mainsite/fil...%20manuals.php

__________________
The only difference between genius and stupidity is that genius has its limits - Albert Einstein

junkcltr

I am guessing you meant "heat shield" and not "splash shield". When I rebuild them I just install what they need. It is usually just new journal bearings and piston rings. Sometimes a new thrust bearing is needed. If the heat shield is good I re-use it. Keep in mind I am not a "professional turbo rebuild facility".

The biggest thing is attention to detail and cleanliness. Use picks to get the parts perfectly clean and inspect everything very closely for wear and cracks. If a wheel hit a housing I would also check the exhaust wheel for out of balance (bent).

Sovuf

Hey guys, the turbos I have are both marked "22"

The inside diameter of the intake is roughly 3 3/8.
The side that goes to the manifold (or intercooler) is about 2 1/4

junkcltr

The measurement sounds wrong for a compressor wheel. Take a piece of construction paper and cut it so that it just fits down the inducer hole and touches the tips of the compressor wheel. Also do this for the exhaust wheel. Post the measurements for each wheel.
The comp. inducer wheel should be in the 2" to 2 3/8" range.