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Drawthough with RHB5


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I have an IHI RHB5 out of what I think is a late 80's Loyale. The turbo spec # is VF48710.

I would like to use this turbo in a custom application doing a drawthough on a carburetor(MGB with a single 1 3/4" SU). I have read that in order to use a turbo in a drawthrough setup that the turbo must have carbon seals in order to keep the oil from being sucked out of the turbo. Can anybody advise me on this matter? Are carbon seals even avaliable for this turbocharger?

Thanks,

Robert

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umm two things why are you going to make a turbo'ed carbed car? fuel injection will work SOO much better. and why use the RHB5? they're better turbos out there.

 

To properly FI this car will cost nearly $4K. It would require changing the head, rocker assembly, fabricating an intake manifold, wiring harness, stand alone management system, fuel return lines, gas tank modification, and gobs of patience- FI was not an option in 1969.

 

The engine is a 1798cc pushrod L4 cylinder(94hp,110lbs torque), if not the RHB5, what would you suggest for a quick spooling turbo- T28?

I purchased the IHI from ebay for $36 shipped- all it needed was to be rebuilt, good housings, impellers, and waste gate.

 

I would like to use the IHI as I already have the parts I need to set it up. Will the RHB5 work in a drawthrough application?

Thanks

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4k to inject your car???? wtf

what are you doing it the hard factory parts way or something?

betcha i could figure out a better cheaper solution :)

 

just a hunch ....

:)

 

Thats to do it properly. I could be done for less but with less success. The problem with the MG is its siamesed intake ports. With a firing order of 1,3,4,2 and cylinders 1&2 sharing a port along with 3&4. What you get is a period of overlap where cylinders 1 and 2 are drawing air at the same time, this causes extra fuel to be required during this period of overlap, so a batch fire or throttle body will not work. You WILL get a lean condition on cyls 2 and 4 and rich condition on 1 and 3. I saw a guy who built a custom tuned port intake manifold and had exactly that problem- power was gone by 3000 rpms.

For proper FI on these engine you have to change over to a crossflow head which alone costs over $2k. Then you need manifolds, wiring, rocker assembly, computer, etc.

 

There are no factory FI, turbo, or supercharger parts. MG never made that an option. The company produced cars from about 1926ish to 1980 when the origional MG company went out of business and never fuel injected a car. It's British, they are not known for great innovations in street cars.

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The best turbo to use for a draw-through system is the one found on the 80's Chrysler 2.2L products. New Yorker, Datona, etc. This is a Garrett/AiResearch T3 and it has the seals you need and a nice machined area on the compressor inlet to bolt up a side draft carb.

 

The RHB5 is not a good choice for a drawthrough, it is too small (drawthroughs need a larger compressor than a blowthrough system) and it doesn't have the right seals. It would blow smoke all over the place. You could put a small throttlebody downstream of the compressor that uses the same linkage as your throttle on the carb, and this will solve the smoking problem. This technique will allow you to use any turbo in a drawthrough setup. You still can't use a BOV in this system, making your turbo lag a problem between shifts.

 

I have an air-cooled VW that uses a stock single barrel carb and an RHB5 in a blow-through setup. It works VERY well. Let me know if you want specifics.

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soo... if yoiu run say a megasquirt box

in alternating firing

you can wire injectors 1 and 3 together and then 2 and 4 together

then would that not take care fo your problem?

 

 

or as mr balls stated.

you could go with the draw thru turbo dodge setup

but you will still need either a reflashed dodge ecu or some kind of aftermarket or do it yourself injection controller setup

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soo... if yoiu run say a megasquirt box

in alternating firing

you can wire injectors 1 and 3 together and then 2 and 4 together

then would that not take care fo your problem?

 

 

or as mr balls stated.

you could go with the draw thru turbo dodge setup

but you will still need either a reflashed dodge ecu or some kind of aftermarket or do it yourself injection controller setup

 

Another option could be Megasquirt with throttle body injection

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  • 2 weeks later...

My concern is exactly that, sucking oil past the seals when manifold vacuum is present- basicaly the turbo compressor will become part of the manifold. I have debated the throttle body after the turbo and carb to control airflow. I can pick up a thottle body for cheap off of ebay.

 

Here is the other thing for those of you talking about FI. I am cheap, that is why I am still doing a carb setup. The used RHB5 cost me $36. I have a bypass valve I paid $20 for shipped(yeah it looks good and works). I found a full turbo rebuild kit for 60 bucks ($120 from turbo city) from eBay. I will make my own manifolds- mainly because nobody else does.

 

Thanks for the suggestions.

--Robert

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Rh,

The B1800 engine is a stout unit (you must have

the model with the 5 main bearing config as you say

single Stromberg)

 

I put a Roots super charger (boost pressure 7 psi.)

on a TR 3 once.

 

These have basicly the same "tractor engine" derivitive.

 

The engine ran great for about 15 seconds.

The top ring on each piston was pulverized into ant

sized chuncks.

 

Just a thought.

 

 

I had several "B's" still have the driveline from a 69

sitting in the basement.

I am partial to TR's but MG's are kewl to.

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