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Discussion Starter · #42 ·
Decided to go belt drive on the steering/brake pump, added 2 more belt idlers, Tried Perfection Clutch aluminum slave and master,
installed HIEM joint on clutch linkage. Installing new fuel tank with custom sender and fuel fittings for tank tubes
 

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You have the HX35W on the engine but an HX30W is considerable smaller since you mentioned clearance issues. As Dougal pointed out, this will be lazy in the power band. A 4 cylinder just can't make enough exhaust to boost it properly. And HX30W turbos are readily available, just not in the used market.
 

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Discussion Starter · #47 ·
I think you are basing your opinion on a 3.9 and not a 4.5, but there are readers that have been running a HX35W on a 3.9 ( 4BT) ,
with reasonable success. There are a few variables between every setup.
 

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No, they think they were comparable until they change to an HX30W. The HX35W is slower to boost and runs much higher EGT. It's boost is mainly in the upper RPM range and not where you normally want to run it. The only 4bt that came with an HX35W was the 250 HP marine engine which had a water cooled turbo. The HX35W has a 12cm2 turbine housing where the HX30W is half as big at 6cm2. On the compressor side the HX35W has a 54-56mm inducer where an HX30W ranged from 40-46mm. So you'd have a bigger compressor wheel to spin and a twice as big exhaust housing to fill and only 2/3 the possible exhaust volume to fill it. Doesn't take a rocket scientist to see that isn't going to work very well.
 

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The 250 HP 4bt ran a 3000 RPM governor although the factory said that speed should be limited to no more than 5 minutes per hour. You sort of know how many people paid any attention to that. Lot of difference in cruising in the 2400 RPM range and 1800 RPM for road use. Those marine engines also ran a water cooled aftercooler to help keep engine temp in check. When you have an unlimited supply of cool water you can keep the heat low.
 

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Discussion Starter · #52 ·
The 250 HP 4bt ran a 3000 RPM governor although the factory said that speed should be limited to no more than 5 minutes per hour. You sort of know how many people paid any attention to that. Lot of difference in cruising in the 2400 RPM range and 1800 RPM for road use. Those marine engines also ran a water cooled aftercooler to help keep engine temp in check. When you have an unlimited supply of cool water you can keep the heat low.
\Ya, if your cooling with RAW water ;)
 
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