Posted by west coast Bruce [162.158.106.21] on Saturday, June 29, 2019 at 00:04:10 :
In Reply to: WC-62/63 4BT 5:83, 4.89, 4.30? posted by Scott [172.69.170.73] on Friday, June 28, 2019 at 19:49:40 :
105hp 4bt - no intercooler .......yet
HX30 turbo - thinking about tossing in a second turbo
ARP head studs
NV4500
4.88 gears
NP 205
NWF crawl box
40 inch tires on 17 inch rims
4whl discs breaks
hydroboost
ram assist steering (takes pressure off the frame)
on the highway it will run fine at 60 miles an hour with about 5lbs of boost. Like 5 or 6hrs straight.
Crawling or on long grades it runs too hot, even with the exhaust temps at about 900 degrees. I have the stock rad recored with a 4 tube core. Going to add a pusher fan and see what that does- in most cases this seems to solve the overheating issues with crawling and the 4bt. If that does not work I will vent the hood, and perhaps add more vents to the side panels.
Driving at 40 and higher on the flats the fan never comes on.
I think 5:83 are a bit low for what you plan with the truck. 5:83 tires and 42 inch tires might work but getting them under the fenders is an issue. They fit fine under the front fenders, not so well under the rear.
I am still taking the air from under the hood - I am going for a cold air intake PDQ.
There are 3 piston compressions for the 4bt
highest is the non turbo
then the turbo
lowest is the turbo with JWAC or charge air cooler
As an aside my front axle is 1.5 inches forward from stock, the tire fits the fender arch better when it is placed there.
Balance the pistons and rods - I gather the difference in how the engine runs can be quite noticable in some cases. I will do this if I ever elect to tear into the block - it has 58 thousand miles on it and a fresh head - I am not about to tear into it again.
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