Gearing Question

[Piledriver]

Turning ~4500 RPM all day long probably won't do much for your fuel efficiency...
...but for folks with Busses/Vanagons it's simply life.

How annoying it is may have more to do with your sound deadening than anything else.

[britegreenVWSB]

@Piledriver - The sound of 4500 rpm droning in my ears is not a problem. I have a LOUD stereo. MY concern is: Will the sucker overheat driving down the freeway at 60-70 mph? For induction I'm using CB CFI (the old dash mounted controller style; I know, it's "old" but so are 48 IDA's... hehe) and a Compufire ignition triggered by a 009. One nice thing - I guess - about the CB CFI is that I have manual control. If the thing is overheating I can try to enrichen the mixture while driving to see if it cools down. I dunno....

[Piledriver]

The only reason it would potentially overheat (assuming all tin and seals are in place) is lack of vacuum advance, basically you are very retarded at cruise without it.
Of course if you lack ported vacuum, and have a big cam, it's kinda hard to use it anyway, programmable ignition w/MAP sensor of some sort is probably the best option.

You CAN run vac advance off manifold vacuum, but you may want a throttle actuated vacuum switch to kill it at idle.
(if you have a big cam, it may not matter)

Your oil temps will tend to run higher at higher RPM, but at least you are not pushing a shed.
One possible thing that cam make that worse is if you are running a heavy oil and a big pump, and bypassing the oil cooler at 4500 RPM due to the stock oil cooling system.
The main thing that drivesss head temps is load, and again, you aren't pushing a shed.

[56speedster]

Just noticed the warning Pile - that's hilarious!

[Piledriver]

Yeah, DIY electroconvulsive therapy using direct implant electrodes is not suggested.

[Bruce2]

One possible thing that cam make that worse is if you are running a heavy oil and a big pump, and bypassing the oil cooler at 4500 RPM due to the stock oil cooling system.

I don't think it needs thick oil or a big pump. At 4500 rpm, any oil in any pump is going to generate enough pressure to bypass the oil cooler. So, he will run super high oil temps.

[Piledriver]

One possible thing that cam make that worse is if you are running a heavy oil and a big pump, and bypassing the oil cooler at 4500 RPM due to the stock oil cooling system.

I don't think it needs thick oil or a big pump. At 4500 rpm, any oil in any pump is going to generate enough pressure to bypass the oil cooler. So, he will run super high oil temps.

...Or run full flow filtering and cooling as has been recommended since dirt was new.
You are absolutely correct, it only takes a lack of attention to little details...

My motor with a stock pump and spings/clearances etc oddly stayed just under 42 psi at fast cruise in the 73 Bus for some reason...
...Even with 20W50 GTX tar in it back in the day when it was still good oil, and spinning at ~4500 RPM.
(just about max airflow for the T4 fan there, too, ~1700 CFM @4600 RPM IIRC)

I could hammer along in 100+ degree weather keeping up with traffic fine and still didn't cook my oil, almost never cleared 220F.
Admittedly that was a 1.7L T4, but he is building a (primarily) race car, so full flow oiling might not be an unreasonable suggestion.

[britegreenVWSB]

The engine does have full flow oiling, but I don't have a remote cooler at this time. Something to think about if there is money in budget to do it.

[Piledriver]

The "remote full flow cooler" can be a T1 cooler in the doghouse if need be, better than factory effective esp using an oil tstat, and cheap/easy to do.
(Many T4 upright conversions do this, usually with a thicker T4 cooler, but I'm personally dubious size matters much in this case as the airflow is ~the same)

The factory doghouse mount can be modded for rear side oil inlets (front is front) , through the rear of the tin.
only a block side cooler bypass is needed.

This setup works very well, here at least.