Comments on intercoolers

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From Paul Scherek:

Hi all,
I would like to get a few opinions please as to the value of fitting an intercooler. I am interested in the effect on power and economy, plus any opinions as to the effect upon engine life long term. My engine has done 300,000 k's. Would this be considered too elderly to accept a performance boost?
There seem to be two options - air to air, and air to water. I would be interested to know what forum members think of each type please.
Thanks everyone,
Cheers,
Paul (Oka 059)
May 31, 2010 at 7:02 PM Flag Quote & Reply

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From David Hallandal:

Paul
I am going down the water to air intercooler option from PWR, and will have some performance specs hopefully by the end of the year on a dyno. We will dyno the truck with: No intercooler and With Intercooler on standard air box and With and without intercooler with an airbox upgrade. The airbox is a big restrictor on an OKA and hope to have full figures with all options soon. See my home page for the airbox upgrade we have done.
David Hallandal
May 31, 2010 at 7:05 PM Flag Quote & Reply

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From Peter_n_Margaret:

Hi Paul.
An intercooler will not improve performance on its own, it simply cools the intake air allowing more oxygen to be fed into the combustion chamber.
That LETS you feed in more fuel IF YOU WANT TO, than you could otherwise.
We intercooled OKA196 (air cooled) after an engine rebuild. We adjusted the fuel pump to allow more fuel and got about 15% more power (seat-of-pants, not dyno). The extra power is only there if you plant your foot.
There did not seem to be any economy change that I could notice.
That was all about 140,000km ago.
It is a strong engine and it will take it (unless it is stuffed) and it was originally designed to be intercooled.
Tim Forsyth (Qld) fitted a watercooled intercooler and a different turbo to his OKA (his write-up is on his page). I have driven his and the torque band starts MUCH earlier than mine. A really dramatic and useful change.
Cheers,
Peter
May 31, 2010 at 7:06 PM Flag Quote & Reply

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From Tim Forsyth:

Hi Paul,
As Peter said have a look at my story about the power upgrade. There is a lot of info there which will answer plenty of questions for you.
In my opinion any performance upgrade to the Phaser has to start with replacing the turbo with a waste gate version. Basicaly this type of turbo is introducing full boost down low which is normal and might I say necessary for a truck diesel. As this type of turbo will not increase overall power generation it will not change the life expectancy of your engine.
The intercooler, as Peter pointed out will increase power output just how much more boost you dial up with the waste gate turbo will be the deciding factor for engine life.
The intercooler will extend engine life (provided conservative power generation is maintained) by simply cooling down the hot part of your engine - the valve and piston tops.
The guys who did mine have found a turbo with the correct Perkins manifold. They also asked me what power output I wanted 4cyl 6cyl and V8. I chose 6 cyl so they dialled up 13 psi of boost and adjusted fuel to suit. V8 would be fun but I would put the Perkins intercooled head on first (extra valve springs etc).
Fuel economy is better if I drive the truck at the same speed and acceleration.
However when you can drop down to 4th at 80km/h, pull out and overtake quickly changing up to top and be doing 120km/h+ as you're overtaking, yes more fuel is getting used, but I decide. Low 4x4 speeds ILean still sips fuel just like always.
Please feel free to phone me for more info.
Tim 07 4095 5661
May 31, 2010 at 7:09 PM Flag Quote & Reply

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From Paul Scherek:

Thank you all very much for the comments. I will have a look at Tim's page - sounds good, a "really dramatic and useful change". Thanks Tim for the invitation to phone.
It is encouraging that you have done 140,000 k's with the intercooler, Peter - we all know that your Oka gets serious use, the sort we would all like to do!
David, who is PWR? I will be very interested in your test results. I saw your airbox upgrade - did it make much difference to the air-intake cabin noise?
Cheers all,
Paul
May 31, 2010 at 7:12 PM Flag Quote & Reply

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From David Hallandal:

PWR = Paul Wheel Racing, They do all the radiators for the V8 Super Cars
>> I will be very interested in your test results. I saw your airbox upgrade - did it make much difference to the air-intake cabin noise? <<
No, none; if anything quieter with no drowning noise, but a big difference on the road with driving.
David
May 31, 2010 at 7:14 PM