I own a newly rebuilt 408 Stroker race engine I would like to detune to pull my van and trailer. I lack the expertise to know whether I should try to do this. I have been advised to lower the compression around 8.5 with a dished piston and replace the cam to bring the torque in a range from 1000rpm to 2500-3000rpm range. I have all the specs on the engine and van and need some advise.

 

Rather than replacing all of the pistons, just install cylinder head shims to reduce the compression. Much, much, less expensive.

 

Thanks. Good idea, what material are the shims made of?. Any thoughts about using my magnum heads with another cam?

 

Shims can be made of copper or steel. I prefer the steel for street engines because they are more rigid and do not soften or compress as much. Copper shims being softer are more likely to be the cause of a head gasket failure as the shim softens. The copper ones are more for use in racing applications where the engine will get torn down more often.

For the cam, if you're not racing or towing heavy loads then just go back to a stock cam.

 

......

 

Again, thanks for the input. Is this Magnum 5.9 a used or new engine and what is the torque and HP. I have been trying to find the specs on the newer 5.9 magnum engine.

My van (B-300) weighs over 6500 lbs. with the conversion and the trailer weighs about 3000 lbs. I originally bought this engine through Summit Racing and have had it back to Blue Print for the second time under warranty. Summit Racing could care less because the engine is warranted by Blue Print Engines (Marshall Engines, Nebraska). Summit and Blue Print now recognize they should have used better judgement in advising me as they knew of my application. I was ignorant now knowing the torque and HP were not ment for towing between 2000 and 3500 RPM. The engine was dotonated is two cylinders and had a noticable rod knock after 500 miles which finall grew very loud, which was why the engine had to be returned the first time. The engine was set up with Blue Print's specs by a master mechanic. Blue Print has lived-up to their warranty and more but this venture has drained my retirement funds.

I have been advised by an engine builder to use the new rebuilt engine because of the stroke, bore, heads, and to replace the cam and lower the compression. This may be another mistake.

 

Horsepower: 245 hp @4000 rpm
Torque: 330 ft. lbs. (448 N.m) @ 3250 rpm
http://dodgeram.org/tech/gas/specs/5_9v8.htm

Now, as far as using the 5.9L to propel your van and pull that trailer...there is plenty of power to do so. You engine builder is just making excuses for either using inferior parts, or not getting their machining correct.