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New to me donor 6.2L engine


I'm getting there!
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Seguin, TX
so with that said I can safely scout out a 14cm hx35 for when I get to finish up this 6.2 and it will be happier I take it?

I was thinking that the smaller engine have to have the rpms up to get any effect on that turbo.

personally I don't like the rpm to be up above 2500 on the freeway for an extended time. just one reason I still keep it under 65 even now since installing the 3.73 gears. it seems to like 21-2200ish cruising.

what about port matching with the intake, exhaust, and turbo mounting. Ive seen some youtube videos where they grind and smooth out the mount areas to match each others mating surfaces. is there any benefit to this? not actually "porting" the heads but just opening the areas and smoothing them iirc the videos I have seen did them about an inch or so into the ports from both sides.

I'm just gathering ideas and thoughts as I make a "to do list" when I actually start on it. Balancing the assembly is on the list. along with hoping I can convert it to mechanical finding a not to expensive trans controller.

Will L.

Well-Known Member
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Boulder City Nv
You are stepping into chocolate vs vanilla preference here. Opinions are all over the place and I don’t know may that ever did dyno before/after without any other changes to show the difference. Even then doing a different turbo drastically changes how much it helps/hurts in different ranges.

Port matching and light porting doesn’t have much effect at lower rpm for diesels, That part is proven fairly well.

If you watch any of the performance shows for gas or Diesel engines they show where it helps the most is upper rpm and helps top horse power numbers more. The low end torque actually suffers a bit. And by upper, better flow really comes into play at 3500 rpm and up. Many gas engines don’t bother unless they are into 7,000 rpm.

If you are pushing high boost, then it helps more, but flow out of the engine through the turbo is more critical. Keep choked down exhaust or small turbo and it won’t matter what is happening in the engine.

Since we have dry intakes, smooth finish is more popular since we are not pulling fuel out of suspension. But if you run wmi, or propane/nitrous this becomes a negative because you now have a wet intake. Dimpled is proven the best but is insanely expensive.

Having Twisted steel performance do his cnc programed port is best option, trying to copy N8inator builf thread showing port job would be your best diy example.

Unshrouding the valves has far bigger impact, but you drop compression doing it. If running 21 pistons- then it’s a real good idea. You will get the same advantage doing the 1.7 rockers. Do both is obviously best. But this is where a person goes from just t it in to modifying everything to the Nth degree, because next step is roing the larger 6.2 valves.

But if you are running a small turbo like a 14 hx35- it is a lot of effort for low returns. When trying to get better flows- the turbo has the majority of impact. 5% bigger turbo beats 10% better flow every time.