19bonestock88’s first generation L61 build thread

[19bonestock88]

Originally Posted by Ecky

How about an oil-water heat exchanger? Many Hondas come with a pancake exchanger that bolts between the oil filter and the block, and takes two coolant lines.

The LSJ had a factory oil cooler but the people who swap the F23 transmission into them have to delete them due to clearance issues with the shift linkage; the oil cooler specific thermostat housing doesn’t play nice. Not sure what it would take to fit one to an L61 or LE5 block and use the F23 transmission

[cRiPpLe_rOoStEr]

Originally Posted by 19bonestock88

I would like to potentially add a limited slip unit even to my F23 to get some traction for the new engine

Even though it's expensive, I'd take a look at those Quaife ATB differentials.

[19bonestock88]

Originally Posted by cRiPpLe_rOoStEr

Even though it's expensive, I'd take a look at those Quaife ATB differentials.

That’s the only one to get for the F23. They do make inserts but they kill the diff bearings

[19bonestock88]

So I wanna visit and discuss the last piece of my puzzle, the engine block. As it is, I have a couple different options to get a fresher block in it.

First major choice, either find a low mileage (under 60K) short block to use. Obviously comes with the peace of mind that if it ran before pulled it’ll be solid and there’s less potential for me to screw it up, with a factory GM block, but with the drawback that not removing the rotating assembly means I can’t improve upon its balance or do major changes to static compression ratio or upgrade the internals, OR I can find a higher mile unit with the intent to tear it apart, save a little up front but spend more later and be confident that everything has been overhauled snd I can precisely balance the pistons and rods, as well as lighten the crankshaft (rebalance for lighter components) or do big increases to compression ratio (they make pistons up to 14.5:1) or engine capacity (de-stroke to 2.0L or bore/stroke to 2.4L

Second choice, and is mainly only available if i choose to open it up, is about engine capacity. I can do a smaller but more rev happy 2.0L and lose some torque or I can switch to a 2.4L block and gain some grunt but lose some rev happiness above 7K

All equal I’m still planning balance delete snd probably a lightened crank pulley/harmonic damper

[Piotrsko]

Old adage: pick a set of needs and go that way and balance that with associated cost and longevity. If the deck stacks towards a revving engine being more efficient, then short stroke is the answer. I have always been an advocate of superlarge bore short strokes. (1906 cc Vw engine) but I had the doors blown off my big bore harley by a long stroke chopper. Not much of a help here, but how long are you thinking of keeping it?

[19bonestock88]

If I can stop what little rust it has I’d like to see another 5-10 years

[Ecky]

Advantages of destroking:
-Longer dwell time - means you need less ignition advance, less negative work done as the piston is rising, higher BSFC
-Better rod:stroke angle, less piston/cylinder wall sideloading, less friction
-Smaller displacement, means lower pumping losses
-Lower rotational inertia

Advantages of stroking (or leaving it the same):
-Greater torque
-Don't need to rev as high to make the same power, and friction goes up exponentially with RPM
-Torque is shifted lower in the RPM band

To my understanding, the biggest reason most highly efficient engines are long stroke, is because you have smaller combustion chamber surface area relative to displacement. Larger bores mean more heat loss. However, your bore is going to be the same regardless. That would only be a factor to consider were you looking at, say, a 2.2L long stroke engine vs a 2.2L large bore engine.

It's also worth noting that your bottom end *might* not be your limiting factor for revving. In the Honda K series, for instance, the ~7100rpm K24's use the same valvetrain as the ~9000rpm K20 type R, just with softer valve springs. The valvetrain is therefore almost never the point of failure - people get stronger wrist pins and lighter weight pistons/rods and rev the K24s to the moon. But, in your case, you might have valvetrain issues if you try to raise your redline at all, or at the very least, the valvetrain will become the point of unreliability.

[cRiPpLe_rOoStEr]

IIRC the 2.0L is often claimed to run smoother than both the 2.2L and 2.4L due to its square bore-to-stroke ratio instead of being undersquare.

[19bonestock88]

The stock valve springs are the limiting factor for revving high, all stock Ecotec valve springs are good to 7200 RPM. They sell stiffer ones but I wanna avoid getting them in an effort to avoid excessive friction. I guess I could do titanium valves and keepers/retainers to save weight and maybe gain some revs on stock springs but that’s awfully spendy for an under 200whp engine

[Ecky]

Originally Posted by 19bonestock88

The stock valve springs are the limiting factor for revving high, all stock Ecotec valve springs are good to 7200 RPM. They sell stiffer ones but I wanna avoid getting them in an effort to avoid excessive friction. I guess I could do titanium valves and keepers/retainers to save weight and maybe gain some revs on stock springs but that’s awfully spendy for an under 200whp engine

Stiffer springs (or cams with very aggressive ramp) cause timing-related failures in K series. General rule there is to stay stock, or you need to seriously improve the tensioner and guides. And then your timing chain life is still reduced. I've seen 500HP NA builds with a K series, but building for NA power ends up being more of a rabbit hole in terms of cost and reliability than forced induction.

EDIT: I've also read of titanium and inconel valves causing rapid wear of valve guides. Definitely read up before choosing any exotic materials, they almost always have some kind of drawback.