Injector Limit for Cast Oval Bowl Pistons???

[Bdsankey]

@Bdsankey I've have shit luck with OEM GM black head bolts, I've lifted everything set ive had with a tow tune, the silvers head bolts have held..as long as I install them right .
Current truck hasn't ran long enough to lift them yet🫣

Naturally the OP is well passed OEM head bolt capacity for goals

In my opinion OEM head bolts are not the weak link in a stock engine, the rods typically are. I've seen tuning issues (timing) causing massive cylinder pressure spikes which doesn't help anything. I've personally made north of 800whp on them.

As for the fastener the OP is looking at, I really hope nobody builds an engine these days with aftermarket hard parts and uses OEM style TTY head bolts. Most go with the lower grade ARP as there is a major cost increase going from ARP 2000 vs 625. The 625s are a pricey unit but worth the money. At his 850whp goal, I personally think his crank selection is unnecessary as a Callies Compstar is proven to WELL beyond his goals but a billet crank ($5k vs $1.7k) won't hurt the engine's lifespan.

 

[Fingers]

The ovals have proven themselves. There have been three types of "failures" and only 4 sets involved in total that I am aware of.

Bret managed to crack the piston at the top of the wrist pin bore. Not a true failure, since no parts were lost. But the cracks were there. Didn't discover the cracks until he moved on to a totally different setup.

Two customers had skirts break. Same production batch. This seemed to be a mfg flaw with the bonding of the metal insert to the skirt. In both cases, the customer was running too big a PTW clearance. It should only be 0.0015'-0.002" for casts on a fresh build. New castings don't have the inserts any more.

Last was a hole into the oil gallery at the deepest part of the bowl. The autopsy reviled that the gallery was cast higher than normal. (casting shift)

I recommend the Dynomite Diesel oval pattern injectors. I'm very happy with mine as are others.

The latest casting blanks are much lighter than the past. The dies have been updated recently as well as the design and there are no metal inserts in the pistons other than the upper ring land.

The weak point with the cast pistons is they don't like water/meth and or Nx. Eats up the top. If you think you might go this route, go with the gold coat I offer.

As far as the OP's question about injectors; Go as big as you want. You will have other issues before the pistons give out.

 

[Dozerboy]

Fingers pistons have gone into the 2k range with no issue iirc.

100% overs on a single 64 is a good route. Leaves room to grow for compounds. Tbh, a 1500uS tune on a single 64 and 100% overs will be smokey. Add a compound and its going to make another 100hp on the same tune just from cleaning up the smoke

That's exactly where my tune/truck is right now and it just hazes after limiting the fuel down low. I run a 12mm stroker.

Truck feels lazy to me when it's tuned to run "cleaner". I think a lot that is the converter that's just to tight, but my transbuilder says it's the turbo...

 

[Bdsankey]

I recommend the Dynomite Diesel oval pattern injectors. I'm very happy with mine as are others.

I have been incredibly happy with the DDP oval pattern stuff. It's been a welcomed change to make the "be all end all" street/strip/weekend warrior combo!