300WHP Supernatural 3.XX Coming Soon! (Page 1/54)
La fiera JAN 01, 09:47 PM

Started working on my next short block and my goal is 300WHP with Cast Iron heads, off the shelf parts, no custom pistons or rods, no boost, no juice and using an unconventional approach. Will I be able to make it? We will see!
I can hear some of you already, same people that said 250WHP was not possible out of a 3.4 Iron head engine.
It's pretty disappointing when someone goes through the trouble of a V8 swap with a bigger mass to haul around and heavier and here I am with a stock 60* V6 design almost matching V8 power in a different way.

I sincerely respect everyone's choice of engine swap so I expect you to respect mine.

Let the hating begin!!
da.slyboy JAN 01, 11:12 PM
I just want to see if you sell your current 250hp v6 when this new project is complete😜😎
FieroWannaBe JAN 02, 10:47 AM
I am curious, do you plan to do this with an off the shelf cam grind?
I just don't know of any that are aggressive enough, 300WHP is not an impossible goal, but I believe it will take a solid roller cam and lots of RPM to get there, maybe even Falconer heads. This is like asking a 350 to make 500WHP through a non-vortec SBC head, It may have been done before, But i have never heard of it being done with factory heads.

Good Luck.

I recently built a 3.4 DOHC motor, my cams spec at 286 degrees duration seat to seat (236 at .050), This is a hydraulic direct bucket cam. I don't anticipate getting much over 275 hp at the crank. The intake is a short runner, with a massive plenum, and a 3" Throttle.
La fiera JAN 02, 12:16 PM

quote
Originally posted by da.slyboy:

I just want to see if you sell your current 250hp v6 when this new project is complete😜😎



I can build you one to suit your needs.

Blacktree JAN 02, 01:24 PM
I'm interested in seeing what the "unconventional approach" is going to be.

Are you still keeping it naturally aspirated?
Spadesluck JAN 02, 01:46 PM
Very cool. What kind of power band would you be looking at? The only argument that can be made is the V8 powerband would be more ideal. Not to take away from you accomplishments by any means though, keep on keeping on. There will always be haters.
Patrick JAN 02, 03:41 PM

quote
Originally posted by Blacktree:

Are you still keeping it naturally aspirated?



That's what the man says!


quote
Originally posted by La fiera:

no boost...


Easy8 JAN 02, 08:55 PM

quote
Originally posted by La fiera:


I can hear some of you already, same people that said 250WHP was not possible out of a 3.4 Iron head engine.
It's pretty disappointing when someone goes through the trouble of a V8 swap with a bigger mass to haul around and heavier and here I am with a stock 60* V6 design almost matching V8 power in a different way.

I sincerely respect everyone's choice of engine swap so I expect you to respect mine.

Let the hating begin!!



Not hating here, however humor me and allow me to make a point or two. I will say your work on the 250 hp set was impressive and hats off to you. I am sure this one will be just as good.

First point, yes you make V-8 power in a different way. Trouble is you had to do a whole bunch of work to make that power. Your last build was pushing the limits and this one will be as well. Yes I think you can do it, but you can drop a V-8 in the car pretty much stock and make 250 hp with ease. No extra work needed. The V-8 has tons of HP to be found with simple bolt on parts, they can be taken way over 400 hp pretty easy.
Now for a second point, you will say they are heavier. Yes they are. From a quick google search I get the LT1 at 550, the LS1 at 500 and the 3.8 at 450. (estimated due to differences in bolted on parts) I would argue that the V-8s ability to make more power easier is worth less than 200 lbs of extra weight.

All that being said, I will be watching to see if you can do it, as I love when people prove the crowds wrong.


Edited because you should always read it before you post it so the words are not out of order.

[This message has been edited by Easy8 (edited 01-02-2018).]

Will JAN 03, 12:35 PM
Lol... good luck!
Especially with a light weight clutch, driveline loss won't be a huge factor, but you'll still need 320-330 HP at the crank to hit 300 at the wheels.

Basically, you're going to need three things to hit that number:
-Outstanding port work. The "port" being the entire intake flow tract from the plenum to the valve... the engine doesn't care whether that's in the cylinder head or the manifold
-Solid roller cam. Yeah yeah yeah, people like flat tappet cams for inexplicable reasons. Rollers are just better. Period.
-High compression. 10:1 is not high compression.

With those big three in line and other details dealt with appropriately for the build, you'll hit the number. That's pretty much the max that iron heads are capable of, though.

Getting power out of an engine with mediocre head flow has always required getting everything other aspect of the build on point. If you're using shelf GM pistons, that's going to be difficult, as GM never built pistons to run high compression with iron heads. The iron head pistons will run 12:1 or thereabouts with the smaller chambered aluminum heads. I guess there could be an application with adaptable pistons, but then you're likely not to have the right wrist pin size, so then you have to bush the rods... etc.

In my experience, buying what the build needs is a better value than trying to adapt something that's close.

If you haven't been using gapless top rings... you should be.
lou_dias JAN 03, 02:36 PM
shaving 3.6 DOHC pistons flat combined with longer rods will give you 3.5L and higher compression... using the Gen2/3 1.76" valve will also boost compression...
GM rods are off the shelf at least up to 6"...

Go La Fiera! Go!