There will never be an absolute formula for an engine.

You can look at things like Ricardo engine simulation to see how complex it can get.

 

You'd go insane deriving it. Here's a simply example....

Your 434 at 4.155 x 4.000 vs a hypothetical 434 at 4.030 bore x 4.250 stroke. Well the formula will put both motors using the exact same flowing heads. But piston speed between the two is not the same, so instantaneous demand at max piston speed is not the same. And additionally, the second engine cannot take advantage of the same size valve as the more normal 434, because of the bore, so this will impact tons of design parameters.

You want more complicated examples, play around with different rod/stroke ratios. Or the same rod/stroke ratio at varying strokes. You'd need a neural net to account for all the variables.

So Like I said, it's a guideline. it gets you close. Then there are guys like Darin, et al, who either through more refined formulas or years of experience that results in a lot of intuitive calculations getting you that last 5-10%

 

A blast from the past.
Check out this 454 Tony did with his LS7 top end:

https://ls1tech.com/forums/dynamomet...s-again-3.html

765hp is quite crazy.
When Brian Tooley did the test back in 2011 on a 454 with his trickflow 245 head and a 251/266 camshaft he got 712hp.
I'm betting Tony's cathedral head is more efficient.

 

That's the LS7 version of that engine.....not the cathedral.

The cathedral made alot closer to 700.

The first time I dyno'ed it it was in the 730's.....hurt it on the dyno (long story).....went back to the same dyno and it made 710.

One of those weird deals that will always keep me up at night.

Fast forward a few years and I freshened the short and installed my new at the time LS7 top end for it after selling the engine with that configuration to a local customer.

With my MMS 265 LS7 heads it made a peak of 767 HP (with one of my ported MSD manifolds as well)

Not an exotic build....just a good combination with solid parts and good airflow. This was only a 251 HR cam....not very large for an engine that size.

It make over 650 ft/lbs also.....it just ran great

Keeping it real with just the facts.....LOL

Anything in the vicinity of an honest 700 with cathedrals and a FAST intake is making big steam.

My ported MSD would have looked good on that engine as I had plenty of torque to give up some in search of a little more power up top but it was years prior the release of that particular intake manifold and the ported FAST was still the only game in town at the time (2012 I believe when the cathedral version was on the dyno)

Catch you guys later

-Tony

 

I just realised it was the LS7 package. Going back from thread to thread confused me a bit.
My bad.
If that engine was running optimally when you tested the cathedrals we probably would have seen 730hp as you did the first time?
765hp is still super impressive for the LS7 especially for such a mild camshaft. Something bigger would have been at close to 800hp.
Mickey's LSX454 with your package is making 700rwhp now so it's probably close to 800hp flywheel.

 

Good to see you posting again Tony. Been a good six months since I seen you on here.

Actually I noticed a couple of names showed up recently. Which is great for the site.

 

It is good.
A lot of the professionals stopped posting on this forum because of all the crap they had to deal with from members thinking they know better.
Plus being doubted and put down.
I found threads from Tony where members were giving him ****. It's not good.

 

I totally agree

 

Which podcast did you listen to about cylinder heads?? Can’t find it and I’d like to listen

 

Go to post 24:

https://ls1tech.com/forums/generatio...g-again-2.html

 

thanks! Glad I can find it on my podcast app

 

Another small update guys.
Stall converter ended up getting readjusted and is going to be a 3500.
I wanted to go lower to around 3k but was advised against it because more than likely we will have surging issues.
3500rpm was the minimum requirement for current setup but it will still drive good.

 

Hey guys I have an update and a question.
First of all pistons are finally ready to be sent out and the parts list is going to be ordered.
The question I have is what to do with my crank and rods.
My current crank and rods are actually K1 technologies and all this time I thought it was callies. My bad.
My builder wants to buy my old crank and rods so if I upgrade to the callies compstar crank and rods it's going to cost me $750 USD including the machine work.
Or I can reuse my old crank and rods and the machine work will only be $230.
What do you guys think?
Go all new or reuse my old ones?
They have only done about 10-15000 miles maybe less.
No racing, just gentle street driving.

 

If you have a chance to get something for your old stuff it's a no brainer to upgrade

 

Is that really an upgrade? I know Compstar is good stuff but I thought K1 was comparable.

 

I like Callies and K1, but I wouldn’t really consider Compstar much of an upgrade over K1. When building my 440, I actually found the K1 rods to provide better clearance than the Compstars. The only advantage I think is that the Compstar rods might be a little stronger, but at the power level it takes to hurt either brand, you should probably be running a more badass rod anyways.

 

More likely to eat a bearing or have a lifter issue before you'd hurt either rod.

 

Well the k1 crank and rods kit is 2k aud
For the Callies crank and rods it's an extra $917 aud.
The price is definitely an upgrade depending on how you look at it. Haha.
Just thought I would ask to see what you guys say.

 

What are the compstar rods rated at for hp rating?
I won't ever be going boost or boost will be very unlikely.
Somewhere in between there.

 

I have ķ1 rods and crank and turn 8000 regularly. Waste money if you eant to