Tuskyz28

When you talking 427 i think of a LSX block or LS7 block.
LS7 blocks are known to crack a cylinder wall.
LSX blocks are just to damn heavy and i think all n/a cars perform better with aluminum blocks. Weight on the nose hurts performance. Im now running a LS2 block... before i had a LQ9 block. Never again will i make that mistake of going to a iron block.
I know you can sleeve a aluminum block but you take a chance then. Steve told me that two blocks are never the same in reality after sleeving. One may last 5 months and the next block could last years problem free. I just wouldn't want to risk it. The LS3 block 416ci motors seem to hold up however. I'll take less weight and 11 cubes less anyday of the week.

Ive seen a 416ci car go 9.8s in the quarter at bowling green at the LS fest with a 6 speed on pump gas using factory rocker arms and a hydraulic roller. Car weighed 3450lbs. The suspension was dialied in but not dialed in. Reason i say that the car lifted the front driver wheel pretty high while the passenger side tire stayed low. I was just wondering can anybody top that or beat that....

bortous

I will never use Iron or Cast iron blocks due to the much higher temperatures and big weight penalty.
I will either use an LS9 or Dart Aluminium block when I build another engine one day.
Maybe I might even use an LS7 block if I plan to stay NA. I won't use this block with boost.
I really like the fact that you can make 600rwhp NA with a good LS7 combination.

JakeFusion

iTrader: (7)

Darton sleeved Gen IV blocks are the best option these days... low weight, stronger, and can support 454 with off the shelf parts easily or 468 with more custom stuff.

Dart SHP is a better block for boost and cheaper than the LSX block.

I don't really see the need to run anything else unless it's a JY 5.3L for a turbo build or a 6L JY motor for a nitrous build or something like that.

LS3 is expensive now. LS2 doesn't support enough cubes or bore. LS7 is overpriced for what it is. Getting any of those used helps a lot--but new they are not worth it.

The LS9 is less expensive than the LS3 block now and is better. But I'm not sure I'd pay $2200 for one when the Dart SHP is the same price, has 6-bolt heads, and priority main oiling, and oil squirters too.

I think anytime you can get to 4.100" bore and get to the LS7 architecture, you're going to do better with the motor. Or the aftermarket LS3 stuff--which performs pretty close to the LS7 stuff... But they all need more bore to shine.

As a side note... I've been looking at using a K1 3.900" stroke with the JE Asymmetric pistons. They are very light and allow for some interesting cube combos... 423 with a 4.155" bore or a 429 with a 4.185" bore... the bigger, heavier piston (relative to a 4.03" bore piston) has some of the applied force offset from a slightly smaller stroke.

Tuskyz28

And yes you are correct. The iron blocks does hold heat. My damn floorboard seemed like it was go never cool off. Iron blocks belong in trucks period. Im running the same Heads/cam/intake on the LS2 vs the LQ9 block i had before. The car now feels happier and it transfer the weight better. The nose of my car literally have a stucked up attitude now.

64post

iTrader: (5)

Agree on many points, LS9 is an upgrade over an LS3 block and the price has fallen considerably, maybe it’s going to go obsolete? IDK, just a guess. They have larger 12mm head bolts and steel main caps that are doweled vs. powdered metal that are not. GM claims 900 hp safe too. That Dart block you mention for the same price range is iron and is eliminated from a lot of people’s mind because of it, but ideal for high hp drag race build where the motor can be moved way back.

64post

iTrader: (5)

What? That may be true that the OEM LS3 heads run out of air on a 416, not so with better aftermarket heads. I built a 13:1 416 with AFR heads with 2.17/1.60 valves, LLSR and 105mm Hi Ram to make peak at 7000 + and I have no doubt about it’s ability to do that, NO tow truck 416 motor here, 140 + trap speed, 9.60 or quicker, 625rwhp are my goals. Oh, that’s faster than Hammer’s 10.0 and 139mph with said 670 plus rear wheel BTY.

Darth_V8r

iTrader: (4)

So basically, your AFR heads corrected the very issue that I was pointing out by going with a larger valve? That was a smart move. Did you choose the valve size or was that how they ship from AFR? Also, looks like you made similar decisions I made. Don't worry about torque - build for power and rpm and you'll have torque on a big motor. I aimed for peak HP at 7000 rpm also. sniper though to fit the cowl. And LLSR. I peaked right at 7K, carried to 8K. I'm guessing your cam is mid to high 240's intake?

And I wasn't trying to be that big a jerk about the strokers. I realize in hindsight my post doesn't read entirely what I was thinking. If I could politely rephrase to say the typical stroker builds tend to underwhelm for the reasons I listed? Those builds have kind of soured me on 383's, 408's, 414's etc. mea culpa.

Tuskyz28

I'll take a 416ci over a 388ci anyday of the week . Seem like to me a OEM GM LS3 head would make enough steam to feed a 416 motor. Think about it.... 260cc runners and big *** valves to boot. The main difference i notice is the valve angle is 12 degee (aftermarket) vs 15 degree factory casting LS3 heads. I love them TOW MOTORS.

Darth_V8r

iTrader: (4)

I guess I don't understand the reasoning. I'm going to build a motor smaller than what I want and make less power so that I have options down the road after I blow it up? The whole time I had it, I would wonder what if, and then I'd end up making an excuse to tear it down and build what I wanted in the first place. But that's me. It would drive me nuts. If something happens on mine, I'll resleeve it, but with darton sleeves, or if its cost-similar and saves time, just order a sleeved block from TSP and transfer the internals.

I'm talking LS7 block. I had the same reasoning, NA it's hard to overcome the weight penalty for iron. I know there are some risks with the ls7 block. but I wasn't going to get to 428 (pontiac nostalgia) without it. Car's been running a year now and I don't baby it. I have more faith in a production GM block than a LS7 block with the factory sleeves replaced with fresh factory sleeves

If y'all ever seen a 18-wheeler engine, they are shop-resleevable. There's a tool you use the pull the sleeves out and install new sleeves. No machine work required. Part of the repower kit. New rings, bearings, and sleeves. Kinda cool.

JakeFusion

iTrader: (7)

Darton sleeved... we are talking less than $2500... Still cheaper than an LS7 block, stronger, longer sleeve, and can be taken out to 4.200" if you want, but 4.155 or 4.185 would be fine.

spanks13

iTrader: (5)

Darton sleeved truck blocks will be down at least 20hp against an ls7 block due to a lack of bay to bay breathing. Great cheap option for a low rpm boosted motor or just a high power build that you can turn the ****. Not so great on a high reving NA motor where 20hp can be extremely difficult and expensive to find.

LS7 blocks are gems from the factory for NA builds. If anyone doesn’t want one because they think they’re junk I’ll take them all haha. Someday people are going to want ls7 parts again...I’m almost to the point of buying them for spares for the future.

Tuskyz28

Jake~ you rather have a darton sleeved block vs a LS3/LS9 block?

Lets not forget Darton blocks tend to heat up quicker and run a little warmer vs a GM production block. The darton block also requires Evans Coolant which is higher than the typical antifreeze we get at autozone etc.....

64post

iTrader: (5)

Darth, no offense taken just defending the 416 a bit, and yes I kinda saw what you’re stating about valve size having to do more work to make the same power per c.i. No and yes, 1.60 is the AFR sized valve out of the box and the 2.17 is a size Tony sells for that application, they are the hollow option 94g vs.the 125gm 2.165” that came with the head, they’re 5.200”? long and stainless so they’re apt to be a little heavy. Cam is 251-263 111+4 .700-.680 lift, Steve at Cam motion specced it. Honestly, I think the goals of this motor are realistic, the 4.00” arm might be what makes it go, or it might be what I did wrong, IDK.Going to use a TSI glide with 1.80:1 low, 5800 stall 4:30s 27” Hoosier radial to start off. Let the bench race begin.

Darth_V8r

iTrader: (4)

I think you just summed up LS1Tech...

I think you did it right. I look at bigger motors like this -- the old poncho 428 made 475 lbs of torque almost by accident. Top end (heads, cam, intake) were not really that good, and it still made torque. So I figure that you do not need to build a big cube motor for torque. You need to build for power and uncork it. It'll still make torque. By doing what you did, I think it'll rev great. Sure it might pull the power band down vs a 376 due to the 4" arm, but put that cam and intake on a stock ls3, and you're likely talking 8000 RPM peak power.

I go back and forth on the valves. Lighter is better and more lighter is more betterer. But stronger is more betterer too. I like the titanium valves, but I can see why guys would do stainless. I guess as long as you spring up and give enough pushrod, it's fine, but still seems there would be parasitic losses. Some of the snappiest engines I've felt were LS1's with PSI1511 springs and titanium locks. Over 1-lb out of the valve train vs stock LS1, and very snappy revving motors.

Tuskyz28

Bay to bay breating is worth 20hp ? Thats crazy how a hole in the block can make a difference in power.

rkupon1

iTrader: (3)

^^^doesnt windage from piston squirters on an NA build also hurt it? I for some reason that the squirters were more for big boost build. Correct me if im wrong, just what i thought i read somewhere. By hurt, i mean rob "some" hp.

spanks13

iTrader: (5)

An email from Steve at R.E.D.

“If you are running NA I suggest you start with a new LS2 block. The 5.3 is better for high power or long duration desert racing because the main bearing bulkheads are solidwhich increases the strength. However there is a horsepower penalty at higher revs of approximately 20 horsepower due to reduced bay to bay breathing in the bottom end.”

He said a vacuum pump or dry sump would reduce the penalty but it is still there.

I know TSP cab machine a hole in the block to vent, but still not ideal.

4” stroke cranks add a ton more windage vs a stock stroke crank. I think that contributes a lot to the underwhelming top end performance of most strokers.

Tuskyz28

Thanks for that post. GZ Motorsports makes great vacuum pumps for LS motors. The problem is they are a 1000 dollars starting price and Evans Coolant is about 50 dollars a jug vs antifreeze is under 15 bucks a jug.

Its hidden cost of running a darton block like that Vacuum pump deal you mentioned and the Evans Coolant I mentioned. Im not a fan of hidden costs.

Che70velle

iTrader: (6)

Tusky, you don’t need the Evans stuff for the Darton dry sleeve, which is much more affordable than the MID Darton setup, which does require the Evans stuff. The Darton dry sleeve is excellant for a street build or even a mild race type build.
I had Proline polish my crank when I did my tear down due to rings, and was talking to them about possibly honing/touching my block with a dingleberry setup to remove possible glazing issues (40 miles). Chris told me that if I had the MID Darton setup, he wouldn’t touch it. Said that the setup just doesn’t stay stable enough for his liking.
Hey guys, let’s get back to talking cylinder heads...

Darth_V8r

iTrader: (4)

So can we agree these are the top five concerns when designing and/or purchasing cylinder heads?

1. Intended application
2. Bore and stroke
3. Port velocity
4. Valve job
5. Intake valve size

Note on 2, I did not say displacement. Because if you look at 4.1 stroked 3.9 bore, you have a 392. But you are looking at 220 being about the biggest port you can fit

Now look at a 4.150 bore and 3.622 stroke. Now you can use any head you want and rev to the moon. So it is not displacement so much as the actual bore and stroke. And maybe really only bore...?

CSA likely belongs on the list but not sure if it is top 5. Because it is likely covered by port velocity anyway.