It looks the end of an era for me and my 350 small block. I've logged over 100 000kms and had two seperate re-ring/re-bearing jobs (one for balancing [trying to chase a vibration] and the other for a wasted flat tappet cam).
It's been a good run with the car doing a best 12.7 @ 105 w/Vortec heads and a XE276HR cam (3700lbs) and a daily driver giving 20mpg+ consistently.
Now the indications are a rod journal is starting to go away.
Time for a fresh engine!
So the question is: 383 or 350?
Criteria so far is:
My block; 2 pc rear main, retro-fit hyd. roller. Bored 030" over.
Assembled with made in USA components. eg. Lunati Sledgehammer crank, Manley I-beam rods, Speed Pro Hypereutectic pistons.
Of course a full short block prep by my engine builder (Beatty & Woods, Mississauga, Onatrio).
Any insights into the advantages/disadvantages of making the move to the 383 from a 350?
I'd carry over the Vortec heads and 276 roller cam keeping an eye on static/dynamic compression ratio. 10:1 SCR at most. Personally, I can see a move to better aluminum heads (and more SCR) and a bigger cam down the road.
The balance of the combo will be as in my signature.
I'd appreciate any comments or insights.

 

Aftermarket 3.75" or 3.875" cranks, and 6" rods are very cheap nowadays.
Advantages are much more bottom end torque and stronger recovery on the shifts. You won't need as much converter or rear gear. You may run quicker by short-shifting, but that depends on a lot of other factors you may also change.

 

[QUOTE=305sbc;4488376]Aftermarket .... are very cheap nowadays.
QUOTE]

I just don't want it to be in quality as well as price.
I'm willing to pay a premium for the best QC in the world and that usually means made in the USA.
To me that's a Lunati Sledgehammer crank. Manley rods. All kind of pricey in comparison.

Quick edit. I see that Eagle, Scat and Lunati are all about the same price for a 4340 forging. Does Lunati use a global supply now to stay competitve? I'm sure Eagle and Scat are offshore however I thought after Holley dumped them, Lunati went back to manufacturing in the US.

 

[QUOTE=305sbc;4488376] ....6" rods.... QUOTE]

Where the stuff is made notwithstanding what's the latest on the 6" rod in a 3.75" stroke format? The last time I saw any tech on it was in reference to the wrist pin being up in the oil ring land. Problems with oil control in a street application kind of made it a compromised setup.

 

Check out Mahle pistons. I don't think the piston pin is in the oil ring for the 6" rod. I'm running a 6.125" rod with a 3.562" crankshaft and the piston pin is not in the oil ring. Also they run the 1.5mm, 1.5mm x 3.0mm ring package. Same as the LS1. Go 383 all the way.

 

In thinking about this months ago I said I'd go 383 for the next build. I have to find a way to make it workable with my current Vortec heads. Keeping the SCR around 10:1 isn't that easy with a 383 and 64cc chambers unless you're using a dished piston or lots of quench, both situations I'd like to avoid.
However the next step from this one will undoubtly be an upgrade to aluminum heads and a bigger cam. I need to have a combo that I can run now (w/Vortecs) and still be a suitable foundation for the next go round.

 

Whya re you opposed to a 12-18cc dish? That's what I would do, and what I plan to do when my 350 ***** the bed.

 

Yeah around 10 to 1 with a 383 will need a 26cc dish I think. Not many pistons like that. I'd stick to a 350-360 incher with a 3.48-3.5 crank. THen again if your spending the premium for that rotating assembly, why not upgrade the heads? 383 will want more head than that. GM makes a 215cc vortec now i believe that would work great, just need to watch your compression. Or go aluminum

 

I've worked it out to a 12cc dish w/ 64cc heads, .026" x 4.10" gasket and pistons .025" below deck. That dish isn't too bad and the gasket and deck height match my current build and there were no problems there. If my block needs decking to square up, I can fatten up the gasket a little.
The upgrade to bigger heads (aluminum for sure) and cam has to wait. I could drop the coin right now for the whole nine yards however I'll practise a little restraint and concentrate on the short block and reuse the existing heads and valve train (which is no slouch).
Still working on the cubic inch. From a price standpoint, it's virtually a dead heat.

 

My understanding is flat tops promote better combustion with greater resistance to detonation. 12cc isn't too bad though.

 

[QUOTE=1989GTATransAm;4488820]Check out Mahle pistons. QUOTE]

That I'll do.

 

you might have better combustion with flat top pistons. but with that many more cubes you will definately make more power and torque. i'd give up a little efficiency for alot more power.

and plus -12cc is not that much of a dish. is this a EFI or carb?

 

I'll probably end up doing just that. Sacrifising some efficiency just to accomodate the longer stroke. If I build the short block correctly, I should be able to get that efficiency back when the time comes for a nice new set of aluminum heads. I would sooner run a thicker head gasket and the resulting larger quench area (while maintaining a piston deck height I can work with later down the road) and then switch to a head gasket that suits the cc of the new heads. I think I have most of the details worked out.
It is a carbed application. The current 670 Street Avenger (which is tuned to the nth degree) will have to give way for something better suited for the increased cubes and ultimately higher revs. (I'm not building a forged bottom end for nothing!)

 

Flat tops are better than the dished IF the dish compromises the quench area, but there are dishes out there that leave the quench intact, and 12cc isn't bad at all.

Maybe I got the wrong impression but I thought you were a drag racer looking to ratchet up to a quicker bracket by upgrading to the 383. If your interest is in just turning higher RPM, then I'd recommend against the longer stroke and bigger cubes.

Personally I like most of the cheaper Chinese made parts. I don't know many people that have problems that actually can be blamed on the quality of the cheaper parts. Most problems are the result of a user or builder error, but if it involves some Chinese part it seems all too easy to just blame that fact first.

Some of the U.S. parts are superior quality with the price to match, and using them is a good plan for an endurance type engine that sees a lot of abuse. Even so, most of cheaper claimer type parts work just fine in the lighter endurance type events like dirt racing. They are more than capable of handling just about any drag racing application unless you're seeing a lot of extremely high RPM, which is rare in drag racing.

As far as the pin in the oil groove, there are support inserts for that, and this configuration doesn't necessarily cause an oiling problem. Again I think this gets blamed when there is actually another cause, like a loose fitting piston or the use of low-tension rings. There are definite advantages to having the pin high in the piston as it makes it more stable, but if you don't like it, the 5.7 rods are also cheap and will work fine.

Of course there are cranks, rods, and pistons that are priced to the moon, and some builders like that. The thing is that the same exact little problems can crop up in an engine and end up damaging parts. It just hurts more with the expensive parts. Personally I think the likelihood of problems depend more on the builder than where the parts came from, but that's just me. It's probably more likely that folks who go very cheap on parts may also spend less on the machining or take more shortcuts during assembly. I'm not recommending substandard parts or anything. I'm just saying that I don't have problems with them.

 

All of the above are excellent points.
Part of my rail against the cheaper import goods is that I make a good chunk of my living in the manufacturing sector. As such it pains me to see these facilities pack it in and head off shore. That being said....
I am a drag racer, however it's just a hobby. It's the prospect of an 11 second time slip with my daily driver that has me on the 383 bandwagon.
As for turning a higher rpm. It's not so much going higher than what I rev now, it's that I want to do it reliably and for sustained intervals. Both the Maxton Mile and open road events like the Silver State Challenge that are on my agenda. I can't (won't) run those events with a cast crank and stock rods. Hence the forged short block.
The pin in the oil ring land still presents a compromise to me. I've been in situations (like being stuck in traffic or even pulling a trailer cross country [ yes I drove 2500 miles pulling a u-haul with my IROC!]) that raise concerns over oil control. The 5.7 rods (as you mention) may be the way to go.
I will say I appreciate the input to this point. I'm still shopping and researching. Here's a link to a shortblock I came across. Pretty stout piece from what I can tell. The forged pistons (as opposed to hypereutectics) might be overkill and present some drivability issues as a grocery getter however the price for what you get is pretty good. I'd have a hard time hand picking components, having the block machined, internal balancing and assembly for the price of this short block.
Just one example so far.
http://www.summitracing.com/parts/HRS-SBTP383F/

 

I for one can totally respect buying american made on principal.

I'd rather push a GM than drive an import!

 

The only unfortunate thing is that there's little we can do to stem the tide.
We're told to think globally not locally and that's a drag.

 

[quote=Grumbles;4489823]I for one can totally respect buying american made on principal.

I'd rather push a GM than drive an import![/quote

I hear you on that one. haha.

 

Skinnyz, The 383 will be great for you tow vehicle

I also am not happy about the U.S. companies having to close and lose business to overseas, but that's the way of free trade & enterprise. I'm not angry at China for making and selling products to us, nor am I mad at Americans for saving money by buying the cheap Chinese stuff.
I think the problem is politics rather than the free trade. I'm angry that our government regulates and stifles business to the point where we simply can't compete anymore. The only incentives we're given are ones to become simple consumers instead of producers. As a consumer I'm naturally going to spend the least amount to do the job to my satisfaction. I wish I could change it. I'd love to have ALL U.S. made engine parts and tools. I just wouldn't have half the stuff I have if that were the case.

This is a little off-topic though.
I think forged pistons have more problems with oil control due to the loose fit. They only truly expand out to proper fit after you have been at WOT for a few seconds and the piston reaches a new temp equilibrium. Even then they are originally sized for the size they take after being at high RPM for a while. There are some with lower expansion rates, like perhaps the Mahles, but they are very expensive. I haven't tried that many types of pistons myself and only have experience with Speed-Pro/TRW, JE/SRP, and KB - expansion rates being in that order. If you don't use a power adder the cheaper KB claimer series works great. I deburr and polish the tops and run them pretty tight. I run them pretty tight, but I also make sure the cooling system is very healthy. I know that towing will build up heat in the metal and oil, but I really don't know what it does to the piston temp. It may not be that big of a jump. I know a 383 won't be quite so loaded when towing a small load. A timing retard chip like an MSD might work well for towing.

 

They make two different alloys of forged piston, 2618 and 4032.
2618 usually is used in boosted/nitrous applications since its a stressful environment. Its more forgiving in stressful situations. 4032 are harder and wear better, and can be run in a tighter clearanced bore. Usually good for n/a builds since the piston is not under as much stress.

Either one is fine for your build, just use good rings and good round bore and it should not consume oil.

 

Kind of funny actually. My towing anecdote was just to highlight the kind of abuse I put an engine through.
More to the point what I need from an engine is one that I can start on a cold Canadian morning and go and get coffee. Or take a 3 hour sprint down the highway and go drag racing for the day. I have plans to drive out west again this year as well. (NO TRAILER TOWING!) So you see how versatile my engines need to be.
Except for the cast crank and ARP bolted stock rods, I was quite happy with my 350 in that it did all of the above. Deadly reliable and good gas mileage to boot.
To reinterate and go over what's been discussed: I like the notion of a 6 inch rod however as has been pointed out, there may be oil control issues when used in my application. It was also said that there's not much to choose between a 6" vs a 5.7" rod in terms of performance. I can see how if I were too build a drag racing only engine you would want to leave nothing on the table. This isn't the case this time around.
As far as forged pistons go, I wasn't aware of the various types. Traditionally, forgings aren't that suited to what I wish to do however that info may be dated. I'll investigate further to see what the latest scoop is. I was very happy with the coated Speed Pro hypereutectics I've been running. I had a close look at them during a couple of quick rebuilds and they were none the worse for wear.
It's still a toss up between getting my own components and machining my old block or buying an already assembled shortblock from Howards or Dart (can you say 400cid?).
Thanks for all the input people.
Anything more?
It'll still be Vortec headed w/ a XR276HR cam regardless what I decide (at least for the time being).