V6Discussion and questions about the base carbureted or MPFI V6's and the rare SFI Turbo V6.
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I'm looking for rebuild kits for either a 350 or 383, and I'm wondering if anyone can tell me the advantages/disadvantages of cast pistons vs. forged pistons. Also, Domed pistons vs. flat top pistons.
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See pics @ Billy's Firebird
92 Bird 3.1L Auto
Best $750 I ever spent....
DRIVE IT LIKE YOU STOLE IT!
Kills:
93 Mustang LX (Before Mods)
98 or 99 Dodge Stratus (tough one, edged out at 40)
92 Camaro RS 305 TPI
97+ Honda somethin or another...modded....kept at my door the entire way
Close Calls
94 Grand Am 3.1 V6
92 Cavalier 3.1 V6
01 Porsche 911 Turbo (Had em till first gear)
Mods-Jet Stage 2 Performance Chip, Accel Cap/Rotor, Accel 8.8 MM Wires, Accell Coil, AC Delco Rapidfire Plugs, Dynomax Catback, K&N
AIM name OVRCLCK350
cast are cheap. but pretty weak. get the job done for a stock motor. hyperutechtic are i bit more expensive. can handel mild shot of nitros, aboot 100hp. they run a tighter wall to piston clearance. they are more brital that cast. good for a 400 hp motor. forged maga expensive, very strong, can take large amount of nitros with out burnig a hole in you pistons like cast and hyper.
flat top vs. dome
aside from the obvious of afecting your comp ration the dome afects flame travel. people say you will lose some power but im sure the diff would be neglagable. hope this answers your question
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when the green flag drops the bull$hit stops
Curent: 350,performer RPM intake ,650dp, 700r4, headers, 3inch exhast
Spring 01: 406, Comp 282 solid cam, 2400 stall converter, every thing else the same.
Actually, the "hot setup" now seems to be small combustion chamber with dished pistons. This is how they are able to achieve much higher compressions with the lower grade of fuel today. Also, produces less emissions.
Forget "pop up" pistons. Those belong with the dinosaurs. We've advanced much further in the last 50 years. Pop-ups where necessary when the heads had much larger combustion chambers. Small combustion chambers are less prone to detonation and promote more "swirl and tumble" for a better mixture. That is why Nascar now run really small combustion chambers in the high 30 to low 40 cc range.
I dunno; it seems that cast pistons can handle a nitrous shot every now and then. As long as the fuel pressure's high enough, and the nitrous shot isn't too heavy, the cast pistons should be fine.
That's why I'm going with cast when I rebuild a 2.8. I don't see the point of spending an extra $300 for forged pistons on a V6 - for a V8, definately, but not for my 2.8.
I seem to remember some people (Vader being one of them, I think) disliking the Hyperuetic (sp) pistons for some reason... if you searched the tech board for "Hyper piston" maybe you could dig up more on it.
IF you are rebuilding your V-6 engine, go with cast. (from $100 - $390)
IF you are setting to try to destroy your V-6, inform the machinist of that decision, he will suggest piston material.
For a V-8, it really depends upon your budget.
For a 350, go with forged, extra cost is nothing. ($400 forged/$300 Hyper pistons)
For a 383, now you are talking serious money.
$410 Hyper pistons $650 w/crank
But find a very fair price for all these items at Northern Auto Parts Wholesale
800-831-0884
You will be pleased with this option. They only sell TRW stuff.
Don't forget to add machining cost for your project!
These costs are only for the bottom end block & gaskets, not parts for the heads.
Build a 350, you'll do fine.
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Chat Soon,
KED85
Karl
1985 Firebird 2.8 to 3.4 swap project for Smog Happy LA, CA
I'm building up a 350 or 383 and using the TPI from an 87 305 Formula. I'm looking at the rebuild kits from www.speedomotive.com so that's why I'm debating cast vs. forged.
Ovrclck, What you need to do is decide how you are going to use the engine. Is it going to be a 450 hp monster? With NOS? 13.5:1 compression? If not you don't need forged pistons. I've got 10:1 CR cast pistons in my 500 and haven't had a problem. I most likely won't either. I don't use nitrous in that engine, I don't abuse the engine by trying to pull 10,000 lbs down the road a 90 mph uphill, although I think that engine will do it! I do have forged 10.3's in my 402. I have plans to add NOS in the future and I don't like to use cast with the cylinder pressure that NOS causes. Your asking for a broken piston there.
If all your going to do is put together a nice streetable engine 10:1 or so with maybe small quantity of NOS 75 hp or less you'll be fine with cast. If your going wild and trying to push the limits of what pump gas can do, you need forged.
Forged pistons do have some other advantages though. They expand less so you do get better clearances. They add to the "G" factor, as in "Gee, I bet thats fast", and if you decide to go with forged you won't have to carry around the weight of that $100 bill.
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Remember, Behind every successful man is a suprised mother-in-law.
-Gallager Qsac
<font face="Verdana, Arial" size="2">Originally posted by TomP: I dunno; it seems that cast pistons can handle a nitrous shot every now and then. As long as the fuel pressure's high enough, and the nitrous shot isn't too heavy, the cast pistons should be fine.
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BTW Tom, Cast pistons can handle it, how many guys on the power adder board are running stock shortblocks and NOS? When was the last time the factory put out a plain jane 305, 350 or V-6 forged pistons? It's like you said though, you can't put a 300 hp shot to the thing unless you want the engine to fit in a 5 gallon bucket
For what it's worth.
Goodwrench sells a wonderful option a built 350 for about $1200 at any dealership.
Part number 12355345.
It's done.
Complete
Drop in your engine bay and drive away.
No parts or machinist costs.
Just sell you old engine to someone to make back any costs you incur.
Or the complete legal 350 dual cat convertor exhaust package one for about $4500 or so.
That's part number 10185077
Plan your options, you'll win in the end!
That's why I did my 3.4 swap.
I won.
The swap cost me less than any other option. And it wil pass CA emissions. I am checking tomorrow for my test in July.
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Chat Soon,
KED85
Karl
1985 Firebird 2.8 to 3.4 swap project for Smog Happy LA, CA
<font face="Verdana, Arial" size="2">Originally posted by Ovrclck350: I'm planning on about a base of at least 300HP w/ a 100HP shot of NOS later on....if I go w/ the 350. If I decide 383, i won't go nitrous at all.</font>
Myself, in that situation, I'd go with forged for the 350 and cast will do for the 383. If all you plan on getting out of a 383 is 300 hp you'll have no problems.
The Goodwrench 350 is a "factory claimed" 300 HP. But the old way, 4 bbl carb.
The street legal 350 swap package is also in the same neighborhood. Also 4bbl, but "electric one" works off a ECM & distributor signal.
Street legal 350 requires electric in tank fuel pump.
No requirement for the Goodwrench 350.
That Goodwrench is a great option. This is the engine the magazines have been writing about.
Swap out cam, swap heads to the Vortec Truck heads, add headers, close to 400 HP for a budget price! And a new engine, too!
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Chat Soon,
KED85
Karl
1985 Firebird 2.8 to 3.4 swap project for Smog Happy LA, CA
Why not just go with the new HT 383 from Goodwrench. Though it is designed as a truck motor it has a TOUGH bottom end (4 bolt mains and forged crank and rods). Basically it has the same bottome end as the Fastburn 375 HP if I recall correctly. It has the best there is.
NOW that motor, swap the cam (possibly the heads if you want even more HP) and you'll have a real screamer. Why build a 383 when you can buy one with a warranty? Imagine that combo with the LT4 Hot Cam and the Fastburn heads. With the 350 it made 430 HP (aka ZZ430). I suspect that puppy will make close to 475 HP. (Crank HP of course, probably high 300s RWHP).
Want to look at different heads and combo? More HP yet.
Well, I have lots of stuff laying around that I can take from, and I'm really wanting to be able to say "I built it" Plus, I'm watching my money. The project won't be done until late summer probably. I have a donor 305TPI Formula, so i'm wanting to keep TPI.
