3.8 or 4.1? Opinions wanted.

[skylarkstage1]

3.8 or 4.1

Blackplague, so now that you have our attention, how about going into detail about the early Chevy pistons and 425 nailhead connecting rods.

 

[The Don]

good ish

wow I was always told that you couldn't interchance the chevy parts, was told that they are completely differant. if you could use SBC pistons that would bring the price waaaaayyyy down!
I'm gonna have to keep an eye on this thread and see where this goes

 

[Indy Pacecar]

4.1

I find that I like the4.1 better over all performance is better and I shift the pacecar around the 6200rpm all day long and does just find the motor has been in the car for five years and no problems Thanks! Mike

 

[Adam Connell]

Why not just get a stroker kit for the 3.8??? Do they make a stroker kit for the 4.1 ??

Lol I wouldnt mind a 4.5l V6! It would spool just about any turbo you throw at it ahahaha.

 

[Underboost]

If you want 11's stick with the 3.8 save your money.

 

[forzfed]

I would never throw hypers in any performance motor. Especially boosted. Those things are as brittle as glass. As everyone knows, they're not very forgiving with detonation.

What do think our motors came with? Not all Hypers are made the same. Guys are running 10's on them.

 

[forzfed]

Why not just get a stroker kit for the 3.8??? Do they make a stroker kit for the 4.1 ??

Lol I wouldnt mind a 4.5l V6! It would spool just about any turbo you throw at it ahahaha.

Considering the 3.8 uses the same crank and rods as the 4.1, I would say yes.

 

[yullose]

Use a 4.1 block with the stroker crank and you have around 270 cubes.

Remember that old saying...

"There's no replacement for displacement."

 

[machinegun]

forzfed,

By your statement, yu make it seem that the turbo cars came with hyper pistons. The Buick turbo 3.8 did not come with a hyper piston. It was actually a piston manufacturing prcoess taken from the manufacture of diesel style pistons. I would never use hyper pistons in a forced induction or giggle gas powered vehicle. Most manufacturers wont due to the higher risk of broken pistons due to detonation. I personally would never use a hyper piston in one of these engines. If building a N/A buick motor for a daily driver I might think about it but would probably just find stock turbo pistons or again spend on the forged. Some people have been quite successful using the hypers but I just will not use them for my customers cars. Hope this helps. As for the 3.8, my stocker 119,000 daily driver engin has been 11.56 with no internal mods at all. If I were rebuilding it I would stay stick with the 3.8 that you have. If all is good there then use the known good stuff, save some money and add alchy, and a bigger turbo or some heads and a mild cam or all the above and really have some fun.

 

[Garycar]

My original 3.8 motor ran extremely well for a little motor. It ran 11.17 at 122 mph without any internal mods. TE 34 turbo, weight reduction and many, many runs did the trick. With ported iron heads it ran 10.77 at 125 with no other internal mods. I pulled the motor 3 years ago still in good condition and its sitting on my work bench. In its place I installed a 274 stage 1 with the mods listed in my signature. The big motor makes enormous torque and great for the street. At the track it will run a high 9 second pass with as little as 3-4 #'s boost at the line, 22#'s throughout the run and I drive it to and from the track and everywhere in good weather. The 3.8 would run similar 60' times but needed 15#'s boost at the line. My thought is that the bigger motor might be the way to go. Certainly, there are much faster 3.8's out there than my 274 but I can only comment on my own personal experiences.

 

[Grumpy]

3.8 all the way ..Melissa ran 11.4's @118 for years on a bone stock motor.. did pistons and a girdle with a set of heads .. 10.10 @ 132.66 so far (month ago) . has a little over 8400 miles on it and a LOT of BEATINGs

 

[Garycar]

No one can deny the incredible performance of Melissa's little motor. I'm on her side. If your looking for a T Type with moon roof I know of one in Chelmsford in Canary yellow that's been round the world a few times!

 

[forzfed]

forzfed,

By your statement, yu make it seem that the turbo cars came with hyper pistons. The Buick turbo 3.8 did not come with a hyper piston.

Sorry, I meant they did not come with forged pistons. All I'm saying is you can't group all the hypers together. I'll see what my TRW hyper piston car runs this summer. It is way faster than my old 3.8.

 

[machinegun]

I got you now. I have heard some people running hypers but I am just not in the crowd. So far all I have done are forged. I have had no problems with forgrd over hypers. I have had a hyper break in a blower small block. I just will not take the chance. I would however like to know how you make out though so keep us informed of your progress.

 

[Grumpy]

No one can deny the incredible performance of Melissa's little motor. I'm on her side. If your looking for a T Type with moon roof I know of one in Chelmsford in Canary yellow that's been round the world a few times!

nah I want the "gray" car :biggrin:

 

[ChrisCairns]

Man, this is an old thread.

Years ago people thought the 4.1 was weaker so it wasn't used much. Kinda like the 3.8 would never get into the 9's. Now it's in the 8's. Myths falling rapidly.

I had an old 4.1 sitting around so have decided to use it. I just rec'd all Dan's rotating assembly and am taking it to the machinist tomorrow.

I have hopes of running low 9's with it.

 

[forzfed]

I got you now. I have heard some people running hypers but I am just not in the crowd. So far all I have done are forged. I have had no problems with forgrd over hypers. I have had a hyper break in a blower small block. I just will not take the chance. I would however like to know how you make out though so keep us informed of your progress.

I do agree, that forged are the way to go. But everywhere I looked they were twice the price of the 3.8. So I figured I'd go this route first, then the next time the motor comes apart it'll have JE's, 4340 rods, and crank. Then the motor should be really solid since I already have a RJC girdle.

 

[Indy Pacecar]

Here are the mods on my 4.1 mild cam shaft header and flow master mufflers 600 edelbrock topped off with a old smoky yunic intake (before holly bought them)We are going from a 3.42 to 37.3 this summer. the 30ft times are not what the need to be. The engine has so much low it blows the tires off! Slicks should cure this. And no turbo either! Has forged pistons and a really good crank shaft! We are allready faster than the two speedway We are trying to get in the low to mid 13 sec. Thanks pace car #11

 

[The Don]

270 cid

yullose "Use a 4.1 block with the stroker crank and you have around 270 cubes"

I'd kill to have a 4.5 v6....but now I'm just dreaming huh

 

[yullose]

yullose "Use a 4.1 block with the stroker crank and you have around 270 cubes"

I'd kill to have a 4.5 v6....but now I'm just dreaming huh

The 4.1 block punched out to a 4.0" bore, using the 3.625 stroker crank will give you 273 cubes.

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