4.1 Recipe on gnttype.org performance potential?

[MY3TTYPES]

Does anyone have an idea of how much performance the 4.1 Recipe on gnttype.org could be expected to produce? It sounds straight forward enough, I was what difference the extra cubes would provide. I wouldn't choose to start a project with a 4.1 normally but the car I'm getting (87 GN T-Top) already has this setup. I need to choose a cam and turbo to complete the package and am open to any suggestions or opinions on what parts to consider. The car is intended mostly for daily street type use (but will see the track more and more as is typical), with the occasional education to challengers. Thanks for the help. :biggrin:

 

[MY3TTYPES]

Anyone have ANY input?

 

[BarnesGN]

4.1's are rare on this board, you might want to try www.turbobuicks.com

They have another build "sticky" you might be interested in.

I myself was planning the 4.1 route but I'm having problems finding anyone to build it.

 

[bruce]

Does anyone have an idea of how much performance the 4.1 Recipe on gnttype.org could be expected to produce? It sounds straight forward enough, I was what difference the extra cubes would provide. I wouldn't choose to start a project with a 4.1 normally but the car I'm getting (87 GN T-Top) already has this setup. I need to choose a cam and turbo to complete the package and am open to any suggestions or opinions on what parts to consider. The car is intended mostly for daily street type use (but will see the track more and more as is typical), with the occasional education to challengers. Thanks for the help. :biggrin:

I *had* a 4.1.....
BRC proceeded to hose me on the pistons, but that's another story.

As far as the engine goes, being a 4.1L made it a new animal...
Just any increase in throttle, and the car was just more awake.
With a TA-61, 60 PPH injectors, and just a 206/206 cam it was like a Big Block, boost was effortless, tuning simplier, and yes, it was a great way to introduce the unsuspecting to what a TR is...

A 212'ish cam shouldn't hurt, as the 206 was lawnmower like in mine. A 62 probably wouldn't have hurt either, thou more converter might have been nice, oh, and I was using the stock converter with my 4.1. *Lag*, was an unknown.

Like everything else your results may vary, but that's what's worked for me.

 

[MY3TTYPES]

BarnesGN, Thanks for the input!

Bruce, Good info! I appreciate the cam talk and turbo advice, it helps. I wasn't sure where to begin. What about the #3 cylinder cam problems? Do they apply to the 4.1's also? I was worried about that. Figured a roller would probably solve the problem, but don't know much about them. I know the profile and reaction a motor has is different than with a flat tappet cam. But man are they exPENsive! Any thoughts about that? What other problems might I run into with the 4.1? I do't plan to run it to hard (I never do in the beginning).

Thanks again Gents!

 

[TexasT]

Heres a link to the build

http://www.turbobuicks.com/articles/4point1ForCheap/

I too am working on a 4.1 build.

Good luck with yours.

Rich

 

[8tsixt]

i too am in the process of debating wether to build mine or not. i got a complete 25514291 motor untouched.

 

[CTX-SLPR]

Not following the recipe but I have a 484 4.1 in assembly stage right now. Though I'm a bit more all out with an Eagle crank, billet caps, Diamond custom forged pistons, and Champion CNC Irons. Its also going to be a while till this thing is running due to budget and chassis restrictions. Good to see the 4.1 world expanding... Maybe this will give more incentive to Weber to start stocking 4.1 pistons.

 

[87GNSteve]

The main issue is the block casting number.
http://www.turbobuicks.com/forums/showthread.php?t=45062
This thread as well as the one above has pictures comparing the two.
The 484 block's two center head bolts are close to water holes and have a tendency to crack.
The 291 doesnt have this issue.

 

[TexasT]

Pistons

http://www.bacomatic.org/~dw/bp41/bp41.htm

I found this page interesting on what not to buy.
Also so great pix of assembly.

Rich

 

[Turbo-Archie]

I could read stuf like that all day long..

 

[84TXGN]

I put my 4.1 together a few months ago. I'm a few parts short of a track visit but I'll let yall know as soon as I get back. Mods are in my sig.

 

[BarnesGN]

That article is awesome. Great job Dave!

 

[Jerryl]

I *had* a 4.1.....

Bruce,
Care to explain why you no longer run a 4.1? (Or do you?)

 

[CTX-SLPR]

Bruce,
Care to explain why you no longer run a 4.1? (Or do you?)

It's in the machine shop agian, I think those pistons turned out to be even crappier than the article states. Whatever reason behind being in the shop, thats the reason why its not in the car.

 

[getchasum]

http://www.bacomatic.org/~dw/bp41/bp41.htm

I found this page interesting on what not to buy.
Also so great pix of assembly.

Rich

Interesting.....

Does anyone have more info or links to a diy ceramic thermal barrier system? I've got a spare oven in the basement. :biggrin:

 

[MY3TTYPES]

Great reading! I've never heard of the DIY ceramics either but would also be interested in any links or info.
Does anyone know if the internals of an off center block are the same/interchangable with the on center blocks? I think the heads and intakes are different, but what about the exhausts, valve train/covers and such?

 

[buickguy85]

4.1's

hmmmmmmmmm - now i know what to do with the four 4.1's that i have in storage.

 

[Whitettype86]

That was sweet articale on building a 4.1. I should of done the same thing when I built mine. Its nice to see guys are still interested in building 4.1 still