Thoughts On 4.1 Liter Based Builds?

[Scoobum]

I cracked two separate cylinders and went into the water jackets in a .030 over 109. I'd want as much 'meat' between the cylinder wall and water jacket as possible. I currently run a standard bore 109...for good reason.

Are you telling me that the 3.8L 109 block has thicker cylinder walls than the 4.1L blocks?


Is the 3.8L block more rigid?


What weaknesses does the 4.1L block have?

Call Nick Micale. He's the pro at building 4.1's. He can tell you everything about the 4.1. I'd ask why you want to build a 4.1. I'm assuming you want the extra cubes for a larger turbo/more HP. A stroked 3.8 gives very little in return for the cash you have to throw at it. If all you wanna do is run 10.5 or slower then all you need is a 3.8 with a better crank and two steel mains. Try and get a block as close to standard bore as possible. A 6265 with a race convertor from Dusty would get the job done easily for 10.5's. If you want something slower like mine then the 6262 will get it done easy. If you have your heart set on building a 4.1 then give Nick a call.

[Forzfed]

My 4.1 is bored 0.040 but I do have a girdle.  I'll really put it to the test this summer.

[Cool Guy]

Interesting article on core shift & sonic testing. I read something like that before years ago, but not as informative.

The author mentioned using grout or block filler towards the end of the article. Any benefit in using block filler for the Turbo Buick V6?

Wanting to build a reliable street engine capable of 10's. The Buick Regal is a bit heavy & the displacement is a bit small. Figured increasing the displacement would be beneficial. Plus it looks like building a 4.1 isn't much more expensive than a 3.8. I would like to remove the original engine & moth-ball it.

PS. I've talked with Nick some. It would be nice to deliver my car & write a check, but I can't do that. Will have to build it myself.

[TexasT]

Right there with ya. Pretty much why I picked up the 4.1 about 15 yrs back. I don't think you need the cubes to run in the tens but without em will require more turbo, more boost, and probably more converter to get it moving.


With the advent of decent aluminum heads, this is where I would be looking to make power. TA makes some real nice stuff. And with them being AL you can go that much bigger in compression ratio and be able to make the power there too. Also need the "right" cam profile to get that dynamic cr where it needs to be.

[reality]

Why not just go to a v8 with a turbo?

[Cool Guy]

Why not just go to a v8 with a turbo?

Yeah... But then the car loses its identity. Might as well sell it & buy a plain Jane G-Body to use.


I do have a nice set of aluminum heads.

[Steve Wood]

Why not just go to a v8 with a turbo?

Amen it

Yeah... But then the car loses its identity. Might as well sell it & buy a plain Jane G-Body to use.


I do have a nice set of aluminum heads.

[Forzfed]

Why not just go to a v8 with a turbo?

Blasphemy!!  The first time I took ran the 4.1, I ran it on pump gas.  First run was a 12.3 running big rich and it was all 11's after that.  I had a guy with a Regal V8 come up and was impressed I ran a 12.3 and he was more shocked when I showed him the 11 sec time slips.

[reality]

Methinks you missed the TURBO part tho.

[motorhead]

Why not just go to a v8 with a turbo?

Because who wants to be confused with the likes of me?

[Forzfed]

Methinks you missed the TURBO part tho.

Nope!  There was a twin turbo Camaro that ran at the track with a 630 cu in motor and I still think it was more impressive to see my buddy's Stage II rip off 7.9's with 1 less turbo and with less than 1/2 the cubes.

[Cool Guy]

Anyone have any thoughts on using some block filler?

http://www.hardblok.com

http://www.enginebuildermag.com/2014/07/cracking-block-fillers/

http://www.competitionproducts.com/Rokblock-Professional-Engine-Block-Filler-25-lbs/productinfo/ROK/#.WkxXWBTLQfE

http://garage.grumpysperformance.com/index.php?threads/block-fillers.11033/

[earlbrown]

I wish I would have poured mine (and my 454 boat engine).   Both times I thought about it after final honing.

I've heard you have to do it before due to flex while curing, or some such shit.  Personally I find that hard to believe but I wasn't going to risk a set of new pistons to find out.

Sorta like after ''I heard'' you have to line bore/hone blocks when changing to studs....    According to my bore gauge, that's not based in truth.  Not one bit.

I wouldn't mind reinforcing the cylinders when there's no downside other than a slight weight penalty.  I wasn't going to use that fancy schmancy (read:expensive) stuff though.  I was planning to mix up some sort of plaster 'o Paris with a buttload of brake lathe shavings.

[Cool Guy]

One or more of those links show torque plates in place during the pouring & curing of the block filler. Perform the fill prior to the machining. I suspect that Buick V6 torque plates may not be very common at many machine shops.


Thought I read on one of the product descriptions that the material is not any heavier than the coolant it displaces.


Obviously the block filler should mimic the blocks thermal characteristic s (expansion/contraction) as much as possible.


Anyone know how block fill would affect the cooling of a street driven V6?

[Forzfed]

How fast do you plan on going?  If you're looking for 9's just girdle the motor.  Here is a pic of mine.