IHADAV8.com - Turbo Buick Tech, and Nonsense
Tech Area => General Buick Tech => Topic started by: Cool Guy on December 29 2017, 10:58:47 PM
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How well does the 4.1 liter Block perform / hold-up as compared to the 3.8L 109 Block?
Is there a date range or model of the 4.1 that is more desirable than others?
Will the 4.1 oil pan fit the Regal?
I understand the 4.1 Block will require machining for a turbo oil return port. What other modifications are needed?
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How well they hold up depends on the loose nut behind the steering wheel.
The oil pan's aren't the same. The 4.1 is an early block so it's a 14 bolt block.
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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.
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If I was gonna build a 4.1, I'd be calling Nick Micale.
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The "291" casting is regarded as the one to seek though I have seen where people have used a "484" casting also.
Drilling and threading a block isn't that big of a deal. Or you could rig it up where it dumps back into the oil pan if that would seem easier with a welded on nipple or something.
Chamfering the head bolt holes seems to be a way to keep the deck from cracking. Over on the TBS.com there was a sticky of how one person did his. ill look for a link.
Found link
http://www.turbobuicks.com/articles/4point1ForCheap/ (http://www.turbobuicks.com/articles/4point1ForCheap/)
Some other links for those looking for something to read
http://www.turbobuicks.com/forums/showthread.php?t=28069 (http://www.turbobuicks.com/forums/showthread.php?t=28069)
Not sure if you will see it or how Photobucket goofed up the pix but here goes.
(https://s25.postimg.org/yvena2jpr/C_Data_Users_Def_Apps_App_Data_INTERNETEXPLORER_Temp_Saved_Images.jpg)
Maybe you can see the casting number ending in 291 toward the top of the pic about a third of the way from the right.
I've been planning a 4.1 build for well over a decade. Pistons have been my hurdle, or more correctly the cost of nice forged pistons. And with the advent of good forged Chinese cranks I think that is the way to go. My theory is that the flex of the stock crank has torn up more stuff just behind detonation at the top of the I tore it up list. And a forged crank minimizes the flex so it cam stay together and not bust out the webs in the block.
I want to go to a 4" bore as the sbc offers pistons and rings in that size. And with the advent of "less expensive" forged pistons available in what ever compression height you want it is easy to get where you want with a zero deck to help with the detonation. And a set of aluminum heads a 9:1 compression ratio becomes real streetable or at least I'm going to find out.
Good ness this escalated quickly. Sorry it turned into a novel. I have big dreams.
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Pistons have been my hurdle, or more correctly the cost of nice forged pistons.
I want to go to a 4" bore as the sbc offers pistons and rings in that size. And with the advent of "less expensive" forged pistons available in what ever compression height you want it is easy to get where you want with a zero deck to help with the detonation.
It's be nice if 4032 forgings would quit going up in price. They're almost as expensive as 2618's now. I still like the 4032's better for street builds.
There's no reason to go straight to 4" if you don't have to. Even though that's 'only' .035" over. The block will dictate how far over it takes to come clean, no reason to go screaming past that if you don't have to. My first block wouldn't come clean at .060". I wish I still had it, I would have sleeved all 6 holes and build a backup.
Keep in mind those pistons don't use the thick factory style rings, so ring availability is different animal since mine can go either 1.5mm or 1/16" (or 1.2mm, or whatever...).
This link shows my 4.1 build (with the crappy FMO pistons that caused me so much grief and the reasons for designing my slugs). http://www.turbobuicks.com/forums/buick-v6-turbo-tech/88129-day-life-earl.html (http://www.turbobuicks.com/forums/buick-v6-turbo-tech/88129-day-life-earl.html)
Notice it looks just like any 'normal' 3.8 build with only a couple exceptions. Granted I ran my drain to the pan and I lowered my rocker shafts but everything else was the same as a 3.8.
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Thanks for the info. I've seen the "4.1 For Cheap" write up before. It's a bit dated & I was wondering if there is newer info available.
Knew about the Oil Pan bolt pattern difference. Does the original 4.1 Pan have the same shape as the 3.8?
Is the "291" casting found in any certain year, make & model?
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It's dated because Make had to settle for the crappy FMO hypers at the time. When I built my 4.1 I cracked 2 and 4 in less than one second when it was new. I though I blew a gasket between the two cylinders. After shotgunning a new $100 Cometic in there and still had 40PSI, I tore it down to the bare block. Got another set of hypers and broke another one in less than a month....
Needless to say I have forged slugs now and they can take a freakin beating.
Basically the same shape on the oil pan. The 20 bolt pan is pointed on the front and as three 1/4 holes in the shape of a triangle at the timing cover area. The 14 is blunt and has two 3/8 holes for that job. The 109 blocks are based on the earlier 14 bolt blocks so the architecture is pretty much the same. They just changed the timing cover for some reason and added more threaded holes in the pan rail. If you REALLY wanted to redrill a 20 bolt pan and make it fit, I guess that's possible. I would definatly use The Right Stuff and no gasket (and still might get oil weeping).
If you look at the link I posted you can see my 14 bolt pan that I added a turbo drain and a baffle I made from a Sony VCR cover using my GN pan as a pattern.
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I'm only able to view page #1. Won't show the pages after that.
How about fitting the 3.6+" forged stroker cranks into the 4.1 block?
What length rod is available that won't push the piston pin into the lower ring land?
Is a reduced base circle camshaft required to clear the connecting rods?
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I don't think there is a such thing as a reduced base circle cam for out engines. Cam to rod clearance can't be a 'published distance' per se. It depends on the exact shape of the exact rods in the engine. The only way to know is to mock it up, measure, and grind if need be.
On the shortest CH you can achieve that's kind of a trick question. First you have to know the EXACT numbers as far as deck height, head CCs, etc so you know what you want... The other factors are the ring pack. Thinner rings leave more room for a pin.
The way I start is take the deck height, and start with .040" off the had. That math will show a starting point for CH and static compression ratio. Then adjust from there if needed.
Also, there's once get out of jail free cards that is a oil ring support rail. Obviously the pin can't get into the top rings, but it can encroach into the oil rings space if needed.
That being said, I made a set of slugs a couple months ago for a 4.1 stage stroker with a 6.500" rod. I don't remember the exact compression height but it was short as hell.
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How about the imported forged stroker cranks?
Which make & model has the best quality steel & tolerances?
I think I would prefer to convert to internal balance, so would require a suitable flex plate & damper also?
I've been reading up on connecting rods & stroker clearance issues. Sounds like Molnar has a rod that provides more clearance than others. What happens when a longer than OEM stock rod is used?
All advice is appreciated. Thanks.
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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?
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the 4.1L is a Siamese cylinder arrangement like the sbc 400. This puts the cylinders quite close together and there aren't any cooling passages between the cylinders. The cylinder wall thickness would depend on core shift in the casting I would think. But finding a "thick" one out of the small numbers available would equate to a "needle in a haystack" if you ask me.
If you are that worried about it TA performance sells a right nice after market block.
http://www.taperformance.com/proddetail.asp?prod=TA_V3800 (http://www.taperformance.com/proddetail.asp?prod=TA_V3800)
Wouldn't really fit the budget theme though.
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TA Performance has some nice stuff. Out of my price range though.
Familiar with the SBC 400 core shift.
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For those who want a little core shift info.
http://www.v8buick.com/index.php?threads/understanding-core-shift-in-the-455-block-why-sonic-checking-is-so-important.171953/ (http://www.v8buick.com/index.php?threads/understanding-core-shift-in-the-455-block-why-sonic-checking-is-so-important.171953/)
Applies to all cast engines. And gives some info on how to tell the thickness and such.
I would think if you do a little sonic testing to the cyl walls and they are pretty equal you will be alright for a street engine. If you are thinking 35psi and some alky/race gas, this might not be the best way to go about it.
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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.
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My 4.1 is bored 0.040 but I do have a girdle. I'll really put it to the test this summer.
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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.
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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.
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Why not just go to a v8 with a turbo?
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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.
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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.
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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.
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Methinks you missed the TURBO part tho.
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Why not just go to a v8 with a turbo?
Because who wants to be confused with the likes of me?
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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.
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Anyone have any thoughts on using some block filler?
http://www.hardblok.com (http://www.hardblok.com)
http://www.enginebuildermag.com/2014/07/cracking-block-fillers/ (http://www.enginebuildermag.com/2014/07/cracking-block-fillers/)
http://www.competitionproducts.com/Rokblock-Professional-Engine-Block-Filler-25-lbs/productinfo/ROK/#.WkxXWBTLQfE (http://www.competitionproducts.com/Rokblock-Professional-Engine-Block-Filler-25-lbs/productinfo/ROK/#.WkxXWBTLQfE)
http://garage.grumpysperformance.com/index.php?threads/block-fillers.11033/ (http://garage.grumpysperformance.com/index.php?threads/block-fillers.11033/)
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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.
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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?
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How fast do you plan on going? If you're looking for 9's just girdle the motor. Here is a pic of mine.
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I went ahead and bought a torque plate. Just bolt the heads on if you don't have one. That is what you do with the one torque plate, bolt a head on the other side. Also torque the mains on there. I think on a street car I would do a half fill up to the freeze plug holes in the side so there is some cooling going on in the block.
Another thing I Saw recently on a different brand was a pretty thick "strap" that was bolted on top of the stock looking main instead of a full on girdle. I thought I might look into doing something like that with a forged chinesium crank. I don't know how much clearance there is in the pan but if a girdle fits I don't see why these wouldn't if you made them thin enough. I guess with the forged crank and the replacement middle main caps it would be plenty for a street car.
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I'd like to avoid using a girdle. Looks like it would add more complexity & costs than I really need.
I have seen a picture of an engine that had the mains strapped together before, but no information on the straps. Seems simple enough. Would require a certain type of material, perfectly flat surfaces & longer studs I suspect. Don't know what the best material would be. Aircraft grade aluminum? Steel?
What are the typical weaknesses or failures on the turbo Buick V6?
How much MAP is typical? 24-30 psi?
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What are the typical weaknesses or failures on the turbo Buick V6?
The owner.
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What are the typical weaknesses or failures on the turbo Buick V6?
The owner.
He knows what he speaks!
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Let's remove operator error from the equation for now.
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In that case, there are no weaknesses.
Still need to replace the timing chain, valve springs, and vacuum hoses though. :D
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I went north of 30psi accidentally on my 4.1 when a vac hose went. Surprisingly it held up well. I did tweek the headgasket but it still held up and I did another 7 1/4 mile passes. My major problem was the billet cam wearing into the front of the block and the crap taking out my thrust bearing.
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Bison has shoved several minutes of 9 second power through the stock short block in his blue car. I run 7 flat all day long in my own car with the stock short block. Durability depends on ones tuning ability.
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Bison has shoved several minutes of 9 second power through the stock short block in his blue car. I run 7 flat all day long in my own car with the stock short block. Durability depends on ones tuning ability.
How many miles are on these engines?
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By this time.. Somewhere between 150,000 and 200,000+
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Mine just turned 136K.
Third owner, adult owned, mostly original. I've improved fuel supply (Hot-wire/Walbro 255/Adj.FPR), cooling, braking & other supporting systems. Engine internals untouched. Trans is original with dealer installed upgrades during the first few years. Scanmaster, TT 91-93 octane street chip.
PS. P/O replaced injectors. Make & size unknown at this time.
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Remove Erics chip and he'll have the particulars written on it including injector size. Part number is on the side of the injector...it'll tell you the brand. Chart is below.
http://users.erols.com/srweiss/tableifc.htm (http://users.erols.com/srweiss/tableifc.htm)
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A quote from Jim Ruggles. 'Once you pass 600 FWHP you can expect the webbing to be the first to let go. Girdles are okay for girls, but won't do much for the block other than delay the cracking.'
Keep in mind once you hit 11.5 you'll require safety equipment.
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Jim and Rich here on the board can step in and fill you in on the parts and mods to keep the 200's alive deep into the 10's. They build their own. You have to overbuild them from what your ET goal is. I have more money tied up in this 200 than what my house is worth.
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Who's the best trans builder in the Southwest?
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Southwest what? A lot of these members reside north of the us/can border.
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Southwest what?
Southwest USA.
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I believe Nick Micale would know a builder(s) in that area.
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Depending on where you are you might try don wang(alkyv6 on the big board) at drw trans and auto. He answered a bunch of questions for me so I would use him. I did find a bad thread but it was from 2001.
https://turbobuick.com/threads/drw-transmissions.8525/
I'd still give him a call.
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Don retired
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website seems current?
http://drwtransmission.com/transmission-services/ (http://drwtransmission.com/transmission-services/)
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Well, if that is the case, I don't have a suggestion. Maybe the art Carr fellow at California performance transmissions.
You could always assemble one yourself. I hear Dave Husek has an excellent kit. And has a real good offering in a lock up converter.
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Well, if that is the case, I don't have a suggestion. Maybe the art Carr fellow at California performance transmissions.
You could always assemble one yourself. I hear Dave Husek has an excellent kit. And has a real good offering in a lock up converter.
I have talked with Dave in the past. Nice guy! I'd send him my trans if we weren't so far apart.
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When you decide on your turbo...stay away from LU convertors. Been there...done that. Slip rates are too high unlocked...thi nk of it as a clutch in a standard transmission slipping...and not being able to transfer all the power to the rear wheels. Call Dusty at PTC and spec a race convertor with him. You won't miss LU on the street...trust me. If you need LU for gas mileage...then buy a Honda.
As far as fuel management goes...stick with something you can tune yourself. Don't get conned into these ones that are marketed as self learning.