A sweet sbb 350 combos if anyone is thinking of building one.

Block is off to machine shop in the am. Crank will be taken to the 1.889 + the extra .090.
Once the block is sonic tested, if it can it will bored out to the 90 over if not 60 over then.
Might as well go BIG

 

Just remember you may need to a different head gasket if you go with a large overbore. Personally I am good with 30 over, it leaves room for another rebuild or two if needed down the road. My thinking is to leave as much material in the block as possible for strength, I only bore as much as I have to to get a good surface.

At least now with these gaskets you can get a larger bore gasket option:

http://www.buyracingparts.com/gaskets/buick-350-severe-duty-head-gaskets.html

 

Just sonic test block. With Johnny running .075 and .090 overbores and my .100 over bore with a block sonictested up to 4.00 bore , block should be safe at .060 easily.

 

Go big or stay on the porch!! LOL

Sean, if you plan on re-using the expensive custom turbo pistons if they're still good and you run out of clearance for another hone, the pistons can be coated to make up the difference.

If you have to get new pistons, all your race prepped block would need is a toque plate re-hone and new custom pistons ordered. Usually a re-hone for new rings doesn't take that much material out of the block and if its a well maintained engine there shouldn't be much wear in the cylinders anyway, it is a Buick after all isn't it? Plus if the block is good to a 4.00" bore and you're only taking it plus .100", how many rebuilds do you need!!!? LOL How many sbb 350 with a butt load of miles on them have you taken apart to find they only need a re-hone to re-use that block? And with the cylinders opened up they should still have the same wear properties as the stock bore did, I would think so anyway, I have never heard of any manufacturer heat treating the cylinders of their blocks.


The biggest plus yet, with all the sbb 350 engines you have, if you like the way s big inch sbb ran and you needed another block you just take another one off the shelf if it can't be re-used again because your flat tappet cam failed and scored the cylinders bad enough to call for another .030" over which it doesn't have because its maxed out already.(one cure for that would be to spring for a roller, lol)

Sean, the Mackley Pro-charger sbb 370 could of been much more cubes with a sonic test and custom pistons because they stroked that thing to the max for the rods they used, all the way to 3.990" stroke!! If they wanted to max that thing out they probably could of taken it in the 380s or even 390 cid range.(glad they didn't though because of how it embarrassed the BBBs without a jock strap as well! LOL) Just imagine the power potential of a sbb 401 CID engine with the light weight heads and with boost!!!

Sean I have a question for you, have you ever sonic tested any of your sbb 350 blocks? I have mentioned it before but is worth mentioning again, in your book it would be some GREAT info to know which year blocks sonic check thicker to know which ones to try and get to make a big inch sbb.(kind of how the BBB guys know that the "blue" blocks are supposedly the thicker blocks)


Derek

 

For the non-power adder engines I agree, large cubes is where it is at... I will stick with my small bore, stock stroke engines, each to their own. The problem with starting over with a different block instead of a rebuild is the cost is a lot for all the machine work, block girdle etc, unless you do your own machining it is best to re-use the same block once you invest in getting it all dialed in.

Sonic testing is on my to-do list, I have a whole bunch of bare blocks that I can have tested to see if there is any certain years that are better than others. I do not even sonic check, I just bore 30 over and call it good. You can see that some blocks have more core shift than others, they are all over the place. I am sure some engines could be bored way out and others only 60 thou.

If I was not using power adders I would chase cubic inches, but I like the challenge of doing it with just 355 cubes...

Look at the SBC builds these days... 500 HP smallblock Chevy but its 430 cubes LOL

 

Unrelated, but I remember hearing that Duramax blocks have heat treated cylinders near the top, maybe?

Lower tension rings help bore wear issues, but if you stay in a "safe" rpm range and away from catastrophe (more like moment of force or block flex) it would be very hard to "wear out" a bore on a performance build.
You are more likely to replace other components from fatigue long before you wear the cylinders out, such as valve springs, flexplates, etc.

 

Not sure where you got that info from BUT that is not the norm with over 400 cubes and a sbc. I have built 383 sbc engines just under 600 HP that are N/A and run on pump gas. The sbc 434 I did was just over 670 HP and runs on pump gas. N/A those engines are breaking Ford 9" rear ends, killing powerglide transmissions and TH350 transmissions(the 383, the 434 killed a TH400 so far)

Don't get me wrong, I'm not endorsing sbc engines, just sayin' they can make some power if that's the platform you want to use.

So what's the challenge? Its NO challenge when you're boosting. Especially turbo boosting, a story in a older HRM had an article of a totally stock GM 4 cylinder that made just over 100 HP N/A and they put a huge turbo on it and the engine made 1,200 HP!!! They cranked up the boost a bit to make the engine make 1,300 HP and the cylinder head broke into 3 places, they found the limit for that stock engine I guess.

I would agree with you about "a challenge" if you were NOT using boost with just staying with 355 CID with your sbb build. But hey, basically a sbb 350 with turbo boost is a GN engine with 2 extra cylinders pretty much and those little things can make some power!! So with 25% more cylinders than a GN engine there is a WHOLE lot of HP potential!! But could be even more with a larger bore and an even longer stroke.




Derek

 

I'll agree with both mindsets to a point.

Limits will be found that suggest maintaining crank overlap and wall thickness, and efforts towards airflow and max strength.
It would be neat to see just how far you could pu$h one.

 

I did not mean that 500 HP was the max you could make with a SBC I was just poking fun at the huge cube smallblocks because they really are not small at all.

Part of the reason I am sticking with stock bore and stroke is because I find it interesting to use the engines in their designed specifications not a completely modified design. I also love that I can gain data using a stock shortblock and then swap in a built shortblock and have the same fueling and ignition needs without starting from scratch.

I think the Buick 350 is well designed from factory and want to see what we can do with stronger rotating parts but nothing else changed.

I would love to see someone do some huge cube stroker stuff, it would be super cool to see...

 

Sean, you need more than one vehicle with a sbb in it so you can play with your sbb engines both ways! You dropped the ball when your truck needed a new engine, you could of done a big cid sbb for that! I'm sure with all the sbb 350 blocks you have that one of them would sonic test as good as the one Andy has that would be good to a 4.00" bore. Your truck could be sporting a sbb 401, 4.00" bore and 3.990" stroke even topped with one of those new FI-Tech systems. 9:1 or even 9.5:1 would be all you would need for a truck engine with gobs and gobs of Buick torque.

The Mackley Pro-Charger build proves you can run the nascar take out rods with a 3.990" stroke without any clearance issues.(no clearance issues that were mentioned in that thread anyway o No: ) They used Wiseco v6 turbo pistons that were 3.840" with a 3.990" stroke to get just under 370 cid. They had to open up the bore diameter on the wrist pin for the Wiseco pistons, not sure what they started with though I would assume they started as the typical sbc size of .927" but not sure? I think they moved the wristpin hole as well when they opened it up, can't remember for certain its been about a month and a half since I re-read that thread.



Derek

 

I think once some more people actually complete the large bore and or stroke combos and we can get some more facts about the limits and what works then it will be easy to repeat those builds. I have no interest in a sbb in my truck the LS 5.3 is amazing and I have a 6.0 to swap in if I ever need to. I'm hooked on the LS engines, won't use one in a Buick but they are amazing.

With all the projects I have on to go I have no interest in chasing stroke or big bore diameter, but someone else might. The place for the cubes would be for a NA build for the new heads.

I am surprised more people don't have bottom ends with good rods built for the new heads, but eventually things will pick up momentum.

 

I was talking about your Gen. 1 sbc truck that you put a boring crate engine in. o No:

IMO the only thing special about the LS engines is that they come from the factory with a roller cam and coil per cylinder spark and MPFI and the firing order to reduce internal harmonics. All those things can be adapted to the older engines and would level the playing field to make an opinion on what is really better.

If you ever put one of those engines together it would make you wonder how they stay together with 8mm rod bolts which would be the equivalent to 5/16" rod bolts. They went from 3/8" to 7/16 aftermarket in the Gen. 1 engines because the bigger bolts are stronger with a lesser failure rate. I think it has to do with the firing order that reduces harmonics that let the puny fasteners in that engine hold it together?

Sure an over 100K mile LS engine from the junkyard can make 700 HP with a turbo, but no guaranty on how long it will last at that level. Don't even think about doing that with a Pro-Charger or roots style blower only pressurizing one side and expect one of those to last very long either. If you noticed, the after market rods have 7/16" bolts in them not 8mm like the factory runs. Look at what your stock bottom end sbb with a turbo did to your 700 HP converter, that tells me the sbb is a better platform to start with than the "me too" engine swap. :rant: ("you swapped an LS in your car? Me too")LOL Rant over.

Some guys are the paint by numbers type and others are trail blazers, its ok if you just want to be a paint by numbers guy Sean, I won't mention it again to you. Was just trying to give you a way to use some of those sbb 350s you have in your life time, I'm sure the girdled block with the billet crank that is only .030" will last quite a few years before it needs to be replaced. o No: You can't take those engines with you, you know.

We'll see what my sbb 300 block sonic tests eventually and if its good enough to make it to a 4.00" bore that's where it will go to, an extra 101 cubes would come in handy. Or perhaps the 72 sbb 350 I have from my convertible will sonic check good enough? What can I say? I just love the way a big inch small block runs!! I may just go with the sbb 350 if TA gets the heads for sale when I have the time to start playing in the garage again, a 401 CID engine that weighs less than 400 lbs could be a fun in my K-5 Blazer 4x4!

Would even be nicer if TA read my older post where I suggested that they cast the new heads so that they can be made both ways as in factory style and stage 2 style exhaust ports that sbc header can bolt to just by the way they machine them so the sbb 350(401) would fit in the K-5 easier possibly having K-5 sbc headers that will work with the stage 2 version sbb headed engine. May have to bend them so the collectors point down a bit because of the extra 1.163" more deck height? But will probably be fine, maybe some custom floor work would get 'r done?

Not enough time when there is $$ around and not enough $$ when there is time!!! But maybe I can make it happen eventually? This new job is kicking my butt though. LOL




Derek

 

For me a lot of it is repeat-ability... If I do a custom setup with huge bore and stroke then it is hard for people to relate my results to their own more mild combos. Where as if I can make some great power with stock bore and stroke then anyone can do it with a more low $ engine. This is the same reason Bill Mah used a stock bore and stroke in his max effort engine... He proved that with the stock engine design with stock bore, stroke and rod length with stronger crank, rods, and pistons great power can be made even with the iron heads and iron intake...

Now if I was looking for absolute max power I would go with an aftermarket block BBC or LS, about 500 cubes and turbos, but I am only looking to make about rear wheel 650 HP in my street car so there is no point in going to that extreme.

I will build a Buick 350 powered 4x4 truck one of these days but it will likely be one of the cast away boosted engines, I like low octane engines for the street so you can use pump gas regular grade... Been playing with my Range Rover with the 4.6L and I think it would be super fun with a few PSI of boost.

I do have the 75 Regal and it will get an engine swap at some point but I am leaning towards leaving the stock engine in place and adding a single turbo to that.

All that said if I had all the machine shop experience that you do I might be more likely to think outside the box on that aspect but I am not going to re-design the engine myself and hope it all works out.

 

Derek, I agree with your post (#72).
The Buick would be a natural for a modern controls retrofit.

 

I agree too, I would love to see a really nice modern controlled 350 I think it would be fantastic.

 

Oh the old 91, I miss it. I got the crate engine for $1200 new in the box, and that is a reliable engine it still runs strong today. The day after I put the engine in the truck I drove is halfway across the country for work so I need stuff that is reliable for the long term for my daily driver stuff. With the way our weather extremes are here a carbed engine would not be good for a daily driver so keeping the TBI system with GM you want to use a stock replacement engine so that the computer does not get thrown off. The older style TBI are terrible for using with modified engine packages, keep em stock and leave them alone or start fresh with aftermarket EFI. I looked at aftermarket EFI and using a hot SBC engine as an option too but it is a lot of $ and all I needed was perfect reliability and good low rpm torque which the TBI did for me on a low budget.


I sold that truck to my cousin after I was converted to LS power from my 05 truck, once you get used to that smooth running engine, great power, and mileage it is impossible to go back to a SBC in my experience. I was always chasing oil leaks with the old worn out SBC in my old truck, the newer truck with LS engine never a leak, just rock solid performance at the same mileage the old SBC was all worn out and smoking. I will also say the LS EFI systems are easy to work with on the modifications, I use a Blackbear tuning setup and he can e-mail me different tunes over and over while we dial things in. I can record data from the computer while I do chassis dyno runs, highway runs, whatever and he can tweak the tune to keep getting it dialed in. When I put on the ported heads, he sent me new tunes 4 times till we got it dialed in fully. Remote tuning is awesome, and low cost compared to even just buying an aftermarket EFI system. I think I paid about $3000 for my whole truck, a good EFI and timing retrofit to an old engine is about that.

 

is Scott Brown the owner of Buy racing? What kind of pistons did you go with? The info Diamond pistons provided me, is not what I thought......
Looking for other forged piston options. My crank has been stroked & once I have the pistons and wrist pins the block will be completed.

 

Scott is who I dealt with when getting my Pistons. Guess he may be owner. Contact him and see what he can do for you . Find out what the back log is as it may be 6 weeks or longer for custom pistons

 

I am pretty sure scott is the owner. You can order any pistons you want from either diamond, Venolia, scotty brown, or ross racing they all have the designs already developed and can do any compression height, and any wrist pin...

What was the issue with Diamond psitons?

 

Told me .787 wrist pins would be a custom pin, which comes with a custom cost. I thought .150 wall would be plenty, but recommends .250 stating the rod is REAL skinny which is going to place a large load on a small area. Just looking for other opinions on custom pistons. So I will just have to shop around. I believe .787 is one of the standard wrist pin sizes..... But maybe I'm wrong