This is my main reason for creating this thread. I figured most guys had an idea of what the 6.2 would do hp wise after a cam was installed. 450 plus N/A is the goal with either platform. The cost of buying, rebuilding, procuring additional parts and modding the 6.2 is not cheap. I don't expect the 350 to be cheap either.
As for the sbc heads being made to fit a sbb, not very easily. The sbc has a bore spacing of 4.400" and the sbb is only 4.240"! So even if in you start out with a bare un-machined set of heads the center 2 would only be off by .080" but as we work to the outer 2 chambers they would be off by .080" + .160" = .240" per end chamber! Cutting into 4 sections and removing .160" in between each chamber and welding back together would be the only way to do it, more work than anyone is willing to pay to have done or to do. Not to mention how thin the separation between each cylinder would end up being after that .160" is removed! IIRC correctly the 6 cylinder heads have the 215/300/340 valve layout minus 1 cylinder per head so those would probably need to be cut into 4 sections, moved to configure to the sbb 350 valve layout and welded back together. Or if only one cylinder is welded on, the custom cam deal with some offset lifters like using a TA Rover head mentioned in a previous post would be needed to do. Here is a serious sbb 350/370 build; http://www.v8buick.com/index.php?threads/the-dyno-numbers-are-in.200499/ The N/A numbers are quite impressive with only 8.3:1 compression ratio with a mild flat tappet hyd. cam in that thing! You have to read down to post # 10 where the compression ratio is revealed. If you read the whole thread they got that thing up to about 750 HP and were breaking TH400 transmissions! Not sure why they aren't posting the times of the 370 car on there website? All their other cars have the times posted; http://www.finishlinemotorsports.com/pictures.html
You'll likely be interested in numbers I should have some time in November. Not to put Jim W. on the spot(but I guess I am) he has all my parts etc. for a 350 Hydraulic Roller cam build. The top end will be a ported TA Stage 1 intake and a set of 1970 heads, documented here: http://www.v8buick.com/index.php?threads/buick-350-head-airflow-numbers.323659/ It will have a JW speced hydraulic roller grind. This engine is going in my '70 Skylark Custom convertible, so having a nice idle and vacuum for power brakes was a requirement. I know you mentioned hydroboost up thread, so you are probably willing to go more radical than I am. The subject of stroking it did get brought up, but this engine won't be going down that path.
Thank you! I assumed it would take a nice sized cam to make my hp goal with the 350. I figured I would need to look into other brake options. It will be great to hear the results of your build. Thanks!
Have your block sonic tested . Derek said one of mine that he is building could have gone 4.00 bore but was pushing safe wall thickness for boosted use. So he went with 3.9 bore as it’s a common enough size to have decent rings available. He does have my extra block crank and rods. If he has time maybe he could do another short block. My spare crank is offset cut already and has prankl 6.350 rods.
Great! Since i won't be doing a boosted build I'll add sonic check and possibly 4.00 bore to the list. The more cubes the better right?
It is hit and miss on doing a large overbore on a 350... I suggest taking 3 or 4 blocks into a machine shop and have them pick the thickest one of the batch. Not all blocks can be bored over 50 thou. I tend to do the smallest amount of overbore needed to leave material for strength, cooling capability, and also for future rebuilds.
More cubes , easier to make power. . You will need custom head gaskets. I got mine from Scott Brown at buyracingparts.com. He has a template already. They ain’t cheap but stainless ring. .050 thick. I believe mine are on his website.If anything you should be safe at 3.9 like mine.
Yup block strength has to be there. The cooling has to be good as well. I've seen a bunch of chevelle for sale with cooling issues and big bores lol.
It’s still being built. And will have some block fill. But I don’t believe it will. Have heard of a few .060 over here on the board. As well as .075 and .090 in race use. If it sonic test well you should be fine. The 350 and v6 doesn’t have as much wall thickness issues as the 455 blocks which are basically a big bore 430. I would not rule out using Honda journal rods (1.889) as the bearing choices are better . The 1.850 bearing is hard . Not sure how well that works on the street. But we will find out
Well if the bearings are hard that can't be good for longevity. Say my crank ends up turned .010 as it's highly likely the engine had been rebuilt before I got it. What rod crank And bearing size would I need to look out for? Thanks guys. Trying to nail down the facts.
Another factor is that the rods people are talking about for the stroker setup are wider than a Buick 350 so they need to be narrowed while keeping the rod centred in the piston bore. Regarding your crank and what amount of stroke can be added: The problem is that the amount the of stroke that can be added is theoretical but it does not take into account the amount of wear or previous cranks grinding that may have been done. The first step is to pic a rod you want to use, next is to take your crank into the machine shop and they can tell you how much stroke can be offset ground into the crank. The block can be sonic tested and you can decide on an overbore. I just bore them all 30 over and skip sonic testing. Next i would have the shop measure up the block and square it off so the deck surfaces are perpendicular to the main crank line. Then they can give you an exact measurement for the deck height as you will need that to order custom pistons.
