Here's the problem with the 1970 GS sbb 350, they gave it an extra 35 HP for the GS hood which has been proven doesn't make more HP because of its placement of the air intakes. The '70 H/C sbb 350 pretty much has the same power that the high compression '68 and '69 sbb 350s had which IIRC was 280 HP. Either they were counting on the extra 35 HP from the hood or it was simply marketing hype? Here is the problem of the sbb 350, way back when the Buick train drivers decided that they wanted to produce a small cid engine that made lots of torque they focused the output of torque and didn't worry to much about HP numbers. The little 215 design took a lot of it queues from the Nailhead technology of back then. They found out when you restrict flow in the heads like on the N/H platform, the result was increased low end torque which for a street engine is king. If you study the 215/300/340 engine block and head designs, one would notice a lot of similarities from the N/H platform such as the stepped diameter cam bearings, skirted design, 2.500" mains for the first 2 of the 4 renditions of the sbb, which IIRC they use the same main and cam bearings as well. The number 3 thrust bearing is the same width as the N/H as well, to bad they didn't copy the N/H's oiling though! Other similarities are of the N/H platform are lackluster flowing heads, heavy rotating assemblies for better inertia to help increase low RPM torque, tall deck height compared to stroke which goes back to making the rotating assembly heavier and many more. They basically purposely built the sbb engines to mimic it to run like as if it were a low RPM big block. When the sbb 350 came into play, they rethought the design and made the heads flow much better for the 350, but they didn't address the heavy rotating assembly and lighten it up with forged rods so the small cid engine could spin up some HP more easily. They were on the right track with the better flowing heads, perhaps the bean counters didn't want to put anymore $$ in the aging platform combined with the up rise of the EPA and the gas crisis? If in the train drivers weren't held back by the above mentioned restraints back in the day then perhaps we would of seen a Siamese 4.00" bore block with a 4.00" stroke crank sbb 401 cid engine with the deck height knocked back down to the sbb 300's deck height! Also with a lightened rotating assembly, bigger valve heads and a raised cam so they could increase the rod journals from 2.00" to 2.100"!! They probably would of built this if in Buick built trucks, this would of kicked a sbc 400 arse! Derek
If you look back at all the hot performance oriented small cubic inch motor they usually are high winding. 6k plus capability right out of the box. the original 350 in my skylark the valves floated at 5300 rpm.. sure that's a solvable problem, but what's that tell you? for what it's worth that was an 80k motor that ran like a sweet heart. when you are lacking cubic inches, you need to be able to rpm to make power, at least in 1970.
Well, that's an easy cop out. I'd hoped to explore the perceived limitations of characteristics that seem to work well elsewhere in the world. I don't appreciate the snarky tone, at least without a technical opinion to back it up. Thanks for throwing a member that gets bashed on at me in a negative way, I suppose that makes it a non-winnable discussion off the bat. It would be reasonable to assume that this platform has not been maxed out by that many skilled builders, being that the few shown here had cast connecting rods and didn't hold together (N/A). I wonder what Kaase, Sherman, or anyone else with a dyno and flow bench could do with one... Unfortunately, the best are getting paid to build things and it's tough for the rest to finance beyond a 'one-shot-at-it' effort. That's the biggest challenge to these engines right there.
I run 32* timing no more, run 5 gal of race gas with 15 gal of 94, and I use Mobile 1 10-30 no issues. I even run the large gears in my dist. and no issues I just looked at it today, haven't had the dist out for 5 years. took it out today to change that intake. all looks good no wear on gears. Ran nitrous, what am I doing wrong...or is it right. and isn't a billit crank and an external oil pump for a race engine.
You bring up excellent points, which usually never get addressed in an honest way without some sort of derogatory commentary, and often off-topic, defamatory, or otherwise collaborative efforts to blacklist and/or slander anyone or anything relating to alternative points of view that have legitimate concerns, questions, or pertinent commentary; with sentences longer than 2 lines being evil and expressive verbiage utilizing the English language being touted as 'technical jargon' being portrayed for those who have the ability to think and read at the same time, when one or the other seems to be a challenging endeavor on an individual basis. You start off by acknowledging you may get flamed, (but never did) and go on to state your opinion which then gets questioned in an honest, direct way. This had the potential for some very good dialog pertinent to the subject title, but was shot down with the following response: So why even bring it up if you refuse commentary about your assertions? This is more of a 'peculiar reasoning' than anything we intelligent posters could ever come up with. In the future, be careful in how you evoke my name unless you come prepared with a utility belt of reasoning as opposed to feeble attempts at ineffectual bandwagon cheap-shots. Otherwise, you may wish to peruse the 'forum posting guidelines' or 'conduct rules' before doing this. Your financial contributions do not include buying special conduct privileges, as could be applicable when examining the behavior of every single website poster herein.
Wow! You need to cool your jets Gary! Your response is over the top & not beneficial to this thread. Everyone needs to get along or just stay out of the sandbox.....
OK, so what I meant is a couple of things, Obviously we aren't talking about the bore/stroke ratio needed to turn 9500 rpm and all that goes with that. As far as those geometric relationships, along with valve/port sizing, valve shrouding, etc....nobody is really pushing power limits here (N/A builds, of course) With all due respect...the circle track builds were a great starting point and if it weren't for rods letting go would probably surprise people what they'd do. Can't wait to see one with nascar take out rods and some stroke to get the piston speed really up there with some legit 290 cfm heads and enough compression to justify E85 or good gas. Other platforms do fine with those traditionally accepted limitations, like a good portion of the Engine masters entries, Mountain motors, or anything else restricted by bore spacing but not deck height or stroke. Port bias aims flow into the center of the bore, things can easily be moved, cut, stretched etc, etc....they are relatively minor obstacles. My only challenge here with this post is to consider the end result of a build done by anyone that truly masters their domain (name drops or others from the board not mentioned). I guaran-damn-tee you if you write a big check to a well skilled builder you will see a serious engine. Many are capable. If we are agreeing that the avg. garage guy buying off the shelf mid-level parts gets a less than spectacular build compared to other platforms that 'happen' to have other geometric attributes...then we are NOT talking about the same things. A well skilled builder will get past those obstacles pretty easy. Still not flaming...
I can respect this. I get along with anyone and everyone as long as the sand isn't intentionally kicked into my eyes while we're all playing inside this sandbox. Fair enough?
I can't wait to see it either. I'm far from a skilled builder, but my plan is set. My Nascar take out rods are on the shelf with rod bearings, and new ARP Bolts, crank is out for grinding, heads are being ported, and pistons will be ordered soon. I'll have my heads checked for flow #'s when they're done. I'll probably start a thread when I get closer.
I know we have new rods avail. but I too am really intrigued with the idea of the Nascar take out rods & a stroker 350
