Reply With QuoteSorry...I just come from a different "old" school.
You have a lot of good info Lakes.
Some of it I don't agree with. That's OK. I built my first 428SCJ in 1974. I'm not new at this, and thought there might be some open miinds here.
There's nothing you can say from an engineering or structural standpoint that will justify adding four bolt caps to a thin web block. It's not something I have an "opinion" on, and it dosen't matter how many times it's been done. It's of no benefit. I could go into many details as to why not, but that's not necessary.
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Frankly, I'd rather have a thin web block with forged aftermarket main caps & splayed bolts than a D0VE block with its factory cast caps and staright bolts
There's a lot more about those earlier blocks than just the four bolt mains. I doubt there's much benefit in the extra bolts of those blocks' caps except at extremely high rpm. I would plug the holes and install the aftermarket splayed caps. The block itself (regardless of the four bolts) is a stronger block than the thin web block, and has larger oil passages. I'd rather have a 2 bolt CJ block, and leave it 2 bolt than modify a thin web block.
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I personally know people that have bored C8VE, C9VE and D1VE blocks well past 4.44 with no trouble whatsoever.
IN my post I stated that these are the favorable blocks that could take up to .120" over with bore checking. I have NO arguement what so ever with .080 on these blocks, but that's 100% off from the .160 that I do disagree with. I would be confident that most thin wall later castings can go .06 safely. IIMO .08 is pushing it.
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In regards to the 4-bolt conversions: As I understand it, Ford's purpose for the thick main webbing of the D0VE block (and a handful of D1VE's) was to allow for a simple 4-bolt main cap conversion on the blocks that were modified for 4-bolt conversion. The nice flat machined surface of the thick webbed block facilitates the addition of the factory 4-bolt caps in their existing tooling and set up.
I'm not clear on what you're saying here. Are you saying Ford made these blocks purposfully to be converted into four bolt blocks? That would make no sense at all, from a cost or mfg. perspective. These blocks are left over four bolt CJ blocks that were never fitted with four bolt caps. Ford dropped their racing program in 1970 and that was the end of the 385 series engine R&D and performance run. What was left was just fitted with the two bolt caps, since it was cheaper to mfg. them that way. The thick web blocks are all base CJ blocks. There were VERY FEW D1 blocks with the thick web. (I haven't seen one yet, but I hear they're out there) That's why I say the premium block to have besides the Motorsport block is the 2 bolt CJ block. Then you can definately take advantage of the splayed outer four bolt caps, without degrading the integrity of the block. That is definately better than a cast cap four bolt block.
As far as manifolds go, I don't consider testing a manifold with a ported cast iron head of any kind (especially a CJ head) a significant test of a manifold's flow. Great test for comparison between man's, and probably applicable up to a certain point, but that's not testing the capability of the man. There's also a lot more to a manifold than just flow numbers. There's the issue of fuel distribution and power curves determined by the size and shape of the plenum. The single four Victor or Motorsport with a tricked out 1350 would perform much better than what you can get out of the Weiand. Just because they say it's good for 9000 rpm dosen't mean it "works" there. There isn't much technology in that design, just a way to get eight runners to come together and put two carbs on it. Compared to the GM version or the Dart, or other cast TR's which actually address the issues of flow and fuel distribution in a TR, the BBF TR is pretty whimpy. Check with GM Killer about making one flow enough to feed a hard running BBF. It took a LOT of work, and I imagine it wasn't cheap.
I've been in the dyno room and on the flo bench and worked with a lot of different sheet metal manifolds in pro stock and other R&D. Granted it was a few years ago but the technology hasn't changed that much.
You say the current tunnel rams can support the extra carburation and air flow? What did you find out on the flow bench? Did you compare those numbers to a ported Victor or Motorsport?
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but if the little ol' 512 I watched did 799 @ 6700, why would you think it wont get another 40 HP with more carb and rpm?
40 HP???? What intake and carb are on it now? I don't think you'll get another 40 hp, maybe 10-15, and yes, it would come with more rpm. More carb? Don't know what you're running now. Maybe not. My bet is the Weiand won't support the HP you're at now no matter what carbs are on it. And who's to say the motor will make more hp with more RPM?. It might start to drop off. If you're making 800 hp at 6700 rpm, that's a strong motor. The Victor/Dominator combo will handle a lot more than that at that rpm, so if that's your induction, you either have hit the max of that motor, or something's wrong.
There's nothing personal about any of this. Not from my end. You post a lot of good and useful info. I just read some things that I felt needed addressing, in hopes of a constructive contribution.
great post! Sorry if I offended.
steel
