Kenne Bell 350 Part 2

[man]

The last post I asked if Kenne Bell ever offered a crate engine. I was told this engine was built by KB for Buick. I was told it was a 1970 315HP 350 but by the casting numbers and date code it turned out to be a 1975, not the High Compression 1970 315hp. Well the guy sold me the engine for the going rate of the TA performance intake and Poston BUICK valve covers. Well I took the engine apart today, not really sure exactly what I have in front of me. The rocker shafts are stainless and the rockers are steel not like the ones in my 1970 350. The push rods are adjustable and the exhaust valve lifters are different from the intake valve lifters. The exhaust valve lifters has 6 dimples in the top of the lifter plunger (hydraulic) surrounding the push rod hole. I pulled the heads and the engine has .030 over flate tops in it. I have not pulled the pan yet to look inside but will do that tonight. To be honest I am not very experianced with Buick engines, I am a Chevelle guy. Any of you Buick guys that know 350's that might have an idea PLEASE take a look at the pictures and tell me what you think. I have more pictures if you want to see more. This engine also had a ram air KENNE BELL air cleaner on it, it is on ebay.

[man]

more pics of some of the parts

[bob k. mando]

I was told it was a 1970 315HP 350 but by the casting numbers and date code it turned out to be a 1975



i don't think the specific year of the engine really matters given the build effort that seems to have gone into this. flat top pistons and steel rockers makes me think this is likely to have a pretty hot cam in it and it's probably been zero decked.

a 75 would have the better capscrew rods ( assuming you don't have customs under those custom pistons ) anyways.




and Poston BUICK valve covers.


why would K-B use Poston valve covers?



The push rods are adjustable

yeah, i'm almost certain that block has been cut. adjustable pushrods are one of the most common ways to get around cutting the block and head since the shaft mounted rockers aren't the easiest things to adjust.

[BigRivy]

I think that someone put a decent amount of money in this thing at one time. Probably not recently by the looks of it. Who built it doesn't matter.
The pistons are not true flat tops. They look to be the early style shallow dish that was used up to '70 in the higher compression engines. They are stock replacement cast pistons that have been notched for valve clearance when using a long duration camshaft. This notching was a common option from Kenne Bell, Poston etc. Not offered from the factory or any common parts jobber. The extra expense of those pistons would lead me to believe that it probably has a long duration cam in it. The use of that style of cam would also be a reason to need the adjustable pushrods. To add .100" lift to the cam you have to take .100" off it's base circle which drops the lifter that much further down the hole. This distance cannot be taken up with the travel in a hydraulic lifter. So you would need longer pushrods or adjustable ones. A solid lifter cam would need adjustable pushrods too but I don't think that that is what you have.
The rockers are just the later style. The early engines had the die cast aluminum ones. The aftermarket never, to my knowledge, offered aluminum replacements so seeing the steel ones is no surprise. There are not a lot of options with rockers, buy stock replacements or the super expensive rollers.
I am going to give what might sound like a far out explanation for why it might have two different styles of lifters in it.
Rhoads Lifters.
Rhoads lifters have been around for years. They are what's called a " fast bleed down" lifter. And they do just what that suggests, they bleed down quickly so at low speed they take a little lift and duration off the cam to make it a little more streetable. At high speed they don't have time to bleed down so the cam acts like it normally would. They were sold as a "best of both worlds" kind of thing. Or a "did you buy too big a cam?" "Here's your fix!" kind of thing. I'm sure these lifters are still around, do a search on the web. Anyway here's the kicker that you don't usually see in the adds. You have to be below the compression ratio that your cam calls for by at least a full point to use these and not run into compression related problems. IE, pre ignition or detonation, usually pre ignition. Usually a performance cam grind needs a certain static compression ratio, usually higher, to achieve the dynamic compression it needs when using a long duration cam that closes the intake valve later. Well if you use a Rhoads lifter and bleed 4 to 6 degrees of duration off the closing point and close the valve earlier you trap more air in the cylinder and have effectively raised your cylinder pressure into an area that might cause problems. Looking at the engine you have, I would say that this is what could have happened. The engine was high compression to begin with and when they put in the Rhoads lifters to tame down the cam they bought and they found out that it pinged like crazy and nothing they could do short of buying expensive race gas would fix it. So they swapped out the Rhoads lifters on the intakes to solve the problem. Why they didn't swap them all out is anybody's guess. Probably half a set of lifters is cheaper than a full set.
Then again, it might be just two different brands of lifters.
As stated earlier, it looks like someone put together a healthy 350 at one point using a lot of what was available at the time. It probably had the potential to run pretty good. If the cam and pistons are still good and you are looking to build a high performance 350 I would say you might have gotten a pretty good deal. If you bought it to try to resell the parts you aren't going to make a fortune as used parts, even if serviceable, won't bring that much. The intake and valve covers might bring some fair cash, but used cams and pistons are a tough sell.

[BigRivy]

Man, where are you at in Omaha? I'm from Omaha too. Send me a PM if you want me to come by and look at this thing. I could tell you a lot more if I could see it in person.