Funny you ask - As we were talking about recently in a PM, I have to catch up on newer cam technology & also been reading through the 350 cam thread you started. I had such such great success w/both the KB MK 2H & C118 that those are my benchmarks with respect to 350 cams and was wondering why those grinds aren't still used but figured there must be better these days. I've even considered having (or maybe tweaking) these grinds & having them custom ground but again I figured there must be better to be had. Is that really the case? Even my Mark 2H combo was making great power @104 MPH in a very basic setup even though the ET didn't show it. I think w/4.10's or maybe even an M20 it would've been (a lot) quicker. Also worth noting but obvious from below is that KB used the same grinds for the 350 & 400/430/455. Notes are not mine - IIRC @LARRY70GS posted this in another thread. I don't want to muck up Jan's thread anymore than I already have here (sorry Jan), but maybe worth discussing in your cam thread the pros/cons of these grinds vs. say TA & Crower which seem to be the 2 most popular off the shelf cams for 350's. I'd be interested in the feedback from some w/more cam knowledge as to why the newer grinds are better.
Very interesting, from what I can tell cams like the KB118 are about as big as can be useful in most 350s. The head flow, dual plane intake, and compression ratio really limits the RPM range to 3000-6000. Now that we have the head flow (alum heads, and sounds like your ported irons), the key is the intake manifold! A single plane on these engines really helps move the power range up to the 3500-7000 range if the engine will go there, and if the cam will allow. Using nice rods and pistons with valve reliefs opens up options. Fuel types help a lot too. Heck I will be running on E-85 with 10:1 plus turbos and the tuning window is way larger vs other fuels. It will be cool to experiment with the high compression engine I’m building too, with about 13.5:1 and the right parts it should be a monster. I will say that roller cams are a big jump up for the street/strip crowd. Better low rpm manners and still great high rpm power. That being says I’m not sure that a roller cam would have much if any advantage over a big solid cam at the track. I’m going to try this cam, it should at least sound nasty with 13.5:1 and open headers! The heads will be ported to the max.
My first engine was more of a sequential build up and the 2nd was a complete rebuild basically adding the C118, heads, and compression all at once which I figured all together were worth 1 -1.5 sec. I often refer back to the KB 350 build from the 1980's and just read through it again tonight. I hadn't actually seen it before I did 2 my builds in the late 80's & again in late 90's but my results largely mimicked what that build entailed wrt the best bang for the buck being in the cams, heads, gearing, and for whatever reason (I suspect being able to keep the engine in a better rpm band), the switch they made from the automatic to the 4-sp. made a dramatic difference and I think is one reason why my old car was so fast from the very beginning. I'm embarking on two 350 GS Restorations now. One is another factory 4-sp. & the other an automatic which should be interesting. Unfortunately both are basket cases so it'll be a while. I'm thinking the only way to really get performance out of the automatic (& keep it streetable) is to go to a 4.33 or 4.56 and a 200-4R. As was pointed out in another thread, with the MPH that KB achieved on that build, it was making the HP to go much quicker. Would've been interesting to then start doing suspension mods/tuning once the drivetrain was maximized. It'd be interesting if Jan would be willing to share what suspension mods/tuning he did on my old car to get that ET. I do see it sits noticibly higher in the rear than when I had it. I suspect whatever he did was probably worth .75-1 sec. as I think the car as-is (or was), with engine tuning only, was probably capable of mid/high 12's. Life got in the way and I never ran it all that much after the resto/engine. There wasn't a lot or anything super trick to the builds really but they got me hooked on the potential of 350's. I can't wait to build another one but the question of those old KB cam grinds and how well they worked has been nagging at me.
That KB 118 cam is kinda like the Lunati I am running now 507-502 1.55 r 230-245@.050 116LSA the GS club had this cam making 390 hp with ported heads and 10.1 comp. Cam starts to give up at 5900 rpm Definitely less power up top compared to the 510 cam I used. The Lunati only got to a 13.31 time as I cannot unload my suspension since it is all set up to handle in the corners, thing is very tight I have big sway bars on it and I am not going to mess with it. Thinking about changing this cam now that I have the SP3 Thinking solid lifter not going roller unless I rebuild everything this just something I have a thought on for now. TA has a nice solid so does Crower I noticed Schneider has some nice solid lifter cams too Just got to pick at lift and duration to make it happen. Looking to get in between the two cams I used. I may have found it..
