I had the crank in my old build cross drilled, but that crank is junk now. My spare crank is already 10/10, I'm just curious if cross drilling is better/necessary or go fully grooved mains. OORRRRR, is any of this necessary at my level? My concern with fully grooved mains is the reduced load capacity of the lower shell. Cross drilling doesn't bother me, I don't think its going to weaken the crank, but is any of this necessary or is this stuff old school?
Ethan, he will be running the new Molnar H-beam rods with his new roller cam so he doesn't have to set a rev limiter to 5,000 RPM anymore! Mark, if you think your new cam will still be pulling @ 7,000 RPM then you may want to consider it. But with hydraulic lifters your RPM will probably be done @ 6,500 RPM lifter rating? Unless,..... the TA 350 lifters are the high performance short travel high revving hydraulic lifters? Or you swap in a set of solid rollers, you can do that on a hyd. grind but not vice a versa, you would want around .010" of lash on a hyd. cam with solid lifters and let the revving begin! Derek
True if you gonna swing it harder I would look into oil mods. On the stage 2 it was running 4.78's it was having issues due to the increased rpm. They were hanging thier tongue out on the big end,No harm in doing it obviously
That's the one thing I don't know about the cam, is "when" it starts working, and "when" its done. Tim at TA said these rollers are uncharted territory for the 350's It will be fun to find out I'll ask Michael @ the machine shop about cross drilling. I wanna be safe oiling wise to 6500 rpm. The suction passage in the block was drilled years ago
Machine shop is done with the block as far as line boring. Cyl. bores are ok @ .030 but he doesn't recommend using a "random" 30 over piston, he said going .040 is safer, as long as a ring pack is available.
What about the rest of the oil mods? Like to the main saddles, to the cam bearings through the oil sending hole, blending the main bearing holes to the bearing hole, blending where the pickup hole meets the suction hole, and what about enlarging the pickup hole? And the others in the sticky? It would probably be a good idea to do all of those other oil mods before you even think of double grooved main bearings and cross drilling cranks. If all the other mods are done and crank cross drilled then you should groove the main bearing housing bore in the block and drill your bearings, that would send more oil volume to your rod journals to take advantage of the crank being cross drilled. Like this; Derek
You can get away with going to .030" to .035" over and using file fit .030" over rings if you cylinders will cleanup to that range. If not then .040" is where the next good ring sizes are IIRC. A set of 8 of these would work great!; https://www.summitracing.com/parts/pcr-41847cp-40/overview/ Top ring is a plasma-moly coated steel ring and the second cast iron ring is even plasma-moly coated! 1.2mm(.04724") top, 1.5mm(.0590") second and 2.0mm(.07874") oil rings for a whole lot less drag than the 5/64"(.078125"), 5/64"(.078125"), 3/16"(.1875") factory style rings! Here is the reference list I looked at to find those; https://www.summitracing.com/search...geSize=100&SortBy=Default&SortOrder=Ascending There are probably more sets than what Summit has listed so ask S. B. if that is where you're getting your IIRC AutoTec pistons from. Derek
WOW, good info and links Derek, thanks! I'm sorta leaning towards the Total Seal TS1's IIRC, the suction passage was all I had drilled, DAMN, it been at least 20 years since I've used this block
He had called me a week ago, I just got back to him today, and I forgot to ask, I'm going to stop by after work this week and ask, as I'm sure that's important along with the rod length, being the Molnars are a bit shorter than stock.
Summit is good for an easy quick reference, is so easy to look that kind of stuff up there. Make sure you get the standard tension rings if you go that route, unless you plan on using a vacuum pump of some sort to suck out the pressure in the crank case if you want the low tension rings. Plus those don't have the plasma-moly face so they'll take longer to seat than the other ones with that coating. But the second ring is gapless so not a bad way to go. Get this set with the 20 lb of tension; https://www.summitracing.com/parts/tsr-t7255-65/overview/ Unless Scott B. if that's who you're going through has a better option for the 3.840" bore size? He is pretty good about that, there can be even better ones that the v6 massive boost guys use that Summit isn't listing? I still like the other set better even though they cost less because the top ring is steel and a bit thinner for all 3 rings for a bit of less drag than the "gapless" set and the plasma-moly coating will seat faster and are easier on the cylinders with the coating. I read a comparison of the gapless rings vs. a good set of performance rings years ago but for the life of me can't remember the results of that comparison! Anyone have an opinion on the gapless rings vs. the non-gapless, if Mark doesn't mind that question here? And yeah, make sure all the oil mods are done before the machine shop does the finale block cleaning and starts installing the oil plugs. Get the front oil plugs tapped and get the screw in plugs from TA, the one for the passengers side IIRC needs to be thinner and TA sells the one for that side thinner. Derek
On the main Jurnals that need to be double cross drilled that makes for 4 nice sharp edges inside the Crank where they meet/ intersect, and we all know how well sharp edges are at starting off a crack in highly loaded areas! I'll take a chance on having too little Bearing surface on my motor then chancing snapping the Crank all of a sudden at 7500 rpm from a crack that a Mag check can't even detect, only X Ray!!
Id welcome a discussion on gapless VS standard rings! I ran gapless on one of my 350 builds years ago, yes the leak down was 2% or less when tested, BUT that was a static test. I'd like to know how much leakage standard rings exhibit in a running engine VS gapless rings. My theory is, power wise, theres probably not much difference, because the duration the standard rings have to "hold" pressure is minimal, meaning theres not a lot of time for pressure to escape in a running engine. Is my thinking off?
IMO the idea of a gapless ring is a no brainer if you are serious about a street/strip engine. If you are going to spend big $$$$ on everything else why skimp on rings if you are looking for the best performance? Probably the gapless rings are worth very little HP compared to standard rings when NEW but how are they doing after many runs or more importantly after thousands of miles of street driving? Then tell me how they compare. If somebody has that dyno comparison that would be interesting. If you rebuild your engine every year then maybe it doesn't matter if you run gapless. I've been running the Total Seals since they used to include a piece of candy in the box and it is a no-brainer to me. TA has BBB short travel hydraulic roller lifters so they may have them for the SBB. Hopefully that is what you have if you want 6500 out of them. All I know is they cost more money but I'm serious about getting the maximum rpm potential out of my (455)roller. It seems I see the "that's not really worth much power" bandied about a lot but a difference is made when all the little stuff adds up.
Hey Mike, I believe the roller lifters are the "standard" rollers. TA 1412-350...$425.00 I am definitely going with gapless rings. I too had thought of the "it all adds up" saying, and since I'm at where I'm at with the engine, now is the time to "add it all up" and include it in my build. Another thought crossed my mind, if I run my iron heads for now, I'm not sure how well the intake will fit as the iron heads were cut on the intake side to compensate for the .050 cut off the deck of the other block. Me thinks I better focus on one issue at a time Deck height and pistons right now.
That's why they make these gaskets in various thicknesses; http://taperformance.com/proddetail.asp?prod=TA_1712 Just get the sbb AMP valley cover and use the composite gaskets or cut a valley pan gasket to fit under the composites. $35 from AMP; http://www.automachperf.com/oilsystems.html Derek
Correct me if in I'm wrong but I think you still need something under there so the PCV valve isn't sucking in oil from under there, that's why the valley pan is there in the first place isn't it? Derek
