So i stumbled on a craigslist add for a buick 350. I drove 2 hours and picked it up, swap some other stuff for it. Guy said it was left in one of his freinds rentals and all he wanted was the stand that was attached to it, so he put on craigslist for best offers. Turns out it is freshly rebuilt(time when own known) but has never been started. Anyways, the lifter valley had a bunch of junk stuck in the assembly fluid so pulled the cam out to clean it. Brand new cam bearings and cam, roller timing chain and front cover has ta seal. So i pulled pan and cylinders have hone marks and pistons are new. It says SP 78 stamped on the deck so..... Sweet score for my GS350 car. So cleaned everything up and found 113207 and 372183 on back of camshaft etched like most new parts. Says USA below numbers. So anyone out in the world might know how to find out what camshaft it is. Tried comp cam part grind search and nothing... Plan on calling crower and ta, but maybe someone here has some better ideas. Thanks for the help,
The crower is a good choice . If you have a head off you should measure the depth the piston is at top dead center and measure the dish cc. . If it has aftermarket Pistons the "SP" designation means nothing. Piston depth of .060 is stock for that year in most cases. 10 cc dish in piston is about correct for the hi compression piston . With a .045 thick felpro gasket and a 58 cc head you can expect about 9.2 actual compression. So compression may fall short if your wanting a TA 310, TA 413. Or other larger cam needing higher compression. You can get a custom grind from Scott at buyracingparts.com. But know your plans and engine specs. May be a stock grind . Is there any other stamping?
Some casting numbers on the shaft is about it. I planned on taking the heads off and looking for a number and measuring cylinder bore. Has 472 heads with seals on intake/exhaust so they have been rebuilt. Im looking at just getting a tame sbb that will cruise with AC on. Nothing above 350hp ish maybe. I will look around at cam again and see if i can find anything else.
Sounds like a great score! Like Andy mentioned, you need to see what pistons you have and how far in the hole they are and what cc dish they are or you could end up very disappointed at right around 200 HP if that with no low end torque. If it measures out to be low compression all is not lost, you will have options like using the steel shim gaskets and or having the heads milled to bring compression up to a more realistic useable ratio. IMO there really isn't any reason to run less than 9:1 static compression to run pump gas, unless the plan is to run a really small RV type cam which could bring the dynamic compression to high. That's the bad part about getting something like this, you know absolutely nothing about what it has in it or what was done to it, so you won't know what to expect when you start it. It could end up being 12:1 compression intended to run race gas for all you know. If you install that in your car and try to run pump gas you can do some damage to it before you know it from detonation. In other words it is best to know what you're dealing with to make the best out of what you have.GL Derek
No the junk is all the dirt and hornet nest that was stuck in the break in lube. They had a bunch of shop towels in lifter valley and tape off the intake/exhaust ports. Then piled stuff on top of it so the valley was full of dead bugs, hornet nest, shop rag fuzz and everything else.
We all know just how weak those factory 350's were on the low end torque, right? Just an FYI for those who didn't know, all the sub 200 hp figures we see for post '72 350's were SAEnet figures, not flywheel. It makes them appear weaker than they are (on paper). Hp is the real weakness of a stock low comp Buick 350, but the torque never was. Even for built 350's with higher compression, torque doesn't soar that much more than a stocker. You have to really pull the air through one in order to exceed much beyond 400 ft. lbs. flywheel. Figures of 365-380 ft. lbs. is typical for a 'hot rod' street/strip Buick 350 with higher compression. The lowest (flywheel) figures seen for even the low comp engines was 350 ft. lbs., and that was with a tiny 2 barrel. A typical stocker with 9.5:1 (true) comp will see around 375 ft. lbs. give or take a few. This holds true for any N/A Buick 350 I've seen (stock or not) with power peaking at less than 5,500 RPM. Spin them up to 6,000+ and you'll begin to see closer to 400 ft. lbs. --and even beyond that the higher your powerband goes. (EDIT: even Jim's well-built TA 212-350 build with ported heads and large tube headers (tuned on a dyno) produced 398 ft. lbs. @4100 and 349 hp @5200--if memory serves...and is an excellent example of what can be expected out of a professionally built and tuned Buick 350 with well-matched parts. He used a Qjet 750 and said that the engine wasn't even close to taxing the carb) These are realistic figures, not over-inflated or exaggerated claims (in either direction). Another FYI, for a cam with peak torque @2000 and hp @4000, the smaller Melling cam has an incredibly early IVC point of 50*, making 8.5:1 true static require premium 93 octane. With static compression ratios ranging in the low-mid 7:1's requiring 89 octane plus! It's all relative, and the real weakness/disappointment comes from mismatching parts. The proof is out there already. Just a friendly reminder is all so as to clear up any potential confusion. Gary
I think I have a fever or something. Sometimes a 'rule of thumb' is ok to go on, but there will always be exceptions to any 'rule'.
??? It does not seem likely that cam would determine peak torque @2000 and peak hp @4000, that's unrealistic. Those rpm points are when the port reaches a certain airspeed (at peak tq.) peak hp is when the port is close to choking out, as related to the dimensions of the cylinder. The cam can sway the curve... fatten it up below peak tq. with an elevated cylinder pressure curve, but the peak would still be close to the port's determining rpm via airspeed. I'll agree that if one forgets about the #'s and the factory ratings that the sbb350 was impressive from the factory, and if the dimensions and components vary from that the performance will suffer.
The 2000/4000 is what it showed. Not a real-world dyno of course. If we disregard those numbers, the point was that an intake valve closing point of 50* requires much less static compression (considering the Melling sbc-11 cam used in this example), indicating that even a 'low comp' Buick 350 would have respectable torque using this scenario.
You got me Gary! I forgot to mention if the unknown cam was to large that low end torque would suffer. Are you saying the numbers he posted are for the Melling sbc-11 cam? I did not know what cam he had when I posted, and it really doesn't look clear from the posts that anyone has deciphered the posted numbers for the cam yet. No need to roll your eyes at my post until you understand what I meant. I'm out, Gary can clear up any questions here from now on. Its all yours Gary. :TU: Derek
Well low compression is where this engine was heading. Took a head off to find out that they are actully KB pistons 0.040 over and part number 1731. Compression height is 1.805 and stock deck height so figure about 8.2-1 with the bore on 58cc heads with the felpro .041 headgaskets. They sit pretty low in the hole. I would still like to figure out what cam it is and see if its worth running for a driver or if its actually mismatched parts. Crank has also been turned 0.010 rods and 0.020 mains, did measure bearing clearence yet. My original plans was to put my extra LS1/T56 in it but since i found a 350 and i rebuilt the th350 that was in the trunk to keep it in it half way stock form. 350 doesnt look bad besides being dirty on the rebuild, so i plan on tearing it down and hot tanking and reassembly. It had a few mud dobber nest in timing cover and oil pan.
The eye rolling was intended in the best possible manner, not confrontational. In the real world (face to face) I tend to say sarcastic stuff and then laugh immediately afterwards or roll my eyes while saying it in an obviously humorous manner. It conveys the thought and emotion much better than some words on a computer screen. Nah I didn't bother to try and look up the cam (doh) I just wanted to go off on my own selfish tangent. Boo on me. I just wanted offer a friendly reminder of intake valve closing points and DCR. I may later, as for now I'm out of time. grrr. All this damn job stuff and responsibility is a real drag. lol Though one last thought: some of those old cams (OEM numbers) may be discontinued. I know Federal Mogul used to make a smaller cam than the cs647, but I guess they figured that one was good enough for all Buick 350's....and we all know just how in demand those cams are lol (not) I'm starting to lean more toward the Melling sbc-5 cam anyway, since its later IVC point would suit flat top forged offerings better for street gas. (More on that later on maybe if I remember/have time/feel inclined) Gary
You can use other aftermarket cams with earlier intake closing for better DCR (such as the Crower level 2 cam) to avoid any machining and get better power, depending on your intended goals for this engine. Others here will have advice on this too. Gary
Seems to me with slugs that far in the whole quench would be way off. With them being .100 in the cylinder at TDC, seems deep and not have good squish. Now i am not a very experienced SBB builder as this is my first one but if this was another GM or LS, no way as .100 way above average. But is it normal for a SBB? As for the cam Im not worried. If i buy a new cam i buy a new cam. I was more curious as what this one was in it, but if i can not indentify it i wont use it because i know nothing about it. It is probably a stock replacement elgin or Melling. I would rather machine it and it be healthy and run great than be a doggy turd. Do it right first time instead of wrong two times. So should i have it decked and get that piston height better to bring that compression up, better quench, and match a cam or reassemble and run it as is? What would you guys do if it was yours?
I suggest switching over to Pistons with more compression. If your comp height is 1.805 you can assume about 7.7-7.6 compression ratio. The 76-80 engines had these Pistons at .090 down hole. 3.0 v6 Pistons can be used at .090 down hole but will be up around 9.8-9.9. As they are flat tops. I think they where #1734 .Or 340p if they are still available in.040. I'm guessing that was a engine builder kit with the cheapest parts so the cam I'm going to assume matches the 76-80 Pistons. you could use the cam you have. Or several other choices with higher compression of the 3.0 flat tops would be the TA 290/ta284/ or the crower level 3 with retard. Or go more aggressive with a ta310/413 or Scott brown custom.would need all the good stuff for those. But that's just my thought since I have had the 140 hp 7.6 compression engine and was not excited.
It depends on what you want to use it for. Obviously, all-out racing won't net record-setting results using the existing parts, but for a cruiser with some street pep, it'll be just fine. "Fine" being subjective. Once you're used to a high-powered engine or a higher reving one, going back to stock or mild seems like several steps back until you get acclimated to it again. Similarly with increasing power or powerband over what you were previously used to. Sitting that far in the hole is typical for an engine with no machine work and 1.805 CH pistons. (there was a debate over this a little while back, so I'm going to be kind and tread lightly on this subject) Those KB pistons should have around 26cc dish size, which means you'd be sitting at ~7.54:1 static using the composite gaskets (.045 thick, 3.9 diameter) and no machine work, with 58cc heads and sitting ~.030 over deck height book specs below deck. Boring an engine will increase compression a bit, since you're pushing more swept volume into the static volume area. (above calculations are @.040 overbore) With a 58*@.006 IVC point cam such as the Crower level 2 cam (installed at default position of 4* advance), dynamic compression would be 6.36:1. This is suitable for regular grade 87 octane pump gas, or 89 octane if you go aggressive on the timing. Not terrible, but not great either. An educated guess on iron manifold power would be somewhere around 360-370 ft. lbs. and 250-260 hp flywheel. If you used the Melling sbc-11 cam with an IVC point of 50*, dynamic compression would increase to 6.66 (a full 1/3 compression point), bumping octane needed to the next grade, depending on what all was done. The Melling sbc-11 and the Crower level 2 cams would have similar powerbands, give or take 100 RPM or so. All this is my opinion, based on research and experience. As far as no quench, the Buick 350 has small combustion chambers which helps to alleviate (but not eliminate) the need for it. With open head chambers, quench will be non-existent anyway, so it doesn't matter how far down below deck the pistons sit... With everything sitting as is, you could try to mill some off your heads to try and get better compression (still using an early IVC cam) for use with premium pump and squeezing the most torque you can get out of it. Let me try to find that part number on your cam to see exactly what it is. EDIT: so far nothing but obscure parts for cadillac, nissan, and a lawnmower lol, not camshaft related. Maybe it's an obscure batch number that wouldn't be listed on anything you could find on the web (or at least not very easily). I could invest more time digging deeper, but unfortunately, time is a luxury for me at present.
I'm going to disagree with you Gary on a 6.7 dynamic engine having 260 hp or anywhere near 370 lbs of torque when we have seen it dynoed 370 lbs with level 3 cam and 9.7 static with 4 retard. Can not be that much increase from cam and that much drop in compression I would say more like 175 hp-280 lbs torque. Based of 1980 model year 350 with the what those know Pistons where designed for. Jump my opinion but seems accurate. Using 3.0 v6 flat tops meting about .090 below deck zero dish and about 9.9 compression with a cs647 cam retarded 2 degrees that could produce 280-300 hp and 370 lbs in my opinion. But premium fuel needed.
