I am so upset after reading one of the forums on here. I cracked my 882 heads in my SBC 350 and I am about to pay a mechanic close to 1400 dollars to put new heads and a 120$ elgin cam in (I bought the cam). I looked up the casting number when I found out what it was (took a picture at his shop) and they are the 463624 that everyone says are complete junk and prone to cracking (just like my 882's did). They are from a machine shop and have just been refurbished I guess, is there any hope or did I make a really bad decision. I know this was discussed on here a lot in a different thread but I don't know hardly anything about this, I can't even tell from the pics if these are the so called "good" ones, although I assume they aren't. I paid 400 for the heads from him, the rest was the labor. feeling uncomfortable about now. Thoughts on the heads, price for the job etc???

http://postimg.org/image/j163frdph/

http://s2.postimg.org/jt8reyhwp/heads_3.jpg

http://s2.postimg.org/6qi6ssy09/heads_4.jpg

http://s2.postimg.org/uhcidsrvt/valves.jpg

 

462624 350 76-87 1.94/1.50 2.02/1.60 76cc Crack prone
http://www.chevymania.com/

sad to say but i think the guy got ya. not a good choice for heads at all.

 

Considering those castings are also over 40 years old, the technology has changed a lot. Aftermarket iron castings can provide more bang for the buck with lots of bells and whistles right out of the box than the old castings ever did. The cost of aluminum heads is not in the exotic price range any more and can be easily affordable for most budgets.

Even late model Vortec heads are a better option than those antique head castings.

 

I would say, yes, you made a bad decision. Mostly, in doing your research AFTER making a purchase instead of BEFORE.

Unfortunately most of the time, yerbasic corner pats store type machine shops do not take "performance" into account when labeling heads as "good" or not. Their concerns lie elsewhere.

The prices you quote sound about right. Regardless of how crappy or "good" the castings are, it costs a certain amount to refresh them; and it takes a certain length of time, and all the associated parts like gaskets and fluids and whatnot, to change them out. The flip side of that is, if you had a set of "good" heads to hand him, the swap would have cost exactly the same.

If the work hasn't been done yet, STOP!!! and do some research on heads.

Might want to research the cam as well; even more so than heads, not all cams are created equal. A part # or specs would help identify what you got, and that along with a complete description of the engine and car and intended purpose will help evaluate whether it's even appropriate at all, let alone "optimum".

 

You could have brand new world products heads for less than 800 ready to bolt on. They would be thicker, flow better and last longer

 

Basically 76cc smog junk. Sell to someone with a truck that has some cracked ones. They are pretty much 882s, which may be the reason he is putting them on. What pistons do you have? A set of l05 swirlies or some 416es may be better alternatives if only for compression and reliability. As said though buy in for aftermarket heads is not terrible these days.

 

These are fairly cheap, high quality and flow slightly worse than vortecs. Way better idea than 624 heads.

76CC
http://www.ebay.com/itm/sb-sbc-Chevy-Chevrolet-76cc-2-02-1-60-World-Products-SR-Heads-042670-USRA-Legal-/151224676635?pt=Motors_Car_Truck_Parts_Accessories&hash=item2335b1711b&vxp=mtr
67cc
http://www.ebay.com/itm/sb-sbc-Chevy-Chevrolet-67cc-World-Products-SR-Performance-Heads-2-02-1-60-042660-/151224676916?pt=Motors_Car_Truck_Parts_Accessories&hash=item2335b17234&vxp=mtr

 

Thanks guys, the Cam was a mild Elgin Cam. He has already done all the work so no going back. I am concerned that now I could crack them like the others. It is in a jeep CJ7 so I really don't care about crazy horsepower just reliability (ironically). Turbo 350 trans, automatic, headers, quadrajet. Is it true that if I don't overheat the engine that that is the only reason they would crack?

 

That cam is 218/218@.050 and 274/274 advertised... with .450 lift...

It's a pretty crappy cam, but as lazy as it is, it should be more reliable than some of the raunchier, more aggressive modern cam designs. I figure if you're gonna go flat tappet these days you may as well go for a lazy one if reliability is your biggest concern.

Also, those heads may be crack prone and terrible, but they're not cracked now even though they're old and they were likely in some station wagon for 30 years... you should be okay. Just dont overheat them.

 

Looks like you're doing everything wrong with this motor!

 

i think the cam is a decent choice for his low compression jeep. the last thing those heads need is a long duration cam to bleed off more cylinder pressure.

 

274 adv total duration IS pretty long duration. I mean the most popular street performance flat tappet cam is probably the Comp xe268, and that has 268 degrees total duration on the exhaust, and 262 on the intake. This cam has 274, and it has less duration at .050. That's what makes it a lazy cam. You get the bad vacuum and poor power curve of a big cam, but you dont have the area under the curve to make any power with it.

That said, because it's lazy, it will be less likely to wipe itself due to today's flat tappet unfriendly oils. And hej ust wants something that will run okay...

But even a Comp Magnum 280H has a 2000-6000 RPM power band in a 350... This thing is 2200-5200... You can see even in their own advertised numbers how terribly narrow the power range is on it. It starts above 2000 and is done by 5200. That's pretty awful. A factory cam is probably a better choice... it will work from 1000 to 5000 RPM probably.

the comp xe274 has the same total duration, but it has 230 degree @ .050 vs this cam's 218. That's a drastic difference.

http://www.jegs.com/i/COMP+Cams/249/12-246-3/10002/-1

1800-6000 RPM

The price you pay is increased risk in longevity given the way modern oils work... It woudlnt work well in his engine, but technically neither will the cam he already has.

 

advertised duration numbers really mean nothing, and are mis-leading. same thing with those power band numbers, its just a general rule of thumb. every vehicle is going to react different depending on a number of factors.
for an off road jeep, i'd shoot for low end power. btw, how did a jeep post end up in here? lol.

his cam will have good vacuum too. plenty for power brakes. probably around 15-18?

its basically a copy of the comp 218, .454 lift.

 

Seat to seat may mean very little to some with respect to flow and power however they have quite a bit to do with how an engine builds compression. Despite the short 218@.050" numbers it's that 274 degrees and the point where the intake closes which will determine how much compression pressure it's likely to build. The overlap will be greater too (as compared to a cam with "faster" lobes) and that'll pull idle vacuum down.

 

Yup; long seat-to-seat, short .050" duration, and low lift, is pretty much a recipe for a low-vacuum, won't-idle, no leave, underwhelming mistake of a cam. The same kind of thing I've been PULLING OUT of "rebuilt" motors since the 70s to get people's cars to run better.

I just really think the guy that's building your motor doesn't know what he's doing, when it comes to "performance". Pretty much just bolting up a bunch of "stuff" without any understanding of what it all does or how it goes together. Not that he's "ripping you off" or anything like that; only, it could be ALOT better, with very little to zero more money, by making better choices.

Sorry to hear that it's working out that way; definitely not the way for a novice to get introduced to the hobby. It really helps when your first experience is exciting and gratifying. Doesn't look like that's likely.

 

Advertised duration has an absolutely massive impact on the dynamic compression ratio. It will bleed off tons of compression just like a large hot rod cam will. This is why modern cam designs focus so much on more duration at .050 with as little advertised duration as possible. And it is, of course, also the reason modern roller cams are so good and decent modern flat tappet cams are so prone to wiping themselves. With some of these crazy roller cams today you get factory cam total adv duration numbers, but the power numbers of an aggressive aftermarket cam. The total duration is what determines street manners. The .050 duration and lift is what determines power.

http://www.northernautoparts.com/part/ei-cl1785pk

See the 2200-5200 range? Most raunchy street strip cams have better low end response than that.

 

all i was trying to say is advertised numbers can be all over the place.

http://www.cranecams.com/faqview.php?s_id=4

 

Yes there is variance in measurement from manufacturer to manufacturer... but that doesnt change the fact that this cam is going to be terrible at building any kind of cylinder pressure. They aren't as consistently comparable as duration at .050, but they are still comparable. The differences in measurement are not going to make that 274 degrees the same as a real world 262 degrees like, for example, the intake lobe on my xe262, and it shows in the working power band of my cam. It starts making power at 1300 RPMs and pulls to 5500. Some manufacturers take that measurement at .001, some at .005, etc. But that doesn't mean that the measurement methods ARE different, it just means they MIGHT be different, and the variances we're talking about here are consistent enough that they can be used as rough guides for evaluating the aggressiveness of a lobe. This cam design is clearly straight from 1971. That said, you are right, you have to take adv duration numbers with a grain of salt, but they're still valuable numbers to keep in mind and can still be compared when we are talking about these kinds of large divergences.

 

Hey guys I appreciate all the feedback. My lack of mechanical knowledge and trusting my mechanic a little too much were a bad combo. I paid 1500 dollars to have the cam and heads put in (including the cost of the heads) but he also fixed one of my brake lines, put a master cylinder I brought him in, cut and installed a new fan shroud I brought him and he tuned the carb up. BL is the jeep has basically a similar sound and power as it did before. I can "hear" the cam but not that different from before and the power difference is likely a result of both heads not being cracked. The jeep still doesn't run well, he said the quadrajet 4 barrel carb has an internal vacume leak in it somewhere (he holds a cupped hand over it and the idle levels off. So now I may also be giving him 100 bucks for a summit 650cfm carb he had in his shop (225 installed) (it was used but never installed) just to get it running right. I am happy everything works, and the not having the fan shroud is what caused it to overheat and crack heads before (I think). So in staying positive. Thanks again for all the info. If I do this again I will be prepared...

 

Right now it won't really idle in drive (maybe if is warmed up), only in park and that's because it's set higher. It cut off twice on me today going 5 mpg in the parking lot. He says that's because of the carb. Please tell me if I replace the carb it will idle... This time I am asking first.