Pieces of steel in cylinder??
- Thread starter Righty Tighty
- Start date
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I got the Sealed Power H814CP pistons, they were recommended somewhere on this thread as high compression pistons.
Hay, I'm a sad asswipe. I got no problem admittin it. lol But I'm a sad asswipe that's done a lotta stuff to cars through the years and enjoys it......so that means there are sadder asswipes out there. lol
nm9stheham
Well-Known Member
OK that was what I was thinking. But go back an you will see that they are characterized as the highest stock-ish CR pistons.... not 'high compression' pistons.
So, running some numbers, your static CR with these pistons, stock 318 heads, unmilled, and a .028 thick head gasket will be right around 8.2:1. No high. Slap on typical 340/360 heads, and now your SCR is right around 7.8.... right in stock /6 territory.
Now what will really set your lower RPM performance is going to be something called dynamic CR (DCR) which accounts for the cam's effects on effective CR. The bigger you make a cam, the lower the DCR will be and get that too low, and the low end torque for grocery-getting type of driving will go into the toilet. Not good with a heavier pick-up truck in grocery-getting service.
Since you are going to put in another cam, then it is time to look at that and make a sensible choice. You can easily get the low RPM toque LESS than that of a stock 225 slant-6 by getting too big of a cam... and with this lower level of static CR, it won't take much.
So you are not going to use the 318 heads? Is there a reason? Honestly that is not making sense to me. You're gonna have to stick with a smaller cam to keep the low RPM from not dropping out of sight, and with that, the breathing of the larger heads is not of any big use.
For what you want to do with this engine, with these pistons, with the future build coming at some point, and to keep your daily driving torque up, this was recommended: 318 heads shaved to get the CR up.
- mill heads .040" or .050" and use the standard Felpro kit head gaskets and those same pistons; this will push CR up over half a point from the stock level
nm9stheham
Well-Known Member
FWIW on the cam bearing damage: The OP reports that the bad cam bearing wear shown is on #'s 2, 3, and 4, and was much less on 1 and 5. Know that the average valvetrain load bearing on cam journalss 2, 3, and 4, is twice as much as on the #1 and 5 cam journals. So it seems very, very likely that this cam bearing issue came from something jamming in the valvetrain. I personally suspect this drove crap down into the crank. I am not sure how the fishing gear parts got in there LOL
kgip2k
Well-Known Member
I think? He is trying to save some money by using heads he already has??? The 318 heads that he has are most definitely trashed. I will say that the x would be Overkill, they will drop the compression down, but if he has them, and they are ready. Use them while you put the 360 together. But definitely stick with a fairly conseeconser cam.
Those pistons are considered "higher compression" than stock because they use a pretty tall compression height. Gets the piston up in the bore at TDC to help bring compression up. You'll need to figure out your deck clearance with those and also keep in mind piston to valve clearance......you should be plenty safe but keep it in the back of your mind.
Overwhelmed by the cesspool of knowledge this thread is providing. lol
You should know by now, the internet is loaded with tractor and lawn mower engine builders.lol
nm9stheham
Well-Known Member
Well, they are only .015" taller than others..... only an added 0.4 points or so with the lack of eyebrows. Deck clearance is around .067" with a stock LA deck. Still 'in-the hole'. Not 'high compression'.
And yes on the P-V clearance... another thing that goes along with using a smaller cam.
I like the fact that most of us want high performance,and go to town building an engine. What i really like is simple stuff,carb and intake that work well together,proven parts combinations. I take note of these discussions, the experience here in fabo is unlimited.
Yes but "higher than some".
nm9stheham
Well-Known Member
Oh yeah, that's right.... I forgot the crap pounding on the heads! This thread has gone on and on.......
If 'twer me, I would look for some 302 heads. (There were some on RockAuto that were discussed in another thread. I can't speak to the quality or lack thereof for those heads however. There are a lot of questionable rebuilt heads out there.....like the ones that started all of this!) The point being to get the 62-64 cc chambers to help with the CR and the low end torque aspect of this grocery-getter application.
kgip2k
Well-Known Member
I agree... But he is also talking about just getting this one built, running it while he builds a 360, or 5.9, I can't remember. If he has the heads, run them... If not, should have just saved the money on the work on the 318 and put it towards the 360. Same has to be done to it, or if a 5.9 magnum, intake, oilpan, probably be back up and running... Jmo... Then pick up a second one to build. Machine work isn't cheap... Last I had it done.
yellow rose
Overnight Sensation
I don't think the trough was caused by lack of oil. I think that was caused by something shoving the cam into the bearing. All the smearing and such I attribute to lack of oil, if from nothing else than the humongous trough spewing oil like old faithful.
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Or just slam it all together, get a hi-stall and steep gears, and then yur good to go,
which is pretty much what every low-compression teen owner does, or has to do.
With a street 318;I'd take high cylinder pressure and small cam, over low pressure and big cam every single time.
But then, I just wouldn't start with a 318 in the first place,especially not with one as rough as this one.
But if I had no other choice than a low-compression318, I'd run a manual trans, and I would search the world over for more than 4 gears. Mine liked 7 speeds. and 4.30s.
which is pretty much what every low-compression teen owner does, or has to do.
With a street 318;I'd take high cylinder pressure and small cam, over low pressure and big cam every single time.
But then, I just wouldn't start with a 318 in the first place,especially not with one as rough as this one.
But if I had no other choice than a low-compression318, I'd run a manual trans, and I would search the world over for more than 4 gears. Mine liked 7 speeds. and 4.30s.
kgip2k
Well-Known Member
Really? That's it? I know you have more you want to say, and I do like to read the posts, you do have numbers to back everything up.
That makes perfect sense! The reason I wasn’t going to use the 318 heads was because 1) the valve seat dropping out made me unsure of the rest of the seats, and 2) there was a little bit of damage to the #3 combustion chamber around the perimeter. I’ve attached a picture. Another reason I wasn’t sure about the heads was knowing how hot they got (at least the driver side) and was worried about warpage. Those reasons combined made me go in the direction of new heads.
BUT, if milling then is the way to go, then warpage wouldn’t be an issue, and I think the little bit of damage to the rim combustion chamber could possibly be corrected after a mill job. Sort of a 2-for-1.
That still leaves the valve seats. Obviously one needs to be replaced, but what to do about the others? Replacing the others won’t be cheap, but I don’t want to risk this whole scenario happening again.
That makes perfect sense! The reason I wasn’t going to use the 318 heads was because 1) the valve seat dropping out made me unsure of the rest of the seats, and 2) there was a little bit of damage to the #3 combustion chamber around the perimeter. I’ve attached a picture. Another reason I wasn’t sure about the heads was knowing how hot they got (at least the driver side) and was worried about warpage. Those reasons combined made me go in the direction of new heads.
BUT, if milling then is the way to go, then warpage wouldn’t be an issue, and I think the little bit of damage to the rim combustion chamber could possibly be corrected after a mill job. Sort of a 2-for-1.
That still leaves the valve seats. Obviously one needs to be replaced, but what to do about the others? Replacing the others won’t be cheap, but I don’t want to risk this whole scenario happening again.
I would run those heads..........right to the junk pile.
I think righty tighty is doing a fine job for what he is working with. I’ve been following this thread sense the beginning. If I were him I would find a good set of 302 heads and have them cleaned and decked. Run it. I’m not as smart as these guys on here about compression and lift and valve size or any of the language that is used. But I have made some stuff run to get me by. As for the bicker and name calling I think those involved should start a I don’t like you thread or a you an idiot thread. Righty tighty is just trying to buy groceries. Flame if u want.
I cannot agree more.
You don't know if the other seats were done the same way as the one that fell out... The others may be next... I wouldn't trust them...
Either get them redone by a competent machine guy or get another set...
I would recommend getting an old set of 66 - 67 273/318 heads with closed chambers and add 1.88" intakes and 1.60" exhaust valves with a port job, or get a set of reconditioned 302 heads to get the compression up...
Then look for a camshaft with a low/early intake center line and high lobe center to help with the dynamic compression... Earlier intake valve closing with less overlap will help increase cylinder pressure...
Well, went with the remanufactured 302s from Rock Auto. Hopefully I can put that baby to bed and move on to cam selection.
Just Great
You will get that 318 buildt and performing strong with those 302 Heads. Will work out so nice that you will not have to build that gas guzzling 360.
I'll tell you what I would run for a camshaft. It's an OLD tried and true grind. Everybody and their brother makes a version. It's the same as the Edelbrock Performer. Here is Summit's version.
Summit Racing® Classic Camshafts SUM-6900
Affordable, simple and will get the job done. For what you are doing, it's just perfect.
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