Cam advice for more torque from 340

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guys lets be real, you cant tell anything by cranking comp.It could be 12-1 with a big enough cam and crank 130.With his posted cam his cranking comp could be correct.
I don't think anyone is doubting the posted cranking compression numbers. He has provided enough data to get a decent handle on SCR; it ain't 12:1 or even 10:1 with the pistons, heads, and head gaskets pictured. Yes, we are assuming the cam is around what he thinks it is but running the numbers with that shows up a lower SCR/DCR than he thought, and his cranking numbers hang with that. They are not awful (like a 6:1 DCR truck engine), but not where they can be for what he wants to do.
 
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Ok. I'm going to order the XE268 or 262 today, the kit with lifters.

Milling might be out of the question. I will speak with my machinist again.
See if you can find out how much he thinks they have been machined; give him that nominal stock depth of .090" in the flat open area if nothing else. There is info around on how to exactly measure the stock head deck form other reference points but I can't find the illustration.

The lower you go with duration, the more careful you need to be with the compression ratio. It might be wiser to wait 'til you get a bit more head milling data. But, you can always adjust head gasket thickness too. Mr Gasket 1121G is around .028" thick, Felpro 1008 is around .039" thick, and Flepro PT5883 is around .050" thick. so you can adjust the final product some with that.

Is the shop checking for flatness on the heads?
 
See if you can find out how much he thinks they have been machined; give him that nominal stock depth of .090" in the flat open area if nothing else. There is info around on how to exactly measure the stock head deck form other reference points but I can't find the illustration.

The lower you go with duration, the more careful you need to be with the compression ratio. It might be wiser to wait 'til you get a bit more head milling data. But, you can always adjust head gasket thickness too. Mr Gasket 1121G is around .028" thick, Felpro 1008 is around .039" thick, and Flepro PT5883 is around .050" thick. so you can adjust the final product some with that.

Is the shop checking for flatness on the heads?
They checked the flatness and said they were good. Since the 1121G is .01 thinner wouldn't that have the same effect as milling the heads or block .01"?
 
They checked the flatness and said they were good. Since the 1121G is .01 thinner wouldn't that have the same effect as milling the heads or block .01"?
Yes, in this case, with the open chamber heads. (With closed chamber heads, you would have to consider other factors....)

Do you think you have the coolant leakage issue resolved? That is my one nagging concern with the heads and block deck.....
 
Yes, in this case, with the open chamber heads. (With closed chamber heads, you would have to consider other factors....)

Do you think you have the coolant leakage issue resolved? That is my one nagging concern with the heads and block deck.....
Coolant issue is still a mystery. I couldn't see anything wrong with the intake gaskets. No indication on the head gaskets or block/heads. No coolant in the oil or valley. I'm hoping that putting it back, properly torquing everything will fix it.
 
scr/dcr whatever, chances are he has 10.5-1 actual or thereabouts .
the intake closing is where crank comp is .The cam he has might not be that diff from what he is ordering.comp and other companies rate their measuring points differently. It might be cam advance/dist advance/tuning where the problem lies.
 
Coolant issue is still a mystery.
How did you determine that you had coolant in your engine? Did you see signs of coolant somewhere inside (I think you answered that above) or did you just notice a trail of white "smoke" behind your car?

On a cool day it takes quite a while to loose the trail of "smoke" (actually vapour) which is nothing else than boiling/ burning condensated water in your exhaust system.
 
scr/dcr whatever, chances are he has 10.5-1 actual or thereabouts .
the intake closing is where crank comp is .The cam he has might not be that diff from what he is ordering.comp and other companies rate their measuring points differently. It might be cam advance/dist advance/tuning where the problem lies.


He will be lucky to hit 9.25:1, especially with the Pistons only out .020 and that thick head gasket and heads that have had a light clean up cut. He's nowhere near 10:1. And that limits his cam choices.
 
I don't think anyone is doubting the posted cranking compression numbers. He has provided enough data to get a decent handle on SCR; it ain't 12:1 or even 10:1 with the pistons, heads, and head gaskets pictured. Yes, we are assuming the cam is around what he thinks it is but running the numbers with that shows up a lower SCR/DCR than he thought, and his cranking numbers hang with that. They are not awful (like a 6:1 DCR truck engine), but not where they can be for what he wants to do.

bingo /\ /\
 
How did you determine that you had coolant in your engine? Did you see signs of coolant somewhere inside (I think you answered that above) or did you just notice a trail of white "smoke" behind your car?

On a cool day it takes quite a while to loose the trail of "smoke" (actually vapour) which is nothing else than boiling/ burning condensated water in your exhaust system.
How did I determine coolant... Keep in mind I am in Seattle.
The exhaust had notes of sweetness to them. One day, it was a cold day, I recorded this on startup.


Shortly after that recording I noticed that the coolant was down a good bit.

Then the smoke turned into this on startup:


Then this after it was warm:


Prior to all this in August this what what a cold idle looked like. Just a tinge of white out the drivers side:
 
Looks like condensated water out of the exhaust to me.
I know the weather around Seattle... been living in Portland for two winters.
Long ago tho.:)
 
Looks like condensated water out of the exhaust to me.
I know the weather around Seattle... been living in Portland for two winters.
Long ago tho.:)
I think the only thing I can do is check that the block is flat and then reinstall the gaskets. Since there were no signs of anything other than the exhaust valves being white on all but the #5 and #7. The plugs also matched the color of the exhaust valves. Pics here: Tell me about my heads and pistons. Pics.

The machinist said that it looks like a lean situation to him when he saw the valves.
 
Here is the plan:
Gasket: Mr Gasket 1121G to pick up some extra compression due to the thinnes of the gasket
Cam: Comp XE262. Their charts show that the 262 produces more torque earlier and more HP later than the XE268. XE262, XE268
Lifters: Will go with the Cam and Lifter kit.

Anything else?
 
have the heads magnafluxed or pressure tested. inspect the cylinders when the pistons are down for a crack. I calculate you will have 9.6:1 with the 1008 gaskets. advance the ignition timing. install a cam at 105*-107* intake centerline. increasing compression ratio 1 point is worth 4% more horsepower-40hp for a 1000hp engine, 14hp on a 350hp engine
 
But worth a whole lot more than +4% for low RPM torque.

9.5-9.6 looks right for SCR, assming the heads have been milled about .010" before. The XE262 installed straight up as ground, which includes 4 degrees ground in advance, will give DCR of 7.9. That is pretty good territory.

The XE268 installed at an added 3 degrees of advance (3* installed + 4* ground in) will give the same DCR, a bit less low end torque but probably pretty darned good, and will be a bit better up top even with the added cam advance.

Running a heavier car might nudge me towards the 268.... it would help keep away a bit more from detonation if the timing got a little off or the fuel bad; heavy loads can put the engine a bit longer in 'danger' territory. And if you are cautious with the ignition timing in 'sneaking up' to the 30 or 30+ degree total range, then you'll be fine with either.
 
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If you are assembling the engine yourself you might want to check the piston to valve clearance. With an aftermarket cam and pistons you don't want the valves to touch the pistons. The easy way is to clay the clearance.
 
OK, I will have everything I need today to start putting this thing back together. I will reference the FSM for the proper torque numbers.

For the timing cover and water pump, any special treatment on the gaskets I should use? I have a new gasket set, I cleaned the matting surfaces up. Should I use any RTV type substance on the timing/pump cover? Looks like it had it on there before.

Any other tips for putting in a new cam, installing a new timing chain, reinstalling the heads, oil pan and timing cover?
 
You'll be glad you checked your piston to valve clearance at this point.
 
Just pulled the cam. Guess what, it isn't a Crowler. Can't even tell what it is. Only marks on it are on the rear. Z016 with three dots.
image.jpg
 
You have to:
1. Get the cam in and timed where you want it. Button up the front and put a bolt in the crank snout so you can turn it.
2. Put in one pair of lifters for one cylinder (with prelube on the lifter faces and lobes; I would recommend moly type cam lube):
3. Put on head in place, with a 1/4" thick layer of clay over the valve pockets on the piston, with the head gasket, and just lightly snug the head bolts
4. Assemble the rockers on that side for the 2 valves you are testing

Now rotate the engine slowly though 1 full cycle. If it wants to come to a hard stop, don't force it, but I don't think that will happen.

One tricky aspect: Assuming you have hydraulic lifters, then having the springs in place on the head will cause the the lifters to over compress if they are new and have no oil inside of them. The lifter piston will just compress down into the lifter body, and then the valves will not fully open so you have to find away to get some oil in the lifters so the lifter's internal pistons don't just compress down into the lifter body, but not too much oil so that they lock the lifter pistons in the full up position.

Or you take off the valve springs on that test cylinder and put in some light hardware store springs for the test, But if you don't have the tools to take the springs out, you can't do that.
 
For sure use a skim coat of RTV on all flat gasket surfaces; just a thin skim coat. Too much and it can make the gaskets too slick and they will slip out of place. Larger gobs of RTV are needed in the corners of the oil pan, where the pan side gaskets meet the pan end gaskets.
 
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