Help me find the umph in my 360

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Did you do all cylinders? I would.
I was after I posted that. and I have one valve number 7 intake valve stuck up. It never hit the piston. So I think it was a issue that had already occurred. Like a bad valve guide on the valve. I tried tapping the valve slightly with a hammer. And it won't pop back up.

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I was after I posted that. and I have one valve number 7 intake valve stuck up. It never hit the piston. So I think it was a issue that had already occurred. Like a bad valve guide on the valve. I tried tapping the valve slightly with a hammer. And it won't pop back up.

View attachment 1716115283

View attachment 1716115284
....but nice diagnostic work! It's probably bent from tapping the piston.
 
I think that's the correct decision.....and if it was MINE, they'd both be coming off. Just some friendly advice
I'm going to pull both. But I did go ahead and do a form for summit racing on these heads about this stuck valve. They were bought on April 14th of this year. When I take the heads off I will inspect to see if even that valve even got stuck or it actually got hit. Either way, they will either be returned or I will have to get all new guides and maybe a valve. Because now I don't trust them on the heads.
 
I'm going to pull both. But I did go ahead and do a form for summit racing on these heads about this stuck valve. They were bought on April 14th of this year. When I take the heads off I will inspect to see if even that valve even got stuck or it actually got hit. Either way, they will either be returned or I will have to get all new guides and maybe a valve. Because now I don't trust them on the heads.
I understand. Good luck and keep us posted. Good job on finding it!
 
I understand. Good luck and keep us posted. Good job on finding it!
Either way I'm just going to pull the engine back out. These headers already have such a hard time getting enough space to move there would be no way for me to get to the bottom studs. So engine pulling time.
 
Either way I'm just going to pull the engine back out. These headers already have such a hard time getting enough space to move there would be no way for me to get to the bottom studs. So engine pulling time.
Probably a smart move. I'd come over and help if we were local.....not that it's worth anything. lol
 
Replace the valve springs on one cylinder with light "checking" springs. You can get these at most any hardware store. Just hold the valves closed but not enough to collapse the lifters. Then use a dial indicator on the retainer and hand turn the engine to/through 20° BTDC to TDC and then on the other valve from TDC to 20° ATDC. This will tell what valve clearance you have now with you lift. The way to measure is every 5°, open the valve by operating the rocker arm until the retainer touches the stem seal or the valve touches the piston. This will inform how much valve to piston clearance you have and at what ° closest approach is. Depending on your pistons, 0.508" lift these days is not excessive. Older engines only used 0.350" to 0.400" as the spring technology was not as developed. Now you can run 0.600" on the street reliably, provided you double check all clearances and use recommended springs.
How old are You??? No, We didn't have conical/behives until the OE's started using them in the '80's & '90's, but We ran mid-.500"'s to .600" with duals w & w/o dampers just fine on the street. What are You talking about?? 340's shifting in the mid-7K's, ****, the Olds 455 I built is running 6,500 with a .570" lift Comp Xtreme Energy Hyd. cam. It's been running since '07 that way.
You're talking to a Member that might have 7.5:1 squeeze & is rightly looking to change cams/cam timing, & You've got the advice of basically starting from scratch & building an entirely new & $$$$ mill ?!?!?!
I appreciate posting informative stuff, & respect the guidance that folks like DV has to offer, but this isn't the moment for that stuff.
The OP just wants to get the best grunt from THIS mill, I'm sure when He's got the trans etc. He wants in & sorted, He might be ready to build a Trickflow headed stroker with all the "right" things done to it........
 
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How old are You??? No, We didn't have conical/behives until the OE's started using them in the '80's & '90's, but We ran mid-.500"'s to .600" with duals w & w/o dampers just fine on the street. What are You talking about?? 340's shifting in the mid-7K's, ****, the Olds 455 I built is running 6,500 with a .570" lift Comp Xtreme Energy Hyd. cam. It's been running since '07 that way.
You're talking to a Member that might have 7.5:1 squeeze & is rightly looking to change cams/cam timing, & You've got the advice of basically starting from scratch & building an entirely new & $$$$ mill ?!?!?!
I appreciate posting informative stuff, & respect the guidance that folks like DV has to offer, but this isn't the moment for that stuff.
The OP just wants to get the best grunt from THIS mill, I'm sure when He's got the trans etc. He wants in & sorted, He might be ready to build a Trickflow headed stroker with all the "right" things done to it........
Well kinda have to pull the engine now lol
 
I had less than 50 miles on my then new Indy LAX heads (67 Barracuda 360) when all of a sudden had a horrible knocking noise. Got a little quieter, and I was less than five miles from home, so I just drove it home. Pulled the valve covers, saw that the intake valve in the #7 cylinder was stuck open, so I removed that head, expecting the worst. Barely a scratch on the piston, and the valve seat was OK, but the valve looked like this:

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Took a chance and only removed the one head. Got a new valve from Indy, machine shop lightly honed the guide to proper clearance, I put it back together and it's been running fine since. And this was almost a dozen years ago. So maybe there's hope for you. :thumbsup:
 
I had less than 50 miles on my then new Indy LAX heads (67 Barracuda 360) when all of a sudden had a horrible knocking noise. Got a little quieter, and I was less than five miles from home, so I just drove it home. Pulled the valve covers, saw that the intake valve in the #7 cylinder was stuck open, so I removed that head, expecting the worst. Barely a scratch on the piston, and the valve seat was OK, but the valve looked like this:

View attachment 1716115547

Took a chance and only removed the one head. Got a new valve from Indy, machine shop lightly honed the guide to proper clearance, I put it back together and it's been running fine since. And this was almost a dozen years ago. So maybe there's hope for you. :thumbsup:
Another LAX valve issue, when My Bud pulled the 340 out of His AAR, He stuck a 408 stroker with those heads back under the 6bbl setup(which was already running mid/lower 12's). Valve came down & bent, luckily didn't break anything, locks sheared...they sent Him new locks & a valve stating they suspected the hardening of those locks. Been running OK since.
 
K
Yeah I'm not going to push this engine past 5300

How old are You??? No, We didn't have conical/behives until the OE's started using them in the '80's & '90's, but We ran mid-.500"'s to .600" with duals w & w/o dampers just fine on the street. What are You talking about?? 340's shifting in the mid-7K's, ****, the Olds 455 I built is running 6,500 with a .570" lift Comp Xtreme Energy Hyd. cam. It's been running since '07 that way.
You're talking to a Member that might have 7.5:1 squeeze & is rightly looking to change cams/cam timing, & You've got the advice of basically starting from scratch & building an entirely new & $$$$ mill ?!?!?!
I appreciate posting informative stuff, & respect the guidance that folks like DV has to offer, but this isn't the moment for that stuff.
The OP just wants to get the best grunt from THIS mill, I'm sure when He's got the trans etc. He wants in & sorted, He might be ready to build a Trickflow headed stroker with all the "right" things done to it........
How old are You??? No, We didn't have conical/behives until the OE's started using them in the '80's & '90's, but We ran mid-.500"'s to .600" with duals w & w/o dampers just fine on the street. What are You talking about?? 340's shifting in the mid-7K's, ****, the Olds 455 I built is running 6,500 with a .570" lift Comp Xtreme Energy Hyd. cam. It's been running since '07 that way.
You're talking to a Member that might have 7.5:1 squeeze & is rightly looking to change cams/cam timing, & You've got the advice of basically starting from scratch & building an entirely new & $$$$ mill ?!?!?!
I appreciate posting informative stuff, & respect the guidance that folks like DV has to offer, but this isn't the moment for that stuff.
The OP just wants to get the best grunt from THIS mill, I'm sure when He's got the trans etc. He wants in & sorted, He might be ready to build a Trickflow headed stroker with all the "right" things done to it........
With low compression you do not want a long cam with a bunch of overlap bleeding off what you do have. My INTENT was offering how to check valve to piston clearance to verify if a shorter duration higher lift cam can be installed. This could build more cylinder pressure at lower RPM to get some snap in the engine.
How old am I? Well probably as old or older than you. Been around cars all my life and learned a few things over the years. And smartass posts that do not try to offer assistance do no good.
 
K




With low compression you do not want a long cam with a bunch of overlap bleeding off what you do have. My INTENT was offering how to check valve to piston clearance to verify if a shorter duration higher lift cam can be installed. This could build more cylinder pressure at lower RPM to get some snap in the engine.
How old am I? Well probably as old or older than you. Been around cars all my life and learned a few things over the years. And smartass posts that do not try to offer assistance do no good.
Overlap does not "bleed off" compression.
Telling somebody they "oughta have zero-deck for SQUISH" when they just built the engine with stock low squeeze slugs, isn't assistance, so there's that.
Telling the OP that a lot of the small bump in squeeze of the heads got taken away in the thermal conductivity of the Al-U-minimum they're made out of is helpful.
Throwing a basket of coulda/woulda/shoulda's is not.
Telling someone cams were limited to .300-.400" lift because valve springs weren't up to any more is ridiculous, and also not helpful. Guess My stock Slanty with .412" design lift was really living on the edge with it's lame-*** weaker than a stock 'teener valve springs...wheeee!!!!
The OP asked for, & was given good council on the camshaft, advance the one He has or get a smaller one. There are obviously other issues going on with the mill at the moment.
No need to be angry, but You're simply giving bucketloads of info that don't apply to Him, swirls/fast-burns/squishes etc. Great info if He starts over again, and I appreciate the desire to educate, but the valve spring thing....well....
 
With low compression you do not want a long cam with a bunch of overlap bleeding off what you do have.
Bingo. You need to actually compress the mixture to help further gasify it so you can burn it as liquids don't burn in ICE's only the fraction that has been converted to a gas. If you can't do it on the compression stroke (help vaporize it) then you need to get it done as it leaves the carb, in the intake manifold and at the valve curtain area. Add to that the fact that modern street fuel has a much higher distillation temp then they require even more heat imputation to the fuel to convert it to a usable gas state.

There's a reason cam companies offer compression ratio guidelines for their respective camshafts.
 
Bingo. You need to actually compress the mixture to help further gasify it so you can burn it as liquids don't burn in ICE's only the fraction that has been converted to a gas. If you can't do it on the compression stroke (help vaporize it) then you need to get it done as it leaves the carb, in the intake manifold and at the valve curtain area. Add to that the fact that modern street fuel has a much higher distillation temp then they require even more heat imputation to the fuel to convert it to a usable gas state.

There's a reason cam companies offer compression ratio guidelines for their respective camshafts.
The howards camshaft I got is going to be a a better camshaft for my engine. Yes there are more problems now that I found like the number 7 intake valve dropped because of a bad valve guide. Luckily summit said these heads are under warranty for a year and I bought them in April of this year. So when I get the replacement heads I'm going to get them inspected by arperformance that's near me. One of the best shops in Arkansas. Would it be worth getting them milled to raise compression?
 
If the camshaft requires it then yes.
That is one solution. The 0.110" deck height is a concern to me. Are your pistons press fit pins or full floating? You could also probably get 0.050" milled off the block decks which would also help. Yes, I know that requires pulling the engine apart. At this point with new heads and cam, the cam can be degree'd and valve to piston clearance verified. You might get away with a very light hone in the cylinders and reuse the rings.
If the pistins are floating pin design, you might be able to find pistons with a larger CD, like +0.100" to raise static compression without milling the block or/and heads. Remember that over "X" amount milled off the heads and/or block on a V engine requires milling the intake manifold to align correctly. The machine shop will know what is required.
 
Ok. So great news! Summit is sending me a new set of heads and .039 thickness gaskets under warranty.
 
Ok. So great news! Summit is sending me a new set of heads and .039 thickness gaskets under warranty.
Good to hear that.
What is the specs on the Howard's cam you are getting. All this to build an engine is getting so costly these days. For Canada we add about 35% for $ exchange rate and probably going to get worse with the Left Dishonourable Prime Peckerhead of Canada, daesh Dustbin Turdo and his merry band of embezzelers.
How is AZ this year. We had a very dry spring and then forest fires, some were arson. This was followed by heavy rain one weekend that caused flooding. This has been followed by swarms of mosquitos I have not experienced in decades. Now the last 3 days have had pretty good thunderstorms in the evening with monsoon like downpours. Welcome to Canada, eh.
 
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