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521 cid broken camshaft dowel for timing gear . bent valves

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Lem Evans
rmcomprandy
lance flake
norm
Dave De
supervel45
maverick172
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Post  supervel45 May 15th 2023, 5:51 am

Lem Evans wrote:Valve clipping the bore what broke the pin??

I would highly suspect that. He said all 8 cylinders at the deck were hit on deck at the exhaust valve area. I mentioned the bent valves as a possible cause but, Murphy's Law would have to be in extreme play to get all 8.

Hey Glen did you notice exhaust valve clearance on your 552 with a 4.42" bore or have any concerns?

You mentioned the 1.70 exhaust valves, and when you halve the bore difference size it is only .015" between the two.

When you start shaving the canted valve heads to reduce chamber volume, the valve angle geometry location to deck contact gets tweaked also.

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Post  maverick172 May 15th 2023, 6:45 am

supervel45 wrote:Maverick did you ever put a caliper on those exhaust valves and verify they are 1.70"?

 
yes they are 1.70 exh

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Post  supervel45 May 15th 2023, 7:08 am

I can't remember from your build but, someone or a couple of people mentioned shaving theirs down to 60 and or 65cc to get more compression? If I am picturing it right in my head, it would seem that would put the valve closer to the deck surface edge?

I would test the clearance with a head gasket installed, and without one, on all 8 cylinders, as close as the valves seem to be on the small bores, with these heads, just for peace of mind, after all this.

Did that Summit calculator help any with the 501 camshaft deal any?

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Post  rmcomprandy May 15th 2023, 10:19 am

Mark Miller wrote:
rmcomprandy wrote:
lance flake wrote:The pin will break when the bolt gets loose or doesn’t have enough clamp force. The pin is only for location. I usually double pin them. This sometimes will keep from getting the cam bad out of time. Seems that it will break a single pin and bend them when doubled.

YEP, the pin(s) are supposed to be for locating the valve timing ... I use a hardened ARP washer with a 7/16-20 rod bolt to get 80 lb/ft of tprque on the bolt; the clamping force is supposed to keep the gear from rotating ... not the pins.
Of course one must be careful that the bolt is not bottoming in the hole.

I have NEVER had a broken pin issue doing it this way ... with over a 1,000 lbs of spring force a lot of times.
.

So you don't use double pins it doesn't sound like you do just making sure?

I don't on my own stuff but, I would do whatever the customer wants for their stuff.

I do keep a drill jig for drilling a hole for a double pin in my go bag whenever I am at a race.

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Post  Lem Evans May 15th 2023, 10:57 am

The exh. valve clip all of the bores?

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Post  maverick172 May 15th 2023, 9:01 pm

Lem Evans wrote:The exh. valve clip all of the bores?
not 100% sure yet going to pull short block out this week and get on stand i have to wait for my vales and gaskets anyways so no sense burning midnight oil yet .. i will post when i find out

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Post  maverick172 May 15th 2023, 9:04 pm

supervel45 wrote:I can't remember from your build but, someone or a couple of people mentioned shaving theirs down to 60 and or 65cc to get more compression? If I am picturing it right in my head, it would seem that would put the valve closer to the deck surface edge?

I would test the clearance with a head gasket installed, and without one, on all 8 cylinders, as close as the valves seem to be on the small bores, with these heads, just for peace of mind, after all this.

Did that Summit calculator help any with the 501 camshaft deal any?

ya it helped calculate some number i think i can make it work i just need to figure out what lash i need to set these valves at now.

ya i decked them .030
so i ordered the valves from kasse today and asked roger in regards to the valves hitting bore on a 4.39 bore and he assured me that they have sold many sets and nobody has had clearance issue and i asked well i cut these .030 and he said they should be fine . i am going to double check while i have the short block apart anyways . i will let you know either way

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Post  Lem Evans May 15th 2023, 9:36 pm

maverick172 wrote:
Lem Evans wrote:The exh. valve clip all of the bores?
not 100% sure yet going to pull short block out this week and get on stand i have to wait for my vales and gaskets anyways so no sense burning midnight oil yet .. i will post when i find out

Did all hit on the side you have the head off of?

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Post  maverick172 May 15th 2023, 10:17 pm

yes sorry i misread your post i have both heads off and all 8 exhaust valves ticked the bore side .1 intake hit on the number 8 piston i guess that valve was fully open when it let loose .i inspected all the other intake valves and they look ok . $20 per valve i am just going to lap them all and replace all i did not think that was to bad of price .
for referance i had the 1028 4.67 bore .041 felpro head gaskets on this time i am going to a 4.5 .040 multi layer steel .
Lem Evans wrote:
maverick172 wrote:
Lem Evans wrote:The exh. valve clip all of the bores?
not 100% sure yet going to pull short block out this week and get on stand i have to wait for my vales and gaskets anyways so no sense burning midnight oil yet .. i will post when i find out

Did all hit on the side you have the head off of?

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Post  maverick172 May 15th 2023, 10:42 pm

supervel45 wrote:I can't remember from your build but, someone or a couple of people mentioned shaving theirs down to 60 and or 65cc to get more compression? If I am picturing it right in my head, it would seem that would put the valve closer to the deck surface edge?

I would test the clearance with a head gasket installed, and without one, on all 8 cylinders, as close as the valves seem to be on the small bores, with these heads, just for peace of mind, after all this.

Did that Summit calculator help any with the 501 camshaft deal any?
i found my camcard for that flat tappet .020 int exh lash setting on it

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Post  supervel45 May 16th 2023, 1:00 am

I saw your pictures and a little more info at the other place. It really seems like you may have had/did two problems, at the same time going, 1. Wrong cam bolt torque 2. Potential valve to block interference  and the extra 700 rpm on that last or last few passes may have come to a head together. If all 8 valves are/were clipping the block, the timing gear/pin was running on borrowed time as Lem and someone else I believe, mentioned.

You have gotten some excellent advice from both places in my opinion.

For the time being I am going to stand by my earlier posts, that you may be a special circumstance, of parts, and tolerance stack, Caused by a bore job/block casting, and head milling, ect., that was off enough, that was too close to the edge, and just did not make the cut. If I am wrong, great and one less problem for you to deal with.

Any way Check and Triple Check everything mentioned, and always be on the lookout for anything you are others may have missed.

PS:1 If the clearance is .010" I would want more personally.

PS:2 You said that engine seemed like turd from the get go. Could the exhaust valves, or some of them, ben "tweaked" a Tad from startup and not sealing good? Just something else to ponder.

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Post  maverick172 May 16th 2023, 6:17 am

you made a very good points . i def will be checking the block clearance for the exh valves
one thing i noticed was 4 of my rocker arms have slight "blueing" on the roller tip which indicate heat . it is ever so slight of colour and off to the one side i am not 100% certain that is was on exh valves these arms as i did not pay attention when i pulled the heads off the other day. you mention the cam bolt incorrect torque and i believe the washer was too small diameter as well.thank you for chiming in on this i def do not want to put back together and have a issue again so i will
replace cam bolt and washer .
check valve to block clearance (how much side clearance shoudl i have)
you said about the valves tweeked from get go you could be correct . i looked at the heads with valves out and seats do not looked burned but they are black but this could of happened after the pin broke and engine came to a halt .i will try get some pictures of the valve seats

supervel45 wrote:I saw your pictures and a little more info at the other place. It really seems like you may have had/did two problems, at the same time going, 1. Wrong cam bolt torque 2. Potential valve to block interference  and the extra 700 rpm on that last or last few passes may have come to a head together. If all 8 valves are/were clipping the block, the timing gear/pin was running on borrowed time as Lem and someone else I believe, mentioned.

You have gotten some excellent advice from both places in my opinion.

For the time being I am going to stand by my earlier posts, that you may be a special circumstance, of parts, and tolerance stack, Caused by a bore job/block casting, and head milling, ect., that was off enough, that was too close to the edge, and just did not make the cut. If I am wrong, great and one less problem for you to deal with.

Any way Check and Triple Check everything mentioned, and always be on the lookout for anything you are others may have missed.

PS:1 If the clearance is .010" I would want more personally.

PS:2 You said that engine seemed like turd from the get go. Could the exhaust valves, or some of them, ben "tweaked" a Tad from startup and not sealing good? Just something else to ponder.

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Post  maverick172 May 16th 2023, 8:31 am

521 cid  broken camshaft dowel for timing gear . bent valves - Page 2 Rock210
521 cid  broken camshaft dowel for timing gear . bent valves - Page 2 Rock110
supervel45 wrote:I saw your pictures and a little more info at the other place. It really seems like you may have had/did two problems, at the same time going, 1. Wrong cam bolt torque 2. Potential valve to block interference  and the extra 700 rpm on that last or last few passes may have come to a head together. If all 8 valves are/were clipping the block, the timing gear/pin was running on borrowed time as Lem and someone else I believe, mentioned.

You have gotten some excellent advice from both places in my opinion.

For the time being I am going to stand by my earlier posts, that you may be a special circumstance, of parts, and tolerance stack, Caused by a bore job/block casting, and head milling, ect., that was off enough, that was too close to the edge, and just did not make the cut. If I am wrong, great and one less problem for you to deal with.

Any way Check and Triple Check everything mentioned, and always be on the lookout for anything you are others may have missed.

PS:1 If the clearance is .010" I would want more personally.

PS:2 You said that engine seemed like turd from the get go. Could the exhaust valves, or some of them, ben "tweaked" a Tad from startup and not sealing good? Just something else to ponder.
here is the worst rocker arm see slight blueing on one side sorry picture little blury but you get idea . you could be correct and the exhaust valve was nicking the block the whole time and created heat possibly ? should i replace these 4 rockers?

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Post  rmcomprandy May 16th 2023, 10:07 am

maverick172 wrote:
supervel45 wrote:I can't remember from your build but, someone or a couple of people mentioned shaving theirs down to 60 and or 65cc to get more compression? If I am picturing it right in my head, it would seem that would put the valve closer to the deck surface edge?

I would test the clearance with a head gasket installed, and without one, on all 8 cylinders, as close as the valves seem to be on the small bores, with these heads, just for peace of mind, after all this.

Did that Summit calculator help any with the 501 camshaft deal any?

ya it helped calculate some number i think i can make it work i just need to figure out what lash i need to set these valves at now.

ya i decked them .030
so i ordered the valves from kasse today and asked roger in regards to the valves hitting bore on a 4.39 bore and he assured me that they have  sold many sets and  nobody has had clearance issue and i asked well i cut these .030 and he said they should be fine . i am going to double check while i have the short block apart anyways . i will let you know either way

If you are going through the entire short block, I think I would be on the safe side and "eyebrow" the top of the bores where there was contact.
The head gasket bore MUST fit correctly to the head, not the bore.

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Post  Lem Evans May 16th 2023, 11:16 am

The valves clipping the block broke the pin. If that's not resolved something will break again. Do the Kaase people know all eight are hitting?

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Post  supervel45 May 16th 2023, 11:43 am

In a perfect world with unlimited funds I would replace the rocker arms.

Did you check the alignment on the valve stems to rocker arm tips?

Did you determine the correct pushrod length?

^Just trying to rule out there was not any other problems that may have been overlooked during the build you may have overlooked, that you can corrected now, is all.

Do the roller tips and center section all turn smooth on the four rockers in question?

I would take Randy's advice on the block.

As far as the clearance, after all this, I would want all I could get that was not going to cause other problems and with the MLS head gaskets, I would think you could get .030" OK.

If it does turn out that it was valve to deck interference, it is a very unique case in the 385 series engine family.

On a side note: I was reading an aviation blog on camshaft/lifter issues, and under aviation rules, in this case, if you have a propeller strike, if you have roller lifters, they are all required to be replaced on inspection. Post #48 Sad

https://www.euroga.org/forums/premature-camshaft-cam-follower-failure/2890?page=1

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Post  Lem Evans May 16th 2023, 1:58 pm

maverick172 wrote:521 cid  broken camshaft dowel for timing gear . bent valves - Page 2 Rock210
521 cid  broken camshaft dowel for timing gear . bent valves - Page 2 Rock110
supervel45 wrote:I saw your pictures and a little more info at the other place. It really seems like you may have had/did two problems, at the same time going, 1. Wrong cam bolt torque 2. Potential valve to block interference  and the extra 700 rpm on that last or last few passes may have come to a head together. If all 8 valves are/were clipping the block, the timing gear/pin was running on borrowed time as Lem and someone else I believe, mentioned.

You have gotten some excellent advice from both places in my opinion.

For the time being I am going to stand by my earlier posts, that you may be a special circumstance, of parts, and tolerance stack, Caused by a bore job/block casting, and head milling, ect., that was off enough, that was too close to the edge, and just did not make the cut. If I am wrong, great and one less problem for you to deal with.

Any way Check and Triple Check everything mentioned, and always be on the lookout for anything you are others may have missed.

PS:1 If the clearance is .010" I would want more personally.

PS:2 You said that engine seemed like turd from the get go. Could the exhaust valves, or some of them, ben "tweaked" a Tad from startup and not sealing good? Just something else to ponder.
here is the worst rocker arm see slight blueing on one side sorry picture little blury but you get idea . you could be correct and the exhaust valve was nicking the block the whole time and created heat possibly ? should i replace these 4 rockers?

Too much heat = not enough oiling.
Any items that have heat color should be replaced.

Lem Evans

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Post  maverick172 May 16th 2023, 7:27 pm

well i have 60 to 70 psi hot oil pressure wot and 15too 25 at idle i could try running thicker oil. my clearnaces are . 032 on mains and .028 on rods if memory serves
Lem Evans wrote:
maverick172 wrote:521 cid  broken camshaft dowel for timing gear . bent valves - Page 2 Rock210
521 cid  broken camshaft dowel for timing gear . bent valves - Page 2 Rock110
supervel45 wrote:I saw your pictures and a little more info at the other place. It really seems like you may have had/did two problems, at the same time going, 1. Wrong cam bolt torque 2. Potential valve to block interference  and the extra 700 rpm on that last or last few passes may have come to a head together. If all 8 valves are/were clipping the block, the timing gear/pin was running on borrowed time as Lem and someone else I believe, mentioned.

You have gotten some excellent advice from both places in my opinion.

For the time being I am going to stand by my earlier posts, that you may be a special circumstance, of parts, and tolerance stack, Caused by a bore job/block casting, and head milling, ect., that was off enough, that was too close to the edge, and just did not make the cut. If I am wrong, great and one less problem for you to deal with.

Any way Check and Triple Check everything mentioned, and always be on the lookout for anything you are others may have missed.

PS:1 If the clearance is .010" I would want more personally.

PS:2 You said that engine seemed like turd from the get go. Could the exhaust valves, or some of them, ben "tweaked" a Tad from startup and not sealing good? Just something else to ponder.
here is the worst rocker arm see slight blueing on one side sorry picture little blury but you get idea . you could be correct and the exhaust valve was nicking the block the whole time and created heat possibly ? should i replace these 4 rockers?

Too much heat = not enough oiling.
Any items that have heat color should be replaced.

maverick172

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Post  supervel45 May 16th 2023, 8:03 pm

Here is a thread on top end oiling. Roller Lifters sometimes need a little help.

https://www.429-460.com/t28104-another-roller-lifter-top-end-oiling-post

Do some more research, as all or different, and it's best to run the oil pump first and see what kind of flow you have, during the build, and then mod them if need be.

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Post  Lem Evans May 16th 2023, 9:42 pm

It's lack of oil to and out of the pushrod.........not at the crankshaft.

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Post  Dave De May 16th 2023, 9:53 pm

maverick172 wrote:well i have 60 to 70 psi hot oil pressure wot and 15too 25 at idle i could try running thicker oil. my clearnaces are . 032 on mains and .028 on rods if memory serves
Lem Evans wrote:
maverick172 wrote:521 cid  broken camshaft dowel for timing gear . bent valves - Page 2 Rock210
521 cid  broken camshaft dowel for timing gear . bent valves - Page 2 Rock110
supervel45 wrote:I saw your pictures and a little more info at the other place. It really seems like you may have had/did two problems, at the same time going, 1. Wrong cam bolt torque 2. Potential valve to block interference  and the extra 700 rpm on that last or last few passes may have come to a head together. If all 8 valves are/were clipping the block, the timing gear/pin was running on borrowed time as Lem and someone else I believe, mentioned.

You have gotten some excellent advice from both places in my opinion.

For the time being I am going to stand by my earlier posts, that you may be a special circumstance, of parts, and tolerance stack, Caused by a bore job/block casting, and head milling, ect., that was off enough, that was too close to the edge, and just did not make the cut. If I am wrong, great and one less problem for you to deal with.

Any way Check and Triple Check everything mentioned, and always be on the lookout for anything you are others may have missed.

PS:1 If the clearance is .010" I would want more personally.

PS:2 You said that engine seemed like turd from the get go. Could the exhaust valves, or some of them, ben "tweaked" a Tad from startup and not sealing good? Just something else to ponder.
here is the worst rocker arm see slight blueing on one side sorry picture little blury but you get idea . you could be correct and the exhaust valve was nicking the block the whole time and created heat possibly ? should i replace these 4 rockers?

Too much heat = not enough oiling.
Any items that have heat color should be replaced.
Your comments about oil pressure and clearances dont have anything to do with Lems comments about the heat stress on those parts. When the valves clipped the block the valve train loads were double or triple normal load. That's why the rockers look over heated which is indicative of over stress. If the intake rockers dont have that blueing appearance its obvious why they are good. If they are blue as well then I'm almost certain that oiling up isn't sufficient. At bare minimum replace all exhaust rockers and roller lifters. I like Randy's idea about clearancing the pistons for valve relief.
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Post  Lem Evans May 16th 2023, 10:12 pm

The load wasn't super high but once......the first time it hit.

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Post  maverick172 May 16th 2023, 11:30 pm

when i talked to roger . he sais " you will not have much clearance on the exh valve but with the small 1.70 valve it will be fine" but i am going to double check once i get my new valves i will mock it up and turn it over he said should try for .120 thou for piston to valve clearance and he said it will only be like .030 clearance on the bore but i am going to see would not take much while i have it apart to do a little eye brow in the top the block on the cylinders..
so the lifter mode to try get more oil to topend i basically score a small "scratch from the pin hole in lifter to the open area in the centre of the lifter . in a way i hope it was the valves nicking the block and the extra rpm is waht caused it to self destuct as it is a easy fix and could of caused the entra stress on my exhaust rocker arms as well. kill 2 birds with 1 stone
Dave De wrote:
maverick172 wrote:well i have 60 to 70 psi hot oil pressure wot and 15too 25 at idle i could try running thicker oil. my clearnaces are . 032 on mains and .028 on rods if memory serves
Lem Evans wrote:
maverick172 wrote:521 cid  broken camshaft dowel for timing gear . bent valves - Page 2 Rock210
521 cid  broken camshaft dowel for timing gear . bent valves - Page 2 Rock110
supervel45 wrote:I saw your pictures and a little more info at the other place. It really seems like you may have had/did two problems, at the same time going, 1. Wrong cam bolt torque 2. Potential valve to block interference  and the extra 700 rpm on that last or last few passes may have come to a head together. If all 8 valves are/were clipping the block, the timing gear/pin was running on borrowed time as Lem and someone else I believe, mentioned.

You have gotten some excellent advice from both places in my opinion.

For the time being I am going to stand by my earlier posts, that you may be a special circumstance, of parts, and tolerance stack, Caused by a bore job/block casting, and head milling, ect., that was off enough, that was too close to the edge, and just did not make the cut. If I am wrong, great and one less problem for you to deal with.

Any way Check and Triple Check everything mentioned, and always be on the lookout for anything you are others may have missed.

PS:1 If the clearance is .010" I would want more personally.

PS:2 You said that engine seemed like turd from the get go. Could the exhaust valves, or some of them, ben "tweaked" a Tad from startup and not sealing good? Just something else to ponder.
here is the worst rocker arm see slight blueing on one side sorry picture little blury but you get idea . you could be correct and the exhaust valve was nicking the block the whole time and created heat possibly ? should i replace these 4 rockers?

Too much heat = not enough oiling.
Any items that have heat color should be replaced.
Your comments about oil pressure and clearances dont have anything to do with Lems comments about the heat stress on those parts. When the valves clipped the block the valve train loads were double or triple normal load. That's why the rockers look over heated which is indicative of over stress. If the intake rockers dont have that blueing appearance its obvious why they are good. If they are blue as well then I'm almost certain that oiling up isn't sufficient. At bare minimum replace all exhaust rockers and roller lifters. I like Randy's idea about clearancing the pistons for valve relief.

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Post  maverick172 May 16th 2023, 11:31 pm

thank you for posting this i read it seems pretty straight forward make a scratch from hole in lfter to the open centre part of lifter ..
supervel45 wrote:Here is a thread on top end oiling. Roller Lifters sometimes need a little help.

https://www.429-460.com/t28104-another-roller-lifter-top-end-oiling-post

Do some more research, as all or different, and it's best to run the oil pump first and see what kind of flow you have, during the build, and then mod them if need be.

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Post  Lem Evans May 17th 2023, 7:56 am

What lifters do you have?

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