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Discussion Starter #1
I got the boat back on the water today. Got the timing set and it was running freakin' awesome...


But then I noticed it was running really hot, so I figure, maybe it needs to be driven. So I get her out. She was slower out of the hole then it should be, and then it as only turning 5000 RPM (A/B impeller, 496 BBC roller cam, OT headers, big valve head 10.5:1 CR, tunnel ram, dual holley 600's VS). Now, this is going to be very hard to describe, but I"ll try

Then, I started hearing this awful noise, it sounded like a metal on metal tap, (almost like a loose rocker or something) but it was a hollow tap, and was coming from the top, like by the carbs; it was also sporadic, but still increased with throttle. The water was like 215 F, we had to idle back into the ramp. And there is water in the oil now, not a ton, but its milky.

So I'll tell you what I deduce before even tearing into anything. I think its intake gaskets, and that popping noise is the hot boiling water coming up through the intake manifold...and the gaskets being the cause of it running so hot.

What say you?!

Thanks!!
 

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Discussion Starter #2
I'm gonna pull the valve covers off just to verify it wasn't a rocker (i'm pretty sure its not) and I'm also going to try to do a compression test.
 

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Start tearing it down until you find the problem. any idea why it got hot? You`re really going to see a mess under the valve covers. getting hot, water in the oil and then a knock. hate to sound like the grim reaper but i think you`re about to experience buying some new parts and a total rebuild. i hope i`m wrong and i wish you good luck. post what you find.
 

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Broken rocker or stud on exhaust, excess cylinder pressure poped head gasket at water jacket, Just a guess :happy: hope it's nothing real nasty.
 

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Discussion Starter #6
well, I took the valve covers off, the rocker to the exhaust valve on #8 was barely hanging on. I also found some other loose rockers.

So I'm assuming that cylinder pressure blew the head gasket. But nothing looked broken, and the pushrod wasn't even bent, so I think it shouldn't be that big of a deal to fix...Kinda excited it ran that good with loose rockers and a blown head gasket :))THumbsUp

anyone know the rocker arm tightening specs?
 

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You might try setting the lifters and runninig a compression test. It's possible that is all that is wrong with it. They will put water in the oil someitmes when an exhaust rocker is off.
Duane HTP
 

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What type of lifters? If hydraulic, then I go 1/4 turn past 0 lash. I would recommend replacing all the rocker nuts with new ones. It is fairly common if they have been re-used more than once that this can happen. And I agree about the water could have come from this. Seen it first hand. Doesn't explain why it got hot though...curious about that one. Good luck with it, hope it works out easily.
 

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Discussion Starter #9
Thanks for the tips guys.

I'll look into rocker nuts, they are hydraulic lifters. Can I order those from Jegs or something? They are Crane Gold Roller Rockers.

Thanks!
 

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Discussion Starter #10
so to verify

I should go to top dead center, compression stroke, on each cylinder, and tighten the lifters until I can't freely spin the pushrod through my fingers anymore, then another 1/4 turn?
 

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Thanks for the tips guys.

I'll look into rocker nuts, they are hydraulic lifters. Can I order those from Jegs or something? They are Crane Gold Roller Rockers.

Thanks!
Do you have stud girdles? This is a good time to buy some if you don't! Peace of mind and you get polylock nuts for the rockers!
Setting hydraulic lifters is not hard! There is a simple way I will see if I can find the info. and post it for ya! That way you don't get confused with my wording!:shock:

Here ya go! http://www.centuryperformance.com/adjusting-valve-lash-spg-149.html
 

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Check-

Check to see what the lifter manufacturer says about the lifters and preload adjustment. Comp Cams has some "minimum preload" hydraulic lifters that take less than 1/16 turn past zero lash to correctly set the preload- you can try and set them by the "1/4 - 1/2" turn method and screw some stuff up- like I did. :)bit
 

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Discussion Starter #13
I'm wondering if they were set wrong before....

Turns out the poly lock was broken on the #8 ex valve. As I was going to set lash, I started to tighten down some that were loose, and SNAP! Two more were cracked, and are now broken. What would cause this?
 

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Discussion Starter #15 (Edited)
I can snap some pics. I'm thinking they weren't tight enough, and the rocker was moving around and cracked it all the way around.... and they are in 2 pieces


I'm worried about the others though...should I just get a brand new set of poly locks and replace them all??
 

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Discussion Starter #16
sooo...

I got new poly locks, and I spent awhile adjusting the rockers and I really think they are perfect but...

When I go to start it, its acting like its only hitting on a couple cylinders and won't start. I don't know if i adjusted the rockers a bit too tight or what. I guess I'm just looking for suggestions as to what I could have forgotten or am not doing right?? I'll tell you how I adjusted the rockers.

I've seen about 650 ways to adjust the rockers, so, a highly regarded, all things engine, expert I know told me his best way to do it, was to adjust the intake at exhaust slightly open, and exhaust at intake 2/3 closed (to ensure base circle on cam). I started by cranking the engine for about 20 seconds to ensure there was oil pressure and the lifters were pumped up. and I began on the starboard bank, and did this roughly, I would turn it over by wrench, and check them all, and if one was a little loose, I tightened it about a quarter turn. cranked the engine over for about 20 seconds and checked again.

I did this on the other side, cranked, when one was loose I only tightened about a quarter turn.

Could I possibly have screwed that up? I need to be on the water today and I gotta figure this out!

Thanks guys!
 

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sooo...

I got new poly locks, and I spent awhile adjusting the rockers and I really think they are perfect but...

When I go to start it, its acting like its only hitting on a couple cylinders and won't start. I don't know if i adjusted the rockers a bit too tight or what. I guess I'm just looking for suggestions as to what I could have forgotten or am not doing right?? I'll tell you how I adjusted the rockers.

I've seen about 650 ways to adjust the rockers, so, a highly regarded, all things engine, expert I know told me his best way to do it, was to adjust the intake at exhaust slightly open, and exhaust at intake 2/3 closed (to ensure base circle on cam). I started by cranking the engine for about 20 seconds to ensure there was oil pressure and the lifters were pumped up. and I began on the starboard bank, and did this roughly, I would turn it over by wrench, and check them all, and if one was a little loose, I tightened it about a quarter turn. cranked the engine over for about 20 seconds and checked again.

I did this on the other side, cranked, when one was loose I only tightened about a quarter turn.

Could I possibly have screwed that up? I need to be on the water today and I gotta figure this out!

Thanks guys!
Do one cylinder at a time, loosen both rockers , turn the balancer clockwise till the exhaust rocker just starts to move, set the intake, tighten it while turning the pushrod with your fingers just till you feel the slightest amount of resistance, this is zero lash , now go a 1/4 turn more. Next continue to turn the balancer clockwise till the intake opens all the way then just begins to close, now set the exhaust rocker, same way roll the pushrod as you tighten the rocker till the slightest amount of resistance is felt then preload another 1/4 turn. Do all the other cylinders this way and your done.
This is for a hydraulic cam only, from your post I understand thats what you have, a solid sets the same except you use a feeler guage and leave clearance instead of adding preload.
Good luck, Hass

ps. dont forget to look those poly locks over real good and make sure that they dont have any interference problems with your rockers. Some are different diameters, some have a machined step in the end that registers into the rocker fulcrom, different lengths, ect.
 

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Then, I started hearing this awful noise, it sounded like a metal on metal tap, (almost like a loose rocker or something) but it was a hollow tap, and was coming from the top, like by the carbs; it was also sporadic, but still increased with throttle.

Thanks!!
Did You ever figure out what the hollow metal sound was?...Hal
 

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Discussion Starter #19
Thanks guys.

yeah, I went through and loosened them all up and it started right up, and accepts throttle, no noises. So I think that's all it was and its good now...i hope.

Did You ever figure out what the hollow metal sound was?...Hal
yeah, it was the push rod either hitting the way too loose rocker because the poly lock broke, or it was coming up and hitting the valve cover...that issue is resolved.
 

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Not trying to hi-jack ur thread, but I too have a similar issue!!! Made a couple of passes, tubbed the kids, n cruised at 3k...chillrd for awhile n had a noisy valve train, mostly when jet is water...But I wasn't running hot!!!! Full solid roller cam girdled!!! BBC 461...single plane intake...781 heads with ss valves n bigger intake valves!!! Broken poly lock? Broken spring? Btw comp cam 742, 749 lift, Harlan sharp roller rockers n Webster girdle.
 
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