We have all heard about CMI header issues but
 

How about Crane rockers?
Well my Mercury racing 700's have them
i know they have been around forever and have been used in everything with great results.
Well last year i had one fail at LOTO. mechanic thought it was just a fluke and the rest looked good. well few trips later another one lets go.
so time to pulll them all out and change them. well turns out that there where a few that were failing,
both motors have parts of bearings thru them, not a good thing.

Did a little bit of research and it seems in 2008 Crane went to a different manufacture of the bearings and it can be a hit of miss on them, Just like testing
cmi headers i would advise swapping out the crane rockers. way cheaper than what i'm going thru.

With only 160 hours on them i now get to rebuild both motors :(

Looking forward to this summer with couple brand new motors


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Holy crap!! Are these the standard crane golds that have been in everything for like ever?? lol I have them in mine and I'm now getting nervous! Any pics of the failed rockers and what's going on with them?

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Like these?

What's your plan for replacements?

I had Crane Golds in my Innovation/Volvo 600s with 400 plus high revving hours, and never an issue. Mine were pre 2008 vintage

yep those are what i had, Going with Crowler enduro stainless


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Yikes! Are those shaft rockers you're going with or regular stud mount?

Friend of mine hade a couple of crane gold fail in his 700sci as well, think his boat is 2005

that is the wrong polly nut for those rockers

Good eye. The nut Looks like they are hitting the rocker.

On the Crane Golds, yeh…the old standard ‘good one’s’ had s squarer back , and a few had to be ground to clear some rocker cover bolt hole locations on int valve/ manifold side.

Sorry to hear Dan.. you`ll have no issues with the Crowers.. unless they use the wrong polly nut .

Anyone know the innovation 600 cam specs?

I had the aluminum Jesels that started breaking on me, so a couple grand later I was switched over to steel.

On the CMI issue - inflation is a killer!! Used to be 200 bucks or so to get them welded. My bill last week was $880. Brutal....

Dang. Sorry to hear that. I am running those as well in my 502. Have not had any issues. However, might pick up a set and change them out before boating season gets going just for peace of mind. Would the pushrods have to be changed as well?

I am aware...that was a pic from the first motor shop that screwed me that's been talked about in other threads....that is NOT how my engine is set up now...bought new rockers because of this but still the crane golds....was the only pic I had handy lol thanks for lookin out tho!!

COMP 1620 is a great replacement. ALWAYS check your geometry but we've found they're very close to the golds.
We always replace rockers on a 250hr valve job. I don't know why saving $4-500 is so important to some people on a $50,000 engine.
Valve job from us includes-
Lifters, Rockers, Competition 3 Angle valve job, head milling, ISKY 8205SP Springs, retainers, seals, locks, all fuel filters, plugs, wires, supercharger oil (if applicable), Mercury intake gaskets, cometic head gaskets, water pump impeller, water pump oil, manley valves, if the headers were leaking it likely needs ex valve guides...we do that too, reassembly and dyno testing. What's delivered is as close to a new engine as possible. Any less isn't acceptable. I see people (and marinas....and engines shops...) all the time slap a new set of springs on a 700 and call it a day. That is NOT a valve job. Nor is lapping in the old valves. These are 500-700HP race engines in a very tough environment. They should be maintained as such....they arent a 502 in a Camaro.
Boats are in 4th gear going uphill all day. No coasting, no shifting.

This is what I have done to stabilize my valve train. Crower Pro Magnum rockers, Isky 8205SP springs, ARP studs and a stud girdle.

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Asking because I'm not familiar with either currently....do you get the same result if you run stud girdles vs running shaft rockers? Wondering advantages/disadvantages to either option?

Thanks!

I thought people were moving away from aluminum to steel rockers?

No. Stud girdles a re a great budget way to help stabilize valvetrain. Nothing is a stable as good shaft mount rocker arms. TnD, Jesel, etc.

And not all BBC heads are are the same some aftermarket heads have different valve angles than a GM casting might, so you need to make sure the stud girdle is made for that specific head, I like Webster's..........that sucks for sure Dan


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I am noticing that even when looking at jesel shaft rockers...I have engine quest iron heads that are all ported and such...the spec sheet says "they moved to a 24 degree valve angle" which I'm assuming is what I need to know but can only seem to find them as being product specific like dart or world or brodix etc....need to do some digging/calling to figure it out...

Sorry for the little hijack!! Didn't mean anything by it!

Mine have a lot of shims under the stands, it brings them up really high .
Jesel said it was fine , I don`t like it. Defeats the purpose of a one piece solid stand IMOP , How rigit can it be instead of resting on the head it`s 1.4" high.

All about the geometry. Id take some shims over bad geometry. It's still a LOT stiffer than a stud mounted rocker. Also depends on which jesel rocker you're talking about. The sportsman series isnt nearly as stable as Pro. Jesel also claims Sportsman is "not intended for marine use". We prefer prefer T&D. It's a true full shaft mounted system. It's more money, but they only have one top of the line product. And yeah, we've mad to mill the plates down sometimes and add shims sometimes. There are a million different variables. None of this is truly "bolt on".
If you feel you have "too many" shims either it's the wrong kit for your heads, your pushrod length is off, the valves werent ground correctly, its a 2.300 valve in a 2.250 pocket, blocked is/isnt decked, heads were milled, etc. Something is off.

I went middle of the road , Pro aluminum with solid body . I would have preffered steel but got to draw a line somewhere in the money sand.
A. Solid Body
1.650 Pivot BB Rocker / Weight: 210g
Our strongest rocker body. Intended for use with high cylinder pressure applications such as nitrous and blowers.

To get the geometry right it had to be shimmed, my builder called Jesel and they said it`s all good . maybe I`m exagerating on the heigh . Not like I checked it.

it all depends on the rockers you get i believe

What's the go to rocker for the Mercury Racing 500-700HP now? The old Crane Golds (pre-2008) seemed pretty reliable, I noticed Teague discontinued his line of rockers and selling the COMPs, how does the COMP 1820 compare?

I like the Crower Stainless rockers and I have always had good luck with Harland Sharp aluminum rockers. I have no idea about availibility right now though.

We used COMP 1620 as Gold replacements with great luck.

Well motors are going back in this week,
Even thou it hurt having to listen to Mario at So-Cal Marine in Havasu tell me he wanted to take the motors apart i am sure glad i listened to him now,
i'm guessing that this would not have worked out in my favor in the long run

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Amazing what one part can do to the rest of the motor,

But soon to be reborn


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Dayuum that sux, but looks like you will be good as new and on the water soon!

Check with JOMAR, they make them for a ton of cylinder head companies. They had racks of cylinder heads they used for measuring and checking new designs.

That is exactly what happened to a customer of ours. Bought a 42X from a big Loto boat dealer that claimed they did "valve jobs". All they did was float new springs and throw a set of rocker arms on it. 2 hours after he got it home a lifter took a dump and wiped the cam out. That was right in the middle of covid and the guy damn near lost a whole season while we tried to find a 700 cam.

Pretty sad how some brokers/dealers operate these days. Friend who also bought a 700 powered boat, albeit warmed up 700s, also had failures shortly after when he was told too ends had been redone very recently.

Every time I hear this if I ever buy another I/O I want it to blow up during the sea trail. Then at least I can hammer the price down and know what I have when its finished.

I know that feeling as well. Was buying a new used boat and had it surveyed, but he didn't do engines. The broker wouldn't let me do a compression test so I hired the local mechanic to do it. Paid him $150 and found out later he didn't do the job I paid him for. He lost his compression tester adapter that I found later and never finished the job. The boat only had 50 hours on it and I found out later it had been sitting in a garage and never properly stored. I had so much rust in the bores they had to be honed out to get the rings to seal which required new pistons and of course I made some upgrades during the process. So $12,000 later ...

Second motor is done and getting ready to go back in, just in time for Desert storm and supercat fest west in havasu then off to loto in june

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They look so Pretty


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Beautiful!!

:hitit: