MTS VT59 Shaft Rocker System with ARP Studs Clearance Issue

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MTS VT59 Shaft Rocker System with ARP Studs Clearance Issue

Postby BigDaddyT » Sun Mar 12, 2017 6:07 pm

Has anyone else had to shim the crap out of their shaft rocker system due to using ARP studs which appear to be about an 1/8" too tall on Cadillac heads? I checked with MTS before ordering the studs to ensure that there was enough clearance and they assured me they use them all the time. I have chased the threads to ensure that there is no leftover crap in the bottom of the hole so I don't think it is that. I do not want to resort to cutting the studs but shimming that height will change the geometry somewhat. Anyone have any ideas? Appreciate any help. Tom
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Re: MTS VT59 Shaft Rocker System with ARP Studs Clearance Issue

Postby Deano » Sun Mar 12, 2017 6:27 pm

That sounds like something is abnormal. I wouldn't want to shim them that far.
Not only is that probably not preferable, but could be an issue if
you already have pushrods and will only complicate VC clearance.

Almost sounds like the wrong studs, but that seems more than unlikely from MTS.
Did the machine shop supply them or did you by chance get them elsewhere? What part # are they?
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Re: MTS VT59 Shaft Rocker System with ARP Studs Clearance Issue

Postby BigDaddyT » Sun Mar 12, 2017 6:43 pm

Hey Deano. The studs were purchased from Summit Racing and the Shaft Rocker System was the VT59 from MTS. Here is the link to the studs from Summit. https://www.summitracing.com/parts/arp- ... plications. I have not torqued down the heads yet but the instructions state to tighten them only hand tight then torque them down. I can't believe that they would tighten down an 1/8" .
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Re: MTS VT59 Shaft Rocker System with ARP Studs Clearance Issue

Postby One Eyed Gator » Mon Mar 13, 2017 1:34 pm

Deano sounds, more like the norm when it comes to performance caddy stuff. Always some kind of issue. Every part I bought seem to need some kind of modification to work correctly.

That I why I moved on to the LS platform. Love a Caddy but will never go back.

Can Almost buy a junkyard 6.0 for what the that rocker set-up cost.

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Re: MTS VT59 Shaft Rocker System with ARP Studs Clearance Issue

Postby SWAMPHUNTER45 » Tue Mar 14, 2017 4:18 pm

None of the high performance upgrades are simple or easy.

Per Mr Branch:
In regard to the studs, some early production blocks are drilled shallow.
Some mid generation blocks are not fully threaded and you end up a few threads short.
The late model striation block usually is not an issue....Deano :stirpot:

Next struggle may very well be that your push rods will not clear. It is not uncommon to be forced to open up the passages depending on the rockers geometry. I have used FE MAX and seen a MTS install both needed additional clearance even when using the smaller diameter thick wall push rod. The only shaft rocker set to date that was a direct bolt on without needing clearance modification was the T&D system used on my original 514 now on Blu's boat. Without a doubt T&D has there design in proper specification for the 472 / 500 platform.


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Re: MTS VT59 Shaft Rocker System with ARP Studs Clearance Issue

Postby Deano » Tue Mar 14, 2017 5:39 pm

No questioning that makes sense, it wasn't something that occurred to me.
I've used Harland Sharp, RAS, and some early MTS shaft systems and not had that issue.
It wasn't something that I ever thought about before,
but guess I never put studs in, AND shaft rockers on, an early block. :scratch:

I have a later block on a stand, so went and measured those holes. They vary a little bit, but are all between 1.181 and 1.121. Tom, see what yours measure and that should confirm that possibility one way or the other. I'll be home tonight, give me a call whenever you get that far.

Evidently, STRIATIONS have their rewards. :lol:
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Re: MTS VT59 Shaft Rocker System with ARP Studs Clearance Issue

Postby BigDaddyT » Wed Mar 15, 2017 8:47 am

Thank you for all the responses. Sorry that I haven't replied yet as the mother-in-law is in the hospital so that takes precedence. I will pull the heads off in the next day or so and measure the depth of the holes. It appears that there are 3-4 stud threads above the deck of the hole so what Eric and Deano said makes sense. I believe I have a 1970 block and heads as they are small chamber 76cc but cannot be sure, of course, as the heads could have been pulled from another block at some point. I reached out to Paul at MTS and he stated that "he had never run into this but has reached out to two other builders to see if they have seen this issue before." I know ARP only lists one part number for their studs so it's not like I have any choice over lengths. Deano, I will give you a call later this evening if you are available. After I measure the holes, I'll post my results. Thanks again for the responses.
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Re: MTS VT59 Shaft Rocker System with ARP Studs Clearance Issue

Postby BigDaddyT » Wed Mar 15, 2017 11:33 am

Reply from Paul at MTS:

"Hi Tom, while I have never run across the issue, I found someone who has heard about the ARP Studs issue happening a handful of times in his 30 years of Cadillac engines.

"On rare occasions the holes in the the block are not tapped or were tapped short. If the studs sit too high he will need to either:

(A) clearance the rocker stands - or
(B) Shim the stand up....Not a great idea
(C) Or he could source 10 shorter studs

I think the miliron studs clear....."

-Paul"

So looks like I have to come up with plan B:. Might just be best to buy a new bolt set from MTS and move on.

Thanks again for everyone's responses. I could never gotten this far without the help of the Caddy folks like Deano and Eric on this board.
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Re: MTS VT59 Shaft Rocker System with ARP Studs Clearance Issue

Postby Waterthunder » Fri Mar 17, 2017 12:59 pm

This is what happens everyday with everything. If you expect aftermarket performance parts to fit. You will change that idea after a little but of experience.
THE PROOF IS IN THE PROP!

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Re: RE: Re: MTS VT59 Shaft Rocker System with ARP Studs Clearance Issue

Postby BigDaddyT » Sat Mar 18, 2017 3:02 pm

Waterthunder wrote:This is what happens everyday with everything. If you expect aftermarket performance parts to fit. You will change that idea after a little but of experience.

WaterThunder,
I am quickly learning that with this build. You end up with a lot of money in it and lots of plan b's.


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Re: MTS VT59 Shaft Rocker System with ARP Studs Clearance Issue

Postby BigDaddyT » Sat Mar 18, 2017 9:44 pm

Well I did some measuring today and here is what I found. The hole depth as measured from the bottom of the hole to the deck is 1,260". The stud threads measure this same amount. Therefore, I'm guessing that the holes are not threaded completely to the bottom of the hole. I also compared the existing bolt threads with the new studs and the new studs are about 3 threads longer in length. I tried looking down the holes but at 61, my eyesight leaves a lot to be desired. So I am left with what appear to be two choices, a new bolt set from Cadco or MTS or try the Milodon stud set as Paul thinks that it fits. I have attached photos for everyone to see. Hopefully this will help someone else out.

Image

Image

Image
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Re: MTS VT59 Shaft Rocker System with ARP Studs Clearance Issue

Postby SWAMPHUNTER45 » Sun Mar 19, 2017 6:58 am

I would use head bolts in a 8.5 ratio build and make life easy.

Just be looking for the next possible problem of push rod contact and is there any clearance issue to the bolt heads by the rocker shaft base. I highly doubt any issue with the base but at least be looking ahead. The push rods can not touch the block passage at all or you will have a bind and failure so once at that stage of assembly check every single one thru their full range of motion. Again, I doubt it will be an issue but should this go undetected it would be a serious fail.

It also appears that the stud shown is galled and if reused the treads will need to be chased telling me it is not tapped to the bottom. This is common, Mr. Branch said usually 4 threads short and that is exactly what that stud is revealing in your photo. I feel your block is probably a 71-74 what we refer to as a mid generation.

Rumor on the street is Deano is hogging up all the late model striation blocks! :stirpot:

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Re: MTS VT59 Shaft Rocker System with ARP Studs Clearance Issue

Postby Deano » Sun Mar 19, 2017 9:59 am

Well, a couple of random thoughts/comments will not change what you've already determined, but if you wanted another mildly informed opinion that may be of little more than no value, I can help you out. :lol:

First, you are to be commended for your photography skills, as all three pictures tell the same story. The last one in particular represents a textbook quality picture of the scenario you find yourself with. It would take me ten attempts to arrive at that end, if I ever was able to. Getting the flash to the bottom of that hole and focused is a pretty damn good trick. :thumbleft:

Anyway, if I were in your position I would not hesitate to use bolts and call it good. There is no reason that I am aware of that doing so would create any issues. For the benefit of whoever may read this and is wondering why not just finish tapping the holes and use the studs, the answer is that these blocks have a high nickel content and as such are very hard. While this is a good thing in most instances, it greatly increases the odds of breaking off a tap in the hole. It would suck pretty hard to have that happen with a newly machined block.

As Swamphunter points out, pushrod clearance needs to be checked in any case. I've not used those specific shaft rockers, but it seems to me like the ratio being 1.7 is about the push point. If the ratio is <1.7, it's generally not an issue at all. If the ratio is =>1.72 or you have fat pushrods, the holes will need to be opened up. I believe (but may be wrong) that those are a 1.7 ratio so I would hope and expect they would be OK with standard pushrods, which would suffice for your build, IMO. If you have bigger pushrods, I would half way expect the holes to need tweaking, which isn't so bad as long as it's before you get to the intake.

To my knowledge the water outlet for the heater was moved from the block by the WP to the back of the head in 72. Additionally, the '74 472s were the only year with flat top pistons that yours lacked, so it's earlier than that. The 71-73 472s were low compression, so given your block, and the pistons that came out of it, must be a 71 or maybe 72. Not that it gets you anything beyond half tapped head bolt holes. :violent1:

In any case, I concur with Swamphunter and would get some bolts and go . . .


@ Swamphunter - I ain't hoarding nothin'. I only have three that aren't already on a boat, and one of them doesn't really count. It came out from under a collapsed hay loft and was breading mosquitoes for a few years before I bought it for the crank. :lol: If I live long enough to get that far, I will post some pics. It will have been quite the clean up if I am ultimately able to use it.
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Re: MTS VT59 Shaft Rocker System with ARP Studs Clearance Issue

Postby BigDaddyT » Sun Mar 19, 2017 11:31 am

Thanks Erik and Deano for your replies. I truely value reasoned responses that help point me in the right direction and point out things that I might not have thought about. I has taken me over a year and a half to get to this point so I don't want to screw something up and have to redo it.

Deano, I do have the heater outlet at the base on my radiator hose outlet so my guess is that it is, as you say, early 70's.

Erik, could you please elaborate on your "I would use head bolts in a 8.5 ratio build and make life easy" response as I don't fully understand what you were telling me. As for the stud being galled, that is simply ARP installation grease that was not wiped off. It looks deceiving in the photo.

I guess I will source some grade 9 bolts and call it a day.

Thanks again for the responses. Tom
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Re: MTS VT59 Shaft Rocker System with ARP Studs Clearance Issue

Postby Deano » Sun Mar 19, 2017 11:56 am

I believe all that he was saying is that given that your rebuild is using the lower compression ratio, that head bolts will be sufficient. And that while studs may have been preferable, they are not mandatorily necessary for that level build.

I kind of suspected that was grease on that stud . . . I will admit though, I debated with myself about commenting on the strength you must have in your fingers to be able to twist those threads like that. :shock: You wouldn't be someone I'd want to arm wrestle for money ! :lol:
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Re: MTS VT59 Shaft Rocker System with ARP Studs Clearance Issue

Postby SWAMPHUNTER45 » Sun Mar 19, 2017 1:19 pm

Yes

No real need to stud an 8.5:1 in my opinion that was what I was trying to relay.

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Re: MTS VT59 Shaft Rocker System with ARP Studs Clearance Issue

Postby Scarecrow » Sun Mar 19, 2017 1:49 pm

Why not cut or grind those to the right length?

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Re: RE: Re: MTS VT59 Shaft Rocker System with ARP Studs Clearance Issue

Postby BigDaddyT » Sun Mar 19, 2017 2:09 pm

SWAMPHUNTER45 wrote:Yes

No real need to stud an 8.5:1 in my opinion that was what I was trying to relay.

Thanks for the clarification Erik.

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Re: RE: Re: MTS VT59 Shaft Rocker System with ARP Studs Clearance Issue

Postby BigDaddyT » Sun Mar 19, 2017 2:11 pm

Scarecrow wrote:Why not cut or grind those to the right length?

Thought about that Scarecrow but read that Grade 9 studs would be hard to cut and rethread if necessary with ordinary tools.

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Re: RE: Re: MTS VT59 Shaft Rocker System with ARP Studs Clearance Issue

Postby BigDaddyT » Sun Mar 19, 2017 2:31 pm

Deano wrote:I believe all that he was saying is that given that your rebuild is using the lower compression ratio, that head bolts will be sufficient. And that while studs may have been preferable, they are not mandatorily necessary for that level build.

I kind of suspected that was grease on that stud . . . I will admit though, I debated with myself about commenting on the strength you must have in your fingers to be able to twist those threads like that. :shock: You wouldn't be someone I'd want to arm wrestle for money !

Makes perfect sense now Deano. I wasn't thinking C/R.

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Re: MTS VT59 Shaft Rocker System with ARP Studs Clearance Issue

Postby BigDaddyT » Sun Mar 19, 2017 6:49 pm

Which of these bolts would be more acceptable? I'm not sure if zinc plating is ok in an engine even though they come in Grade 8 and F911.

Grade 8 - http://www.allensfasteners.com/detail.asp?Product_ID=0029

Grade F911 - http://www.allensfasteners.com/detail.asp?Product_ID=0049

ARP Black Oxide Flange Bolt Fasteners http://www.allensfasteners.com/detail.asp?Product_ID=0507A

All are in the same ballpark cost wise. I measured my existing bolts to ensure I was getting the correct length given my issues with the bolt holes.
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Re: MTS VT59 Shaft Rocker System with ARP Studs Clearance Issue

Postby Deano » Sun Mar 19, 2017 8:21 pm

The ARP black oxide (8740 Chromoly) is what you want.
I didn't go dig any out to measure them, but note that you're after three different lengths.

Ten medium ones for the inside rows, and
Two shorter for the ends and Eight long ones for the remainder of the outside rows.

In other words, be aware the eighteen other than the two short ones, are not the same length.
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Re: MTS VT59 Shaft Rocker System with ARP Studs Clearance Issue

Postby BigDaddyT » Mon Apr 03, 2017 7:59 pm

Looks like I have a solution to the problem with the help of Deano, Swamphunter, Buddy Branch, and others who commented. After talking to everyone it was determined that my head bolt holes were not threaded to the base of the hole. In discussion which Buddy, he was kind enough to let me know the exact lengths that I needed and even told me the ARP part numbers that were needed to get the studs short enough to work under the shaft rocker system. The only issue at that time was finding places that sell individuals studs in the correct lengths as I only needed 6 and (2) 12 point nuts. I found an internet site that listed the entire ARP catalog and ordered all that I needed. The particular bolts that i ordered were 1/2" shorter and had less threads on the block side (coarse threads) of the stud so that they would not go as deep into the hole as the standard studs. You can see the difference in the studs in the photo below. The longer one is 5.4" and the shorter is 4.9" in length. Thanks for all the help that everyone gave me. I believe that I can move on and maybe get this boat in the water in the near future.

Image
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