ARP head studs

LMWatBullRun · **Posted:** Sat Sep 21, 2013 7:44 am

The only compelling reason for the recess milled into each of the head bolt holes in the head is for installation of a high strength washer to go under a given bolt length. VM Motori could easily save machining costs by eliminating 18 machined recesses and simply using longer bolts with high strength washers under them; there is plenty of vertical clearance for the added ~5 mm of height.

My guess is that the decision to eliminate the bolt washer was made relatively late in the engineering/production cycle for this engine design, probably under pricing pressure from DC. They eliminated the cost of 18 washers and probably bought a shorter bolt, too.

A slightly longer stud, say about 5 MM or so longer, combined with a machined stepped washer that engaged both the primary bearing surface inside the recess and the shoulder outside it, perhaps 1 1/4" wide would provide significantly better compression on the head and reduce the stress on the aluminum around the holes. I've toyed with the idea of pursuing this further, but the base stud install seems to do everything required, so I'm doubtful this would add any real benefit for the added costs. If VM is watching this thread, and I expect that they are, there's a free tip for the future if you want to wring more performance out of a really small block. :lol:

It begins to look to me that at some point VM Motori may have switched bolt providers and/or slightly modified their machining process, as reports from the field and the photographs I have seen suggest that later production motors have a slightly wider head bolt bearing surface and slightly wider machined recesses. One member recently advised that the milling cutter I lent him actually fit into the recess, and my recollection is that it would NOT fit into the recesses in the head that I have. Once I get the cutter back I will look into that some more and try to confirm.

One of the other mods I DO plan to investigate is rod bolts. ARP sells very high strength rod bolts and I intend to do a detailed post mortem on Geordi's motor whenever I get the time to pull it and look at it. It's clear that there was some sort of failure of the rod system that precipitated his field installed ventilation hole, and I want to look into that thoroughly. It may be that high strength rod bolts will add some margin there too. I will report more when I have something to report.

geordi · **Posted:** Sat Sep 21, 2013 1:31 pm

Larry, you know already that I will be VERY interested to see what you discover when you pull that motor. Depending on the schedule, I might be available to come back up there and poke at it myself with you. What I suspect - and this is what I hope you can validate or refute - is whether the rod bolts themselves simply backed out of their bores and are laying in the oil pan.

The rod end that is visible and jammed in the side of the block did not show any obvious signs of trauma beyond getting shoved through a 1/8" thick wall. The bolt hole looked immaculate to me. I'm curious to know about the other one on that rod, if the bolt is still in place or backed out and bent like the single remaining bolt was on engine #1's failure. THAT failure had a lot more unhappy metal-chewing sounds preceding the failure. The engine you have... Was idling along (and tapping) and then it wasn't. Poof, that fast, with no unhappy sounds other than the tapping.

Back to the studs for a moment.

We didn't get a chance to show you the fit of the cutter in the head recesses, but you are correct: It did fit without any modifications needed. Further than that - We elected to just move forward without using it, as the lip that the cutter was for, seems to be caused by that rounded edge of the factory bolts. Does the head locally yield under factory installation? I do not know. The ARP washer fit the factory recesses just fine, and if you put the ARP washer onto the factory bolt, the difference in size is microns at best. What the ARP washer has is a square edge, compared to that slight rounding of the shoulder of the factory bolt.

Installation proceeded normally for many of the holes, however I believe it was a total of 4 of them that I could feel the 'ridge' being compressed. I got to the point where I knew the feel (calibrated elbow :wink:

) and expected the wrench to click on the next pull... And on those 4, the 'next pull' instead I could feel the pressure reduce and then start to build again - local yielding. I got about 2 more pulls from each one, then the wrench clicked. One of the ones that did this was the forward-left-most hole. Yep, the one right between those two lifter sockets. Both lifters were able to still be removed and reinstalled with the same effort and feel as any other lifter. No damage or yielding outside of the hole, so that was the ridge crushing.

The scenario was the same for the stud installation in Boston, the only difference being I only felt two ridges crush. Obviously there is some variation in how these were installed from the factory. Both of these CRDs now have studs installed to 130 and 120 lbs. I do have a video of the before / after of Boston, and here are the links:

https://dl.dropboxusercontent.com/u/544 ... Before.mp4

https://dl.dropboxusercontent.com/u/544 ... -After.mp4

user113 · **Posted:** Sun Sep 22, 2013 12:16 am

Larry,

The rear timing belt cover on my jeep seems to have a production date code of January, 2007 (see viewtopic.php?f=5&t=76821) which may well support your theory of larger machined recesses in later models. I don't remember looking at any date codes on any other parts we took off that day.

geordi · **Posted:** Sun Sep 22, 2013 12:30 am

user113 wrote:

Larry,

The rear timing belt cover on my jeep seems to have a production date code of January, 2007 (see viewtopic.php?f=5&t=76821) which may well support your theory of larger machined recesses in later models. I don't remember looking at any date codes on any other parts we took off that day.

Which also supports our theory that someone else was inside your motor before you bought it, because you have the Euro-style inner cover design as well.

dgeist · **Posted:** Sun Sep 29, 2013 4:38 pm

Some other sources google found:
http://www.sears.com/arp-204-4706-vw-audi-1.9l-turbo-diesel/p-SPM7621348108P?PDP_REDIRECT=false

http://www.mjmautohaus.com/catalog/product_info.php?info=ARP_204-4706_Head_Stud_Kit_Revised_Performance&products_id=4069

http://www.amazon.com/ARP-2044706-Diesel-Volkswagen-Engine/dp/B007FH8WNS/ref=aag_m_pw_dp?ie=UTF8&m=A28AN1ND8QJID5

The last (and cheapest) is a retailer using Amazon but does not offer free shipping (with a prime account).

Dan

audiboy86 · **Posted:** Wed Oct 02, 2013 8:59 pm

Head stud kit at 145.53 and they shipped out extremely quickly and didn't charge my account till they had shipped.

user113 · **Posted:** Wed Oct 02, 2013 9:30 pm

audiboy86 wrote:

Head stud kit at 145.53 and they shipped out extremely quickly and didn't charge my account till they had shipped.

Hmmm...I was extremely disappointed in their service when I ordered mine from them. I ordered two boxes of studs on August 16, 2013. As of August 26 they STILL had not shipped. I called the customer service number 20 minutes before closing time and got to the point where I was "next" in the cue, then at closing time the line just went dead. I called the next day, they said that the computer had screwed up and not completed the order to move it to the fulfillment department. They were very sorry and offered to "next day" it at no additional charge. I told them that next day was not necessary. The shipment arrived on August 30, but there was only ONE box of studs. I called them again, again they apologized and offered next-day shipping upgrade on the other box. Again I declined it since I didn't need them for another week. The second box arrived September 4. I logged into my Autoplicity account just now and it still reads:

Order Number: 108876
Order Status: Received, Pending Shipment
Order Date: 8/16/2013 9:28:37 PM
Order Total: $299.11

I am glad you had better luck than I.

user113 · **Posted:** Thu Oct 03, 2013 8:35 pm

Oh, yeah. One more thing; I just checked the bill. They charged my credit card on 8/16!

dieselguy · **Posted:** Mon Dec 09, 2013 11:46 am

hey guys I have a question for you. I purchased a libby with a supposedly bad engine. the guy who owned it was supposed to be a mechanic but he was running plain 15-40 diesel oil in this engine and had never done a tb or egr delete. the engine started running rough and he thought it might have jumped time. he timed the engine properly to find it hadn't jumped. when he took the intake off he found that several of the ports was so clogged you couldn't even get a pencil in the hole. now here is the amazing part. its got 200,780 miles and he has never touched it besides a new turbo and alternator. I bought it cheap and its in almost immaculate condition. It was going to be a winter project for him but due to family issues he posted it on craigslist and sold it. once I got it home I found that the rockers were toast and cams had some wear "which I assumed was from regular heavy weight diesel oil" but after hearing the stories on here looks like it was probably a champ to make it this far. I have also purchased another engine from a wrecked libby with 100,000 miles, im going to stud the top and bottom end of this one but in meantime im going to swap rockers and intake with cams onto to high mileage engine with a good port clean and egr delete and see what it does. now I have read every thread on this head bolt issue, I have never heard this engine run but since im at the head bolts Im thinking about retorking. im not going to spend and money on this engine at this point not knowing what im getting into but should I check the tork or leave well enough alone and see if it runs. sorry for such a long post but I felt you needed to know the whole pic of what im doing.

dieselguy · **Posted:** Mon Dec 09, 2013 11:52 am

one more thing I didn't mention, the engine I bought was from a wreck and it busted the timing cover and one timing sprocket.

im looking for some bent valves but keeping my fingers crossed. I paid core price for a complete 2006 crd with everything attached so what the heck, I can buy some valves and even a piston if need be. :wink:

so that's one reason im pulling the head plus I want to get a hot tune and turbo kit from green diesel and see what this thing will do :JEEPIN:

GreenDieselEngineering · **Joined:** Sun Jun 07, 2009 5:10 pm **Posts:** 1111

dieselguy,

Keep using the stock engine with 200,000 on it. Just install new rockers and clean the intake. A retorque of the head bolts can't hurt at this point. How bad are the cams? Many times you can just keep using them if there is just some glazing or normal wear. We have a full rocker/lifter set for $300 and this is way better than using older rockers from the spare engine. 15W-40 is fine for the VM engine during the summer months anyway.

dieselguy · **Posted:** Mon Dec 09, 2013 1:54 pm

well there was a cpl lobes, im thinking exhaust side,,that had some noticeable wear, I figured since im taking the other engine apart anyway and its setting right in front of the libby id just swap to see if its gonna run, plus intake on wrecked engine isn't gummed and I wouldn't wont to run a set of good lifters on a cam with a noticeable groove. I was just gonna stick the rockers over on it but it will be easier just to set it all on. I always run the best full synthetic oil and full synthetic Lucas. I know, some ppl say its a waste of money running synthetic oil plus synthetic Lucas but for $15 bucks when I change my oil its just good piece of mind for me. I have ran the same oil mixtures in my cummins and put over half a million miles on them. as a matter of fact the last one I sold had almost 500,000 on it running 700rwhp, it had several oil leaks so the guy pulled the engine and was going to do a set of rings and bearings. his mechanic advised it would need a new cam because those engines with that many miles always wore the cam. they got it apart and found no more than 2 thousandths wear on anything, so they stuck it back together with the old parts, put new gaskets on and its still going up and down the road today. thanks for responding, I will be getting with you guys shortly for some goodies. I was curious, have you ever saw anyone run a set of compound chargers on one of these. the libby had a brand new charger installed right before I bought it and im wanting to get the turbo kit you guys sell and thought its a shame to have this stock turbo collecting dust :idea:

geordi · **Posted:** Mon Dec 09, 2013 2:20 pm

Keith's turbo kit is amazing, and well worth the money. The engine won't take a lot of abuse however, I can unequivocally state that the bottom end won't hold up to more than Keith's programmed boost levels. Compound turbos and more than 26 psi is just asking to ventilate the block.

I support your idea of just moving the valve cover and cams from the wrecked engine, that would be great. But don't use old rockers / lifters. Buy the set for $300 and run fresh. The head bolts can be re-torqued in place, just loosen each one in turn and set it as follows: The center lines around the pistons get 130 lb-ft of torque, the outer lines get 120 lb-ft.

Despite all documentation to the contrary, the factory bolts ARE NOT STRETCH BOLTS in this application. More than 130 lb-ft on the bolts, and you risk crushing the HEAD itself. The bolts will never yield.

dieselguy · **Posted:** Mon Dec 09, 2013 4:39 pm

lol,,yea im starting to see this isn't a cummins. think im going to stick with what available and shoot for the best. its sorta sad the potential this engine has to be limited to what it is. I researched this engine and found that cummins ships these on cargo ships over here bare block and puts a single overhead cam, with a timing gear set like the 4bt and puts these things in boats running 250hp with 495ftlb torque. the engine actually says cummins on top of it. I think ill run this one till she dies then drop my fresh one in. after it dies ill probably be ready to trash it anyway. it disgusts me to see diesels destroyed to the point they have been all in the name of env@@@@ist propaganda to make the rich even richer. wow how society has been dumbed down. oh well that's another forum lol.

geordi · **Posted:** Mon Dec 09, 2013 7:32 pm

Stop. Back up.

Cummins? Using THIS block? VM Motori block. Casting model 428. With their own head / cam / etc?
I want pics and part numbers or this didn't happen.

I'm not saying you are wrong, but this seems beyond strange to me. I've seen this block intimately. I don't see HOW the bottom end or the block itself could put up with the cylinder pressures to create those kind of numbers, to say nothing of the oddity of Cummins purchasing raw iron from a competitor to put their tops on.

VM uses these engines in marine and industrial (generator, pump, etc) type of applications elsewhere in the world, and there have been rumors for them existing in Chrysler minivans and the ubiquitous black cabs in the UK. This would be the very first mention anywhere of this block wearing a Cummins hat. Why would they do this, when Cummins casts their own blocks just fine for every other application?

racertracer · **Posted:** Mon Dec 09, 2013 9:18 pm

geordi wrote:

the factory bolts ARE NOT STRETCH BOLTS in this application.

What does VM say they are?

dieselguy · **Posted:** Tue Dec 10, 2013 1:03 am

I'll work on some info for you. I actually had a pic saved at one time of a cargo ship stacked with thousands of these engines on them headed to Cummins plant.

dieselguy · **Posted:** Tue Dec 10, 2013 1:12 am

Here is a copy and paste from the hull truth boat forum. You can read up some there, its sold through mercruiser .they're very common.
Posts: 411The Cummins QSD Diamond Series are indeed VM blocks with Cummins trappings. We switched from Volvos to QSD 350's in our boats a little over 2 years ago. We have a pair in our current demo boat with 400 hrs on them and they have been flawless. From our customers' standpoint, the reliability has been great and the only complaint has been the cost of the filters. Cummins say they are working on reducing this cost, presumably with reuasble cannisters. We are much happier using Cummins products, not to mention the weight and space savings. Fountain is also installing QSD's as an option in their 38 with outdrives.

dieselguy · **Posted:** Tue Dec 10, 2013 1:21 am

SAMPLE SHIPMENT CONTACT CUMMINS MERCRUISER DIESEL...

SAMPLE SHIPMENT RECORD FOR CUMMINS MERCRUISER DIESEL MARINE

Sign up to view all of Cummins Mercruiser Diesel Marine imports.

Shipper

VM MOTORI SPAVIA FERRARESE 29 CENTO 44042 IT PH 0039 51 6837511 FAX 6837521

Consignee

CUMMINS MERCRUISER DIESEL MARINELLC CUMMINS, INC. P.O. BOX 290909 NASHVILLE TN 37229 US PH / FAX 615 986 2579

Product Description

MARINE PROP ENG, UNDER 111.9KW

Arrival Date

2008-06-22

Weight

10497 KG

Units

Port of Loading

Genova

Port of Discharge

Charleston, South Carolina

Vessel Name

MAERSK MADRID

Bill of Lading

CEVVOA55080585

Voyage No.

00810

Carrier Name

MAERSK MAD

Carrier Name

CEVV

Marks and Numbers

CUMMINS MERCRUISER DIESEL MARINE

dieselguy · **Posted:** Tue Dec 10, 2013 1:27 am

Cummins, Detroit, and Chrysler own part of the company. As a matter of fact there's a huge write up in my this months diesel power magazine about Chevrolet dropping their stock it the company since the new Dodge ram 1500 trucks are using this VM motori v-6 diesel.
I have a pic of the single overhead cam marine version but I'm not sure how to get pics on here from my phone

ARP head studs

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