my build thread: 2 years in the making.

[m3jasper]

I like the seats...nice choice!

[montywilliams]

Very nice buildup so far.

I'm new to this forum but I wanted to comment on something I noticed in the short block build pictures you posted at the beginning of this thread. I noticed that the main cap nuts were not fully engaging the main cap studs. Assuming that the nuts were fully torqued down onto the main studs in your photos, the nut threads were not fully engaged on the stud and actually several nut threads were exposed. If this is correct, your main studs are too short. There should be at least 2 stud threads protruding past the nut. ARP actually recommends the equivalent of 1/2 the diameter of the stud.

Like I said, very nice build up, I'd hate to see you have a bottom end failure due to a fastener issue.

I've been building high-performance street and marine engines for several years, including turbo engines, and it caught my eye in your photos.

Since I'm new, I can't post photos or URL's, but if you go to
montygwilliams dot com you'll see some pics of a pumpgas 1200hp/1000tq twin turbo engine I built for an older Corvette that I drive around. I used a pair of Precision Turbo PT-52's, using 60-1 compressors and PTE's custom exhaust housing. I built/Tig'd it all in my garage as well.
Good luck.

[milKt]

uh oh,
tear it back apart.
dammit.

[Shuasha]

Very nice buildup so far.

I'm new to this forum but I wanted to comment on something I noticed in the short block build pictures you posted at the beginning of this thread. I noticed that the main cap nuts were not fully engaging the main cap studs. Assuming that the nuts were fully torqued down onto the main studs in your photos, the nut threads were not fully engaged on the stud and actually several nut threads were exposed. If this is correct, your main studs are too short. There should be at least 2 stud threads protruding past the nut. ARP actually recommends the equivalent of 1/2 the diameter of the stud.

Like I said, very nice build up, I'd hate to see you have a bottom end failure due to a fastener issue.

I've been building high-performance street and marine engines for several years, including turbo engines, and it caught my eye in your photos.

Since I'm new, I can't post photos or URL's, but if you go to
montygwilliams dot com you'll see some pics of a pumpgas 1200hp/1000tq twin turbo engine I built for an older Corvette that I drive around. I used a pair of Precision Turbo PT-52's, using 60-1 compressors and PTE's custom exhaust housing. I built/Tig'd it all in my garage as well.
Good luck.

Yeah, the studs that ARP makes for these engines are a bit short. My machinist told me to stick a small ball bearing or the like under the stud to bottom it out sooner. ARP really needs to make slightly longer main studs.

[s52e368]

Very nice buildup so far.

I'm new to this forum but I wanted to comment on something I noticed in the short block build pictures you posted at the beginning of this thread. I noticed that the main cap nuts were not fully engaging the main cap studs. Assuming that the nuts were fully torqued down onto the main studs in your photos, the nut threads were not fully engaged on the stud and actually several nut threads were exposed. If this is correct, your main studs are too short. There should be at least 2 stud threads protruding past the nut. ARP actually recommends the equivalent of 1/2 the diameter of the stud.

Like I said, very nice build up, I'd hate to see you have a bottom end failure due to a fastener issue.

I've been building high-performance street and marine engines for several years, including turbo engines, and it caught my eye in your photos.

Since I'm new, I can't post photos or URL's, but if you go to
montygwilliams dot com you'll see some pics of a pumpgas 1200hp/1000tq twin turbo engine I built for an older Corvette that I drive around. I used a pair of Precision Turbo PT-52's, using 60-1 compressors and PTE's custom exhaust housing. I built/Tig'd it all in my garage as well.
Good luck.

if your referring to these pictures they are NOT tq'ed (note the gap in the front cap)

[montywilliams]

I can see the gap between the main cap and the main web on those, I wasn't referring to them. The pictures I was referring to are in Post # 13 where the description lists the "main caps installed" and specifically Post #14, where it appears the windage tray is fully installed, and is described as such, and there are still exposed threads on the main stud nuts. Like I said, it's difficult to tell whether they are torqued or not, I was just bringing up a point I noticed. I think everyone would agree that it would be a shame if there were a fastener failure due to the lack of thread engagement and main stud stretch/preload. Without proper thread engagement, the torque preload could be lost and/or the threads that are engaged could be sheared off.

I couldn't find specific mention/recommendation of at least 2 exposed stud threads exposed past the nut, or the recommendation that the equivalent of 1/2 the studs diameter's worth of threads be exposed (a call to ARP would verify it though), but I did find this on the ARP website:

"An additional factor must be taken into account in defining the bolt configuration: the length of engaged thread. If too few threads are engaged, the threads will shear at loads that are lower than the strength of the bolt. As a practical matter, the thread length is always selected so that the thread shear strength is -significantly greater than the bolt tension strength."

Hopefully it's a non-issue as it was would surprise the heck out of me if ARP was selling studs that were too short. I've used their fastners exclusively for years, I actually helped them sort out a main stud kit when the Dart Iron Eagle/GM Rocket block was released.

[Shuasha]

Hopefully it's a non-issue as it was would surprise the heck out of me if ARP was selling studs that were too short. I've used their fastners exclusively for years, I actually helped them sort out a main stud kit when the Dart Iron Eagle/GM Rocket block was released.

Prepare to be surprised, they're too short.

[s52e368]

Prepare to be surprised, they're too short.

truth, its the same for most all the these builds..

if its an issue later, i can always pull the sub-frame and drop the pan to rectify

[5mall5nail5]

Strange - my studs fit great.

[montywilliams]

truth, its the same for most all the these builds..

if its an issue later, i can always pull the sub-frame and drop the pan to rectify

The problem is that if it becomes an issue, it'll be too late to "rectify" and removing the pan will be the least of your worries. If one of your main cap nuts loses preload or the threads sheer, the bottom end of you engine will be scattered along the road behind you. Give ARP a call and ask them what they think, I'll bet they'll say the same thing. I don't know how much you've got in your motor so far, I have $40k in my twin turbo, but I'm sure it's quite a bit. It would be a shame to hurt it due to the proverbial 10 cent part (or in this case $150 main stud kit).

As for the difference between the fitiment of the studs in your block and the one just posted above, your block may have been drilled and tapped just slightly deeper. ARP offers their studs in 1/4" increments, or several mm's in this case, you just need to get longer one's.

[s52e368]

Strange - my studs fit great.

jon you running the washers ?
doesnt look like it

[5mall5nail5]

I think so Carl - engine guy put it together and he's done so for a while, I don't have a better pic

[s52e368]

I think so Carl - engine guy put it together and he's done so for a while, I don't have a better pic

couldnt tell i was gauging from the "cap base thickness"

[montywilliams]

Sorry to be "Mr. Negative", but if he's not, that's a problem too. You need the washer to ensure that friction between the block and the underside of the nut isn't resulting in an incorrect torque reading. The friction will cause the torque to read higher than what is required to properly preload and stretch the stud.

[5mall5nail5]

I'll ask my engine guy tomorrow - I will go up. I can't tell honestly.

[s52e368]

Sorry to be "Mr. Negative", but if he's not, that's a problem too. You need the washer to ensure that friction between the block and the underside of the nut isn't resulting in an incorrect torque reading. The friction will cause the torque to read higher than what is required to properly preload and stretch the stud.

actually thats not correct either..

im on the phone with arp now and they said if not aluminum i can remove the washers. Technical Support: 800.826.3045

i also emailed him those pics in question, waiting for response.

[montywilliams]

[quote=s52e368;12194890]actually thats not correct either..

im on the phone with arp now and they said if not aluminum i can remove the washers. Technical Support: 800.826.3045

i also emailed him those pics in question, waiting for response.[/quotte]

"not correct either..."? What else is incorrect, that all the nuts threads should be engaged?

I realize there is assembly/moly lube under it, but not using the nut will have an influence on the final torque reading. If you question them, I'm sure they would say that ideally you should use the washers, but you could get away with it. Like any other business, they wouldn't go through the expense of manufacturing and including those washers in the kit if they weren't needed. ARP puts alot of effort into ensuring their washed are parallel ground, coated, and of consistent thickness and hardness. They're not typical hardware store, stamped, grade-8 washers.

However, during initial assembly, to ensure accurate torque readings, ARP recommends that the nut be torqued down 5 cycles. Torque the nut to the final reading in 3 increments, i.e. 30 ft lbs, then 60 ft lbs, then to the final 75 ft lbs as an example, then remove the nut, and repeat 4 more times. This ensures that the nut and stud threads are perfectly mated and helps overcome thread friction. The final torque sequence will result in a more representive indication of the studs preload/stretch rrather than the internal friction of the threads between the nut and stud or bolt.

This is all very anal, but it's straight out of ARP's catalog and installation instructions.

In any event, it's your engine. It's very nice, good luck with it.

[s52e368]

[QUOTE=montywilliams;12195012]

actually thats not correct either..

im on the phone with arp now and they said if not aluminum i can remove the washers. Technical Support: 800.826.3045

i also emailed him those pics in question, waiting for response.[/quotte]

"not correct either..."? What else is incorrect, that all the nuts threads should be engaged?

I realize there is assembly/moly lube under it, but not using the nut to have an influence on the final torque reading.

However, during initial assembly, to ensure accurate torque readings, ARP recommends that the nut be torqued down 5 cycles. Torque the nut to the final reading in 3 increments, i.e. 30 ft lbs, then 60 ft lbs, then to the final 75 ft lbs as an example, then remove the nut, and repeat 4 more times. This ensures that the nut and stud threads are perfectly mated and helps overcome thread friction. The final torque sequence will result in a more representive indication of the studs preload/stretch rrather than the internal friction of the threads between the nut and stud or bolt.

This is all very anal, but it's straight out of ARP's catalog and installation instructions.

ok well thanks for the info. ill look into it .. is that what you wanted to hear ?

[montywilliams]

Sorry, I was just trying to help, I certainly was not trying to be confrontational. Like I said, you've got a very nice engine, I'd hate to see it ruined because of a fastener. Good luck with it whatever you decide to do. I won't comment further.

[5mall5nail5]

carl they said in an iron block the washers aren't necessary?

[s52e368]

carl they said in an iron block the washers aren't necessary?

yes, (strange i know)

[s52e368]

Sorry, I was just trying to help, I certainly was not trying to be confrontational. Like I said, you've got a very nice engine, I'd hate to see it ruined because of a fastener. Good luck with it whatever you decide to do. I won't comment further.

well it seemed that way. but i am looking into it further and may have time this weekend to inspect it further.

[5mall5nail5]

Hm I'll ask Jim tomorrow

[dcvee]

Never seen an aftermarket main bolt without a washer. I would think that the harder bolt material would cut into the softer cast iron and skew the torque readings.

But, I'm not an engineer at ARP

Don

[s52e368]

direct response from ARP:

HI CARL,

YOU CAN REMOVE THE WASHER OR TURN OUT THE STUD A COUPLE OF TURNS WHICH WONT HURT A BIT

THANK YOU, GIL