Head Bolt Length

[niap101]

I am assembling a hybrid, 1G 6-bolt block and 2G head (crankwalked). I have moved a couple of times since starting this project so parts might have gotten scattered. My problem: I have 12mm head bolts that are 4 inches long and they are too long. I think I need about 3-1/2 inch length. The block I am working with was from a non-turbo. I drilled and tapped and installed the 1G oil squirters in the block. Does this block require shorter head bolts? Have I made a mistake or do I just need the correct set of new ARP head bolts/studs? If so, which set? Does ARP have a website that lists specs? Thanks!

 

[ddavisaf]

10mm headbolts, however...
headstuds are simply that. They do not interfere with the rotation of operation of the head internals so it's your best bet.
ARP headstuds rock. Call up diamondstarmotorsports or slowboy and they'll get you the right ones.

For my own curiosity, what year headgasket are you using?

 

[92awddsm]

10mm headbolts, however...

What are you talking about? The 6 bolt block requires 12mm bolts or studs, not 10mm. The 7 bolt block requires 11mm bolts or studs. I am confused where you got the 10mm size from. WTF

If you are using a 6 bolt block, factory 6 bolt headbolts or 6 bolt arp studs should work for you. The length on the 6 bolt and 7 bolt headbolts and studs are the same. The only difference between the 2 is the diameter. I dont have any handy at the moment so I cant measure them for you but if the onse you have are too long, they are for an application other than the 4g63. Another thing to note is that some 2g heads need the bolt holes enlarged in order to accomodate the larger bolts. According to what Ive heard, some have been able to use the larger studs with no issues but in my own experiences, the 2g head wouldnt slide over the arp studs because of the increased diameter.

 

[ian7321]

Why did you tap in oil squiters? There is a reason that Magnus and some other big namers out there fill theirs in on their blocks.

1. They really dont do crap
2. They increase your oil pressure and help to lubricate everything more efficiently.

 

[niap101]

It appears to me (from everything I've read) that the 2G squirters ARE the cause for crankwalk. The squirters on the 1G block have a different oil supply than do the main bearings; therefore, the squirters do not directly reduce oil flow from the mains. I decided to install the 1G squirters to help with the extra heat of the piston caused by the turbo. If I was re-using the 2G block, I definitely would block the squirters. And if my memory is correct, I did have to ream the 2G head bolt holes slightly to accept the 12mm bolts.

 

[mavisky]

Why did you tap in oil squiters? There is a reason that Magnus and some other big namers out there fill theirs in on their blocks.

1. They really dont do crap
2. They increase your oil pressure and help to lubricate everything more efficiently.

Not everyone races in a 1/4 mile. Oil squirters help keep the pistons cool, which is nice after you've been driving it hard for more than 13 or so seconds. They also decrease oil pressure, not increase it. The next motor I build will have oil squirters, I don't currently because I fubar'ed a block beyond what I personally wanted to repair and am running an nt block with turbo internals for now.