therabidweasel

iTrader: (5)

Gents,

The Reactor and Circle D flexplates both appear to be about ~0.160" thicker than OE in the crank bolt area. RPM suggested that I use ARP flywheel (not flexplate) bolts as they should be longer. However, Jegs says the underhead length of the flywheel and flexplate bolts are the same, summit says the flexplate bolts are actually 0.080" longer, and the ARP website is of course useless.

I'd like to hear from folks that are actually running one of these aluminum flexplates what bolts they're using and if I should consider something else entirely. . .it just seems a little wrong to me to use an OE replacement bolt when what I need is ~0.160" longer to have the same thread engagement.

Steve

Links to the bolts for future reference:

Flexplate:
http://www.jegs.com/i/ARP/070/244-2901/10002/-1

http://www.summitracing.com/parts/arp-244-2901


Flywheel:
http://www.jegs.com/i/ARP/070/330-2802/10002/-1

http://www.summitracing.com/parts/arp-330-2802

mrvedit

OOPS - I see you are referring to Flexplate to Crank bolts. See below, but I leave this in for others...

See this thread for discussion about getting the converter-to-flexplate gap right and discussion about bolt lengths:

https://ls1tech.com/forums/automatic...ter-bolts.html

Yank said that stock is 12mm; and 16mm for SFI (thick aluminum) flexplates.

If you are in a hurry:
Personally I use Grade 8.8 or 10.0 of 20mm length from the local store, trying to match them for weight. I then add a thick washer on the engine side of SFI flexplate
and need a washer to get the gap correct. (I match all washers by thickness.)

If using anything longer than the suggested 12mm or 16mm, I would suggest testing the length by bottoming it out in the converter and measuring how much the flexplate and washers need to make up. You want to be absolutely sure the bolts do not bottom out before they reach full torque (and stretch a bit).

And remember to Red Loctite the bolts for final assembly.

mrvedit

OOPS - I now see you are referring to Flexplate to Crank bolts.
This has been fully discussed in these threads:

https://ls1tech.com/forums/automatic...ate-bolts.html

https://ls1tech.com/forums/automatic...ate-crank.html

The 2nd one has the ARP part number for SFI flexplate bolts.
In the 1st one, CircleD lists the equally good bolts they sell in various lengths.

Circle-D

iTrader: (21)

http://www.circledspecialties.com/p-...ank-bolts.aspx

We have some custom ARP bolts, mrvedit linked to them. Above is a link on our site. They have an under head length of 1.150. Be happy to answer any questions you have...

Chris

therabidweasel

iTrader: (5)

Oh yeah...now I remember. Cool, ill give you a call monday...I have some questions for how my tune should treat the stall anyway and want to see if the bolts you gave me with the converter will fit the plate. Thanks Chris (and Ted).

therabidweasel

iTrader: (5)

OK bringing this back for some additional advice. I bought the CDS bolts. As expected they are slightly too long and bottom in the crank when used with the reactor flexplate. Chris said that I could shim with washers, so I purchased a set of hardened 7/16" washers that fit nice and clear the chamfers on the ARP bolts.

I'm all ready to put it in, so I hop on ARPs site and get the directions/torque values for the standard LS1 kit (330-2802) and wouldn't you know in big bold letters it says not to use them with washers, and doing so voids the warranty.

My feeling is this is a CYA for failure resulting from too little thread engagement. I could grind them down, but it just seems wrong to do with ARP hardware. What do you guys think?

mrvedit

Personally I would not grind them down and would be comfortable using washers. Just remember that the bolt will stretch a bit as you torque it and even with a thin washer might bottom out before full torque is reached.

Especially if Chris knows that other have had success with the washers.

therabidweasel

iTrader: (5)

Thanks thats pretty much my thinking as well. I believe I have about 0.050" for stretch...cant say im super comfortable with that. Ill measure a few more times, would like a little more room.

I was hoping Chris would chime in but I dont really expect he has much experience with the non-CDS reactor plate with the CDS bolts...I should've bought the CDS version plate and been done with this. I do trust what he told me before, I just dont necessarily trust my memory of it, especially in light of the arp warning, and was looking for some confirmation.

Update
With no washers or flexplate the bolts bottom on the unthreaded part of the bolt shank, not inside the crank. Flexplate is 0.310" thick in the bolt area. Washers are 0.065" and with them installed I have 0.257" left under the head. So this gives me 0.053" (1.3mm) for stretch. The bolts are M11x1.5 so thats 0.67mm/turn or just under 2 turns when torquing from hand tight until they bottom. This was sufficient for me.

Circle-D

iTrader: (21)

Sorry, missed this thread... But I agree with you, you should have plenty of room for clearance. And I have several guys using a washer, you will not have any problems.

Chris

therabidweasel

iTrader: (5)

Thanks Chris. I appreciate the reassurance. Its all bolted up and ready for that cleaned up 4C.

Looking forward to that first lockup and seeing what itll do at the track.