[HWYSTR455]

I honestly can't recall the last engine that I had with press in pins. Has to have been in the 80s when using TRWs....


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[scott70]

Originally Posted by HWYSTR455

I honestly can't recall the last engine that I had with press in pins. Has to have been in the 80s when using TRWs....


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Everyone use floating pins? Which rods would you recommend? If I was going to make a change I’d have to do it soon. Thing is would I have to change pistons? They’re autotec… if I remember right the pistons came with spiral clips but obviously I didn’t use them and I don’t know where they are.

[HWYSTR455]

Originally Posted by scott70

Everyone use floating pins? Which rods would you recommend? If I was going to make a change I’d have to do it soon. Thing is would I have to change pistons? They’re autotec… if I remember right the pistons came with spiral clips but obviously I didn’t use them and I don’t know where they are.

Well. Rods & pistons would be like $1500 give or take, not sure it's worth it. Another $750 and you get a balanced stroker kit w bearings & rings.

You could have your rods bushed and pins fitted, and locks are pretty standard, inexpensive, even if you got a set from Autotec. That on top of your existing machine work is still not inexpensive. You're probably better off just going with what you have at this point, to avoid project creep.

You could estimate the costs between the different approaches and see where you're at, then make a decision, but the easiest would be to just use the parts you have.


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[scott70]

Originally Posted by HWYSTR455

Well. Rods & pistons would be like $1500 give or take, not sure it's worth it. Another $750 and you get a balanced stroker kit w bearings & rings.

You could have your rods bushed and pins fitted, and locks are pretty standard, inexpensive, even if you got a set from Autotec. That on top of your existing machine work is still not inexpensive. You're probably better off just going with what you have at this point, to avoid project creep.

You could estimate the costs between the different approaches and see where you're at, then make a decision, but the easiest would be to just use the parts you have.


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Wrong or right I said the hell with it and ordered some molnars,, 4340. , bushed for floating pistons. Shouldnt I be able to use my existing autotec pistons?...I looked for the spiral clips that came with them but obviously never used… long gone.I’ll try to sell my 4130s and recoup some of the money. The molnars were 730.00 and come with arp 2000 bolts installed. If anything it makes me feel better,, lol. Overkill I’m sure.

[HWYSTR455]

Yes, you can use the Autotec pistons, the small end needs to have the pin fitted to match the pin size/clearance spec is all. Locks are usually pretty standard, and can source from Autotec if there's a concern. Some pistons call for 2 locks per side, can look that up by the part number or ask Autotec.

Since they are going to check the balance anyway, it shouldn't matter if the rods are diff weight than the previous set. If the machine shop has good notes, they prob already have the bob weight determined and can match the rod weight of the originals.


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[scott70]

Piston paperwork

[HWYSTR455]

Yup, info is there, uses a standard wire lock so it only needs one for each end, spiral locks sometimes require 2 (or more).

Part number is there (990-072-WL), should be cake to order, the numbers dictate wire diameter and length. You need 16, obviously.

Here's some Wiseco ones at Summit:

https://www.summitracing.com/parts/wis-w5242

Clearance is also on the sheet, .003 , but if you want you can call RaceTec and ask. May want to make sure there's nothing special about the lock, but kind of doubt it. (Still better to be safe).

There's some general instructions in the RaceTec/AutoTec catalog on page 67, may want to provide that to machine shop if you don't have complete instructions:

https://drive.google.com/file/d/1-f3...KTZaEy7E6/view

Can ask your machinist if he needs any additional info, but seems straightforward.


EDIT: Pin diameter and wire diameter.


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