Camshafts almost done - Page 2 - ZR-1 Net Registry Forums

Locobob · 03-17-2010

Quote:

Originally Posted by Polo-1

that's better..... I was thinking you were going to try a .750 + lift

And if he was then you'd have to go for .800 lift wouldn't you Kev

Polo-1 · 03-18-2010

I think my bank roll has hit it's limit

on the LT5

tpepmeie · 03-18-2010

Quote:

Originally Posted by Locobob

Details Todd, details!!!

Tool steel billets. With proper hardness. Specs to complement my heads and engine combination... Those aren't finalized yet. If you saw the size of my valve reliefs, I expect lift will be "up there". Designing for peak power at 7k, with a useful powerband 4000-7200.

Will advise of the company doing them once we know they will work, and hold up. Lots of horror stories out there about billets.

Todd

Jagdpanzer · 03-18-2010

Todd
I'm sure all will go well with cams
With the thoroughness you've approached this project the results should be outstanding and well worth the effort. I know many like myself have been following your project with great interest and really appreciate your willingness to share your experiences along the way with us.

Phil

flyin ryan · 03-18-2010

Quote:

Originally Posted by tpepmeie

Lots of horror stories out there about billets.

Todd

Really....Why? Not heat treated properly?

tpepmeie · 03-18-2010

Cam guy called today. Heat treat is done. He wants to know what the factory specification is for the cam bearing journals. He can copy the oe cams, but would prefer to put it exactly in the middle of the tolerance. I know this dimension stackup was the root cause of the cam seizures early on. Anybody know the tolerance? Perhaps Graham?

Todd

Jagdpanzer · 03-18-2010

Not sure that it matters, the heads you will be using on this build are the later Dunns, right?
My 94 FSM specifies the cam journals at 28.96 - 28.98 mm so 28.97 +/- 0.01 mm should work.
I imagine the clearances are fairly tight in the cam cover/cylinder head cam shaft bores.

Locobob · 03-18-2010

Quote:

Originally Posted by tpepmeie

Lots of horror stories out there about billets.

Todd

Yes there are, which is why I'd like to hear the details of your venture. If things go well it could open the doors to a new round of modding. Kudos for taking the lead in this.

flyin ryan · 03-18-2010

Quote:

Originally Posted by tpepmeie

Cam guy called today. Heat treat is done. He wants to know what the factory specification is for the cam bearing journals. He can copy the oe cams, but would prefer to put it exactly in the middle of the tolerance. I know this dimension stackup was the root cause of the cam seizures early on. Anybody know the tolerance? Perhaps Graham?

Todd

Do yourself a favour Todd & send him your stock cams to measure. Not un-common for all shops/machinists to measure things a hair this way or that way...

tpepmeie · 03-27-2010

Here's a few pictures of the setup piece. Sent it to me so that I can check clearances and start grinding the head / cam cover to clear this big lobe. This setup piece is just 4340 steel billet, while the finished pieces will be high grade tool steel. The challenge right now is finding the right springs. Problem is finding a light enough spring with the right installed height, able to take this much lift. We don't need much spring pressure for these, only about 70 lbs on the seat, and 140 or so at full lift.

03-18-2010	#12
Polo-1 Join Date: Sep 2005 Location: Washington Posts: 955	Re: Camshafts almost done I think my bank roll has hit it's limit on the LT5

03-18-2010	#14
Jagdpanzer Join Date: Apr 2007 Location: Northern VA Posts: 2,661	Re: Camshafts almost done Todd I'm sure all will go well with cams With the thoroughness you've approached this project the results should be outstanding and well worth the effort. I know many like myself have been following your project with great interest and really appreciate your willingness to share your experiences along the way with us. Phil

03-18-2010	#16
tpepmeie Join Date: Aug 2005 Location: Fishers, IN Posts: 815	bearing journal spec Cam guy called today. Heat treat is done. He wants to know what the factory specification is for the cam bearing journals. He can copy the oe cams, but would prefer to put it exactly in the middle of the tolerance. I know this dimension stackup was the root cause of the cam seizures early on. Anybody know the tolerance? Perhaps Graham? Todd

03-18-2010	#17
Jagdpanzer Join Date: Apr 2007 Location: Northern VA Posts: 2,661	Re: Camshafts almost done Not sure that it matters, the heads you will be using on this build are the later Dunns, right? My 94 FSM specifies the cam journals at 28.96 - 28.98 mm so 28.97 +/- 0.01 mm should work. I imagine the clearances are fairly tight in the cam cover/cylinder head cam shaft bores. Last edited by Jagdpanzer; 03-18-2010 at 09:06 PM.

03-27-2010	#20
tpepmeie Join Date: Aug 2005 Location: Fishers, IN Posts: 815	Re: Camshafts almost done Here's a few pictures of the setup piece. Sent it to me so that I can check clearances and start grinding the head / cam cover to clear this big lobe. This setup piece is just 4340 steel billet, while the finished pieces will be high grade tool steel. The challenge right now is finding the right springs. Problem is finding a light enough spring with the right installed height, able to take this much lift. We don't need much spring pressure for these, only about 70 lbs on the seat, and 140 or so at full lift.