Hello:
I am installing a roller cam into a 1969 427 block. I am measuring .025 end play and need to shim the cam button to get my desired .005-.009. I would like to use my stock cover but was thinking of purchasing the Cloyes cover with the adjustable button. I heard there can be some clearance problems with the stock water pump. Does anyone have any suggestions on how to shim the button and where I can purchase a shim?
Thanks
Tom

 

You can buy shims at McMaster Carr.
https://www.mcmaster.com/shim-washers/ring-shims-7/

Jebby

 

Thanks I just placed my order with them!

 

Stock tin cover not a good idea. If you need to space the pump forward they make extra thick water pump gaskets. The you will need a spacer on the lower pulley the same amount so belts will line up. Not a big deal though.

 

If you do use a stock tin cover you should make a filler block between it and the back of the water pump
M

 

I used the Cloyes on my 73 BB. It is a really nice piece. I had the stock pump on at first, and now I am running a Stewart stage 1. The cover is notched for the water pump backing plate bolts. I didn't have any fitment issues.

 

Its tight. I had to reduce the heads on a couple of the bolts on the back of the water pump, but it wasn`t much and I now have good clearance.

 

Thanks for all the advice. I was told by Straub Technologies that the stock cover would be fine with my setup. I will look into the Cloyes cover also.

 

Years ago before I knew better I machined a cast aluminum Cloyes adjustable button to clear a thicker higher volume water pump. Then I was told by a race engine builder that roller buttons are not needed if you have quality timing sets. Right after that conversation I was doing a refresh on my engine. I noticed upon tear down and I use the Crane billet timing set that my cams center button had never touched. Just think about it. quality double roller chains are hard to even put on and don't allow fore and aft movement of the cam. Nothing moves the cam back and forth. That was 20+ years ago and many engines later I still don't bother with roller buttons.

 

I bought a nylon cam button that advertised to be easy shimmed or "modified" for proper clearance as im going to doing a roller cam conversion myself soon.

 

I am running a Rollmaster double roller chain per Chris's recommendation. The shims should be delivered today so hopefully I will get everything set today. I appreciate the advice from everyone.

 

OMG!!! Here we go again about the roller cams supposedly walking forward, using a stock OEM timing cover, cam buttons, etc.

Listen to Gkull!!!!

I went through all of this dilemma and drama back in 2013/4 when i installed a howards Roller cam in my OEM L-82 SBC. Like Gkull states above and I thought the same when using a double roller timing chain which is SO stiff and rigid, "how in the world can the cam walk forward and bend that timing chain" ? Answer is, it cannot. The chain would snap first.

I reused the OEM GM timing cover as well with a Stewart Stage 2 aluminum water pump that is so tight against the stock OEM "tin" steel timing cover, I cannot even slide a piece of paper between the water pump and timing cover. There is no way that my OEM GM timing cover can flex from the cam walking if it could overcome the forces necessary to bend the double roller timing chain...NONE!

Lastly, I did install a nylon cam button by slightly dimpling the OEM timing cover to fit the nylon button once the came was installed with the double roller chain...no shimming, no endplay measurement, no clay/putty....The position was solely determined by the final installed roller cam lined up with the crankgear with the timing chain installed....those chains are super tight.......and will not allow any movement of the cam....

No issues now going on 7 years.......ZERO.....no special fuel pump pushrod or distributor gear..both OEM........go figure........

 

Save yourself a lot of grieve and read my post above and listen to gkull!

Lots of smoking mirrors and over complication of the retro roller cam install and the pushrod measurement myth as well......it really was quite straight forward and frankly pretty easy once you can see through the mystique propagated by some for moderate street motors....

 

I dont know if this was intended for the OP?
I already purchased the nylon cam button and had no real intention of doing anything special besides running the cam button under my existing cover I did buy a pushrod length checker since im running dart heads and got conflicting answers on this but read that while "close enough works" with pushrod length, that it could cause premature guide wear... that and the checker was about $15 shipped so..I also know the Howards cam is made of treated ductile iron so it would work with the stock fuel rod and dist gear.

 

You definitely need to measure the pushrod length with a roller cam (and get the correct length pushrod for your heads) but there are lots of different ways people measure the sweep of the rocker on the valve stem.....Sounds like you are all set, otherwise. Some of the stuff I read here on the forum back in 2013/14 gave me fits but it really forced me to evaluate the best method to install the roller cam and measure the pushrod length.....

 

Yes I went through the same thing when building my engine around that same time period... A lot of what I read here made me feel that it was beyond my capabilities both mechanically and financially when in reality It ended up being neither... My "aggressive lobed " flat tappet cam never gave me issues either.

 

One item that really throws pushrod lengths off is cam base circles.

 

The "Lunati" stud pushrod length checker and adjustable pushrod is better than nothing and is great for stock length valves, stock heads, etc......anything other than that needs light tension springs and dychem.
Pushrod length is even more critical in a daily driver simply because of total cycles......
Roller cams get roller buttons......period. There is a reason GM put lockplates on stock roller 5.0/5.7's in the 90's.......when the chain wears, it WILL move. That said.....I have a bolt on setup that gives me .010 everytime for small block. When the cam "walks", it puts undue sideload forces on the roller....not much spread over 16 lifters but multiply that by number of cycles and it matters. I personally don't think it is that big of a deal and for $20....why not just put one in? I have heard of people not using a button but I know of ZERO Pro builders that do not.......it is just one of those things you do, no question.

Jebby

 

Just to be clear, I am not saying using a cam button is not a good idea or good insurance...I DID use a cam button on my build.

Nor am I saying that a roller cam MAY walk if not appropriately secured with a double roller aftermarket timing chain, not talking about an OEM timing chain, whatever GM used back in the day or even today on their roller cammed engines from the factory.

I am still waiting for an explanation about how the stock GM OEM timing chain cover, sitting directly super snug against the GEN 1 SBC water pump, is going to supposedly flex with a retro roller cam, on a C3 corvette motor? It cannot.

As I stated previously, use a double roller timing chain, install a nylon cam button for insurance (dimple the cover to fit) with the Stock OEM timing chain cover (SBC GEN1), measure the proper pushrod length using a a pushrod checker, and you should be good to go.

FWIW-I did not use checker springs with my howards roller since Howard's provided me the dry versus the wet preload for the lifters. I factored the dry preload into the pushrod length calculated and ordered the proper length pushrod. I check the valve stem wear every season and, going on season 8 this year, there is zero wear on the valve stem in a perfect arc..go figure.......

 

I'm saying that Cloyes adjustable are not needed. The aftermarket water pumps have very little clearance. I use a central button that doesn't do anything except look pretty under a stockish type cover. I've never had one touch the inside of a timing cover.

http://www.speedwaymotors.com/Small-...Long,3232.html

My refresh going back in