Block interference with Edelbrock 7801 double timing chain?

[Tooky]

I got my new cam installed tonight and when I went to install my Edelbrock #7801 double roller, it seems like I'm getting some interference. When I change back to the stock cam sprocket, it rotates smoothly. I put a dab of assembly lube on the block where I thought it was hitting, and put the Edelbrock sprocket on. It left a tell-tale mark on the sprocket.

Is this normal? Is it safe and correct to grind the block with a die grinder? Obviously I'll have to make an "apron" or something to keep any shavings from going into the motor.

I bought this timing chain on a recommendation that everyone uses these in SyTys... I searched and couldn't find anyone else who has this problem. Did I forget something when I reinstalled the cam? I put the cam in, the dark blue torx-bolted retainer plate, and then put the timing sprocket directly on that, seating the dowel pin. If there was something that fits between those two, I'd have enough clearance.

 

[James Thomas]

Re: Block interference with Edelbrock 7801 double timing chain?

Sorry Tooky, I never have used a Edelbrock timing set. Comp or Cloyes and no trouble with them. If I had to say it was a parts problem, then I would lean to the cam gear since your engine ran fine with the stock timing set and didn't fill you engine with steel shavings. Lay a straight edge across the crank and cam gear and make sure they are lined up. Beyond that, swap in another locally available double roller and see how that fits? Maybe a bad gear cause I doubt the block is off, assuming that all is installed correctly and the cam is correct. May want to look at your old cam thrust plate as compared to the new one (looks new anyway).

___________
James

 

[Sy-1177]

Re: Block interference with Edelbrock 7801 double timing chain?

I just put the 7801 on my Ty. Now granted it doesn't run but I don't believe it was hitting anything. It was VERY close to hitting the cam retaining bolts, but just cleared them! No problems with the block though.

 

[CKEITH]

Re: Block interference with Edelbrock 7801 double timing chain?

since the sprocket is only hitting in that one small spot as it is rotated...i would think that the sprocket is the issue or it's not seated completley flat on the cam. maybe a small piece of dirt is causing it to sit ever so cockeyed.

 

[George Blake]

Re: Block interference with Edelbrock 7801 double timing chain?

I don't think he rotated it.

I think he put the lube on and then installed the gear to see if it hit and sure enough it did. It's possible the design changed and you may have an interference issue now. Call them up and tell them what going on and email them pics and see what the manufacturer recommends. They would probably be pretty interested. Then again, they may just tell you to grind a little off.

 

[nallj92]

Re: Block interference with Edelbrock 7801 double timing chain?

my other block is ground there for a double roller, should be fine

 

[ashman]

Re: Block interference with Edelbrock 7801 double timing chain?

that looks like the same stuff that was coming out of your steering wheel

just kidding...grind'er down!!!

 

[phunk]

Re: Block interference with Edelbrock 7801 double timing chain?

is there any chance that you are putting the cam gear on backwords? maybe if you flipped it the offset would be different?

 

[Tooky]

Re: Block interference with Edelbrock 7801 double timing chain?

OK I just got back from the garage. The block cut like butter! It didnt even squeal, must be some soft metal. After I got it all taped up/protected, the actual cut took about 15 seconds altogether. Here's what I ground off the block:

Here's how it fits now. Plenty of clearance!!

Now it turns smoothly. :thumbsup:

PS: For future reference; see discussion of this same topic in my Vortec heads and cam install thread, I included a link or two to a Carcraft magazine article showing the same grinding done on a Small Block Chevy.