Can you remove links in the cam chain to reduce slack?

[josh817]

I've been thinking about the slack in the cam chain when milling a head/block and I got to the point where if you milled enough the cam and cam tower would be shimmed up so high that you would have to get a longer valve stem to get back to a regular lash pad size. In turn you would have to shim up the valve springs. This problem would get worse if you use a reground cam where the lobe base is ground in to increase lift... Solutions? Obviously shimming will work to a certain extent. Or you could do something like Kameari where you adjust the slack and will work for up to 3mm of head shaving. You could combine the two, shim and Kameari idler gear type thing.

 

But then I was thinking. Is it realistic to break the chain and remove a link? I know we have that tool somewhere around here and use to use it on our Emmick carts but those were single row chains. I know my first thought is "you won't be able to time it properly without the proper amount of links" but I never used the links to time my cam. Aftermarket cams may not follow that timing anyway.

 

 

So I was curious, has anyone successfully removed a link in the chain to remove a lot of slack? 1 link is a lot of millimeters of slack needing to be fixed when I think about it...

Edited November 10, 2010 by josh817

[JMortensen]

Weld up the chamber instead of cutting the head would be the obvious solution.

[Tony D]

They do it on the 4 cylinder tall-deck L's when they convert from the Z to L head. Remove links from the LZ Chain set to make it work with the shorter L-Head.

 

Or so I'm told, this is all hear-say from a guy with an LZ24 bottom end with an L head up top. I ain't never done it, I ain't into crossbreedin' thems engins.

[josh817]

They do it on the 4 cylinder tall-deck L's when they convert from the Z to L head. Remove links from the LZ Chain set to make it work with the shorter L-Head.

 

Or so I'm told, this is all hear-say from a guy with an LZ24 bottom end with an L head up top. I ain't never done it, I ain't into crossbreedin' thems engins.

 

I'm considering because I'm planning on doing an L28 crank with my L24 rods along with 89mm pistons. Upon crunching the numbers, a wrist pin height like the KA24 of 34mm will yield around 9:1, I'd like to get into the 11:1-ish area. Since they will be forged I suppose I could say get a larger wrist pin height, which I plan on doing. However in the event that I can't do that, I'll deck the block.

 

Worst case scenario would be having to deck the block, head is already shaved, and then lobe bases on the cam ground down. That's a lot of slack so instead of buying a Kameari idler gear and trying to shim it all, removing a chain link could be an easier route. Which is why I'm asking.........

 

I'll need to CC my head one of these days. When disassembling it there were shims so I don't know if it had been cut or if the block was cut. I'd also like to install 46mm intake seats and 38mm exhaust, but I'm still pondering. Don't know if that idea will kill performance or not. Tony already knows I'll be going to fuel injection and he stated that a smaller port will be best for the velocity, I think. Huge ports would be best suited for carbs since they're restrictive. I'd like to do what Monzter did and use the big seats but a smaller valve. He too is running FI. I'll pick his brains soon enough.

Edited November 10, 2010 by josh817

[JMortensen]

I believe it is true to say that you would have to mill 1/2 the distance from one link to the next in order for the chain to fit correctly. You can measure a chain and see where that leaves you, but I think that's a whole lot of milling in order to make taking a link out an option.

[cygnusx1]

I believe it is true to say that you would have to mill 1/2 the distance from one link to the next in order for the chain to fit correctly. You can measure a chain and see where that leaves you, but I think that's a whole lot of milling in order to make taking a link out an option.

 

 

 

 

True but is there "cheating room" with the chain guides and tensioner location?

 

 

 

 

Redneck Dave says: "Get a bigger cam sprocket!" Yehaww   

Edited November 10, 2010 by cygnusx1

[z-ya]

If you have to shave a head that much because of warpage or detonation, you should find a new head. If you are shaving the head to increase CR, you should shave as much as you can compensate for when you shim the cam towers to keep the rocker arm geometry correct. If you need a higher CR, per Jon's suggestion, either weld the camber to reduce volume, or you can also run domed pistons.

 

Pete

[JMortensen]

True but is there "cheating room" with the chain guides and tensioner location?

I would guess no, based on what a complete ***** it can be to get the right size chain on with the guides moved all the way. Might be able to customize the curved guide to flatten it out a bit, but really, seems like there are other solutions here to take advantage of. I like Pete's domed piston suggestion too.

Edited November 10, 2010 by JMortensen

[Xnke]

I don't know about most other folks, but I would be wary of having a broken and relinked chain. It might never ever break ever, but I'd constantly be thinking about it.

 

I agree with Pete, domed pistons would be the way to go. Or have the head welded to a closed chamber head, to match the KA24DE pistons better. Isn't it John Coffey's N42 that had the open chamber and the domed pistons, to reduce valve shrouding while keeping the compression?

[JMortensen]

I don't know about most other folks, but I would be wary of having a broken and relinked chain. It might never ever break ever, but I'd constantly be thinking about it.

It's really not that big a deal, but one could start with that Mercedes chain that has a master link if it that makes it better. Don't ask me what Mercedes, I don't remember, but it fits the L series and was commonly available about 10 years ago.

[johnc]

I agree with Pete, domed pistons would be the way to go. Or have the head welded to a closed chamber head, to match the KA24DE pistons better. Isn't it John Coffey's N42 that had the open chamber and the domed pistons, to reduce valve shrouding while keeping the compression?

 

Yes. Very open chamber with lots of room around the valves. The pistons were domed JEs which gave 13.6 to 1 CR.

 

 

[Bob-omb]

I'm lookin' to do a similar big-bore build (w/ L28 block & crank, & FI) and hit the same wall when trying to find a high(er) compression solution. If you're doing custom pistons, you can always make up the difference in pin-height and piston dome, like others have mentioned.

 

However, I'm planning on utilizing custom rods (136.6mm, or L14 rods if I can find them - not likely) and VG30E pistons. This set-up will render a perfect ±0 deck-height, a 10.7:1 CR (w/ N42 & .6mm HG), AND a higher rod/stroke ratio (1.73:1, read: less friction), AND shorter pin-height and shorter overall piston height (also read: less friction), AND Sealed Power VG30E pistons are only $20 a pop. So, it's kinda like Robello's 3.0 kit, only it's cheaper, a few more mm oversquare (shorter stroke) and 2.9L.

 

Also, if you remove links, you'll have to remove at least a link-and-a-half, just like a bike chain. So, that could either be exactly what you need or waaaay too much; I dunno.

[josh817]

I don't want to be a butthole or anything but this wasn't about higher compression, it was about whether or not a chain link can be removed reliably. Sounds like we have a lot of hearsay about the topic. This is something that I don't want to try out personally... lol if it goes bad, it'll get real hairy real fast.

 

I think I have an old chain at home. I'll have to check this weekend.

Edited November 12, 2010 by josh817

[JMortensen]

Also, if you remove links, you'll have to remove at least a link-and-a-half, just like a bike chain.

Good call. I didn't even think about how the chain is built. So really the answer then I think the answer is no.