tysen86

so, '91 22RE, in 2004 it was built and we shaved .010 off the block along with .010 off the top of the head. Now here we are again, 10 years later, building the little 22RE again. This time, to get the head back flat, we had to take .008 off the bottom of it. Now, the cam and the crank are .028 closer together. my question is this:

Do I need to use an adjustable cam gear?

It will get a new timing chain set with steal guides to hopefully keep the chain from slappin around to much. any thoughts?

jimbyjimb

iTrader: (1)

Get a head shim.

The adjustable timing gear will only allow you to adjust your valve timing easily, it will not absorb slack in the chain. Shims maintain the proper spacing. Your machinist should be able to tell you how to install it and what size you'll need. It's easy, just an additional step in the gasketing process.

tysen86

Ya, I know that's an option, however I also know that my 22RE along with a lot of other ones on the road, have plenty of issues with head gaskets. I'd hate to add more to that area if I don't have to.

Anyone had any luck with head shims?

Terrys87

iTrader: (1)

I have never used a shim so no experience with that. I see you already had the head worked. A lot of the time and especially for the second time of having it serviced, the machine work can add up to the cost of buying a new head. You can get a new head for about $250.

I use both steel and plastic guides so don't prefer one over the other. The steel guides will keep damage from the chain to the timing cover when the chain goes bad. The chain is still the weak link and will wear out and is what usually tears up the guides along with the tensioner getting weak. Unless I get the steel guides in a rebuild kit, I don't go the extra expense for them. Overall steel is most likely the better guide but it is the chain and tensioner that goes bad. Just my thoughts on it.

On plastic guides the slapping is an indication of chain needing changed. Not sure what it sounds like on steel guides as I have never heard it on the steel guides. A good source of information on a used truck or something like that.

jimbyjimb

iTrader: (1)

Yes, I have run a head shim.

I have never heard of 22R's specifically having head gasket problems. What I have found is failed gaskets on these engines are generally due to user error on install or failure to confirm a flat head by a user trying to cut costs.

The only options I am aware of for maintaining proper head space are the shim or a new head as described above. I have used a shim on a 20R engine without issue.

If choosing between plastic and steel timing guides go with steel. Plastic becomes brittle and breaks eventually. It is also not difficult to convert later 22R engines to the older and superior dual chain.

tysen86

There's no question on the guides. Steel! Front cover already shows wear from an old plastic guide breaking.

I'm just simply looking for some conversation about head shims. Pros and cons. I've now taken .018 off the head and .010 off the block. ~.028 out of the distance between the cam and crank. Is a head shim even needed? Will a tensioner take up that much slack? Will it throw the can timing off enough to need a cam adjusting sprocket? Or will it throw it off at all? Let's talk about it fellas!

tysen86

I say a good tensioner should handle the slack. Any oil pressure problems could get real ugly, real quick! Is that a chance I want to take?

Will that much slack throw the cam out of time? Yes! Due to the fact that the cam is closer to the crank. Is it enough to need a cam adjusting sprocket? I don't THINK so. There's a gap already designed into the valves. I don't THINK that little bit of timing change will make that much difference. I'll have to look into that more.

jimbyjimb

iTrader: (1)

This is incredibly simple.

Cons: slack chain. Over the course of the engines life the chain stretches. With excess slack from the beginning the likelyhood of a jumped chain will increase in the future. Your timing will be retarded without an adjustable cam gear or timing the valves a tooth off (would not suggest this). These engines need as much advance on the valve timing as possible to make good, usable power.

Without proper head spacing your compression ratio may be raised which could potentially, but unlikely, cause fuel compatability issues.

It's your thread but I don't see what there is to talk about. Any knowledgeable engine machinist will tell you to use a shim.

Some people elect not to for the increased compression. On these small engines any performance gained by it will be insignificant unless you're building a N/A monster out of it. If you have valve relief flat top pistons and plan on a monster cam (over .450 lift) consider using the shaved head after clearancing, otherwise just use a shim. It isn't rocket science.

tysen86

See, that's what I wanted to know. The actual machinist that does my head work was out and I had to talk to some other jack ass. He said no shim. I figured he was full of it.

So, I guess we go with a shim. Easy enough. Should I shim it, and advance the cam?

jimbyjimb

iTrader: (1)

I will always suggest that you talk directly to a knowledgeable machinist, but I would shim it.

Advancing the valve timing via an LCE cam gear will be a very cost-effective performance modification. I'm not using one yet, but on other engines I've built a simple valve timing advance can entirely change an engines character. It isn't a bad way to go.

Suckers elect to spend 3-600 bucks on some stupid header and big exhaust pipe. For 90 bucks and an adjustable gear you will see a larger practical gain by advanced valve timing. Most of use are likely not revving much past 4k. I never do myself, and I drive like I'm in NASTRUCK .

I don't know if the valve timing might throw off your fuel system since its an RE. I doubt it, but if you want a gear I'd suggest talking to an LCE tech on the phone about it before getting one. They also may have more insight into the shim question than I do. They've been building R's quite a while.

tysen86

I'm going to talk to LCE about this as well, but I just got off the phone with 22RE performance and he said cam timing is the correct fix. He said he's taken .080 out of that equation and been fine as long as you time the cam. From the sounds of it, a shim is just another thing to worry about that's a pain to get to. Is that a burden I want to put on my 16 year old? Not really. Compression is not going to be that much different than stock because we bored the cylinders .020.

bswarm

Boring a cylinder raises compression, so does surfacing the block and head.

tysen86

Huh? how does making a cylinder bigger around raise compression?

millball

Piston in larger cylinder moves more air.

More air is forced into the combustion chamber= higher pressure

tysen86

It creates more displacement, yes. However, due to the fact that the piston still only moves up the cylinder the same amount as before the bore, it doesn't compress the air any more than it did before. To increase compression, you have to do one of 2 things; 1) cram the same amount of air into a smaller space or 2) cram more air into the same space. Since we bore a cylinder all the way to the top, yes, you are compressing more air. However you are compressing that air into a bigger space.

Am I not understanding something?

millball

The larger piston IS cramming more air into the same space.

Boring the cylinder does'nt make the combustion space in the head any larger.

bswarm

It's a common misconception that a bigger bore doesn't raise compression, it does.

jimbyjimb

iTrader: (1)

http://www.csgnetwork.com/compcalc.html

tysen86

Ok, so I stand corrected. Learn something every day! Good deal, more compression can't hurt. Adjust the cam correctly and I'll have more of a screamer than I thought I would

Btw,. I've done my homework on the head gasket spacer, no thanks.

Mr.Utah

I'm having the same issue. I spoke with engn builder today; there is a .0020 shim you could use, or he prefers to use the adjustable cam gear. Apparently compression and head gasket failure can be attributed to incorrect/imprecise timing which the gear can fix. I'm getting one myself.