TylerJY Posted February 22, 2013 Share Posted February 22, 2013 In preperation for the '99 swap, I am rebuilding my 4.0, I am starting with the bare block from a '93 4.0 and using everything else (head, water pump, oil pump etc.) from the '99. I have a few ideas of the components I am wanting to put into this motor so if you guys could take a look and shoot me an opinion that'd be great :) http://www.compperformancegroupstores.com/store/merchant.mvc?Store_Code=CC&Screen=PROD&Product_Code=CL68-232-4 http://www.northernautoparts.com/ProductModelDetail.cfm?ProductModelId=25149 http://www.compperformancegroupstores.com/store/merchant.mvc?Screen=PROD&Store_Code=CC&Product_Code=926-12&Category_Code=A6Valve http://www.northernautoparts.com/ProductModelDetail.cfm?InventoryId=97353 I'm not sure if cam bearings come installed on the new camshaft, and I still need to locate some freeze plugs, but I think everything else I need is located in these 3 links, I am mainly interested in hearing what you all have to say about the Comp Cam and if that is a good replacement. Also, is it worth it to have the head ported and polished? How much does that usually cost? Link to comment Share on other sites More sharing options...
Biotex Posted February 22, 2013 Share Posted February 22, 2013 Head porting and especially polishing is costly. Comes more into play in high rpm engines, so IMO a complete waste of money. Port matching is worthwile, but i'd stay away from polishing. You can actually lose efficiency from too much polishing. I haven't looked at the links you posted yet, but I will... Edit: Cam bearing get installed into the block, they come with a complete gasket set. Link to comment Share on other sites More sharing options...
TylerJY Posted February 22, 2013 Author Share Posted February 22, 2013 Thank you for the reply, I will have to get a quote for port matching the head and intake. Link to comment Share on other sites More sharing options...
nitroxsteve Posted February 22, 2013 Share Posted February 22, 2013 The cam bearings are pushed into the block so you will need to have them installed when you have the block machined. Link to comment Share on other sites More sharing options...
nitroxsteve Posted February 22, 2013 Share Posted February 22, 2013 The cam bearings are pushed into the block so you will need to have them installed when you have the block machined. Also I usually have the machine shop istall the freeze plugs and they supply them. and don't order anything untill the machine work is finnished and you know what is needed. Link to comment Share on other sites More sharing options...
Biotex Posted February 22, 2013 Share Posted February 22, 2013 If it were me, I wouldn't use springs with too much pressure. It's a fine line what is too much, but be advised that you will want to break the cam in without the inner springs installed. This means puttingthem back in after break-in, more to think about... Higher valve spring pressure help to keep the valves from "floating" at higher rpms. Again, you 4.0l just isn't the motor to be turning the kind of rpm's that the fancy aftermarket racing products are trying to goad you into believing that you have to have them. Higher valve spring pressures wear out the seats faster, and on a flat tappet cam, you have a greater chance of wiping out a lobe. If it were me, I wouldn't run those unless the cam manufacterer insists you have to. IIRC the 05 and 06 engines have higher spring pressures than earlier versions. Might want to research what that pressure is, and duplicate it. Link to comment Share on other sites More sharing options...
TylerJY Posted February 22, 2013 Author Share Posted February 22, 2013 Are you speaking of the spring pressure on the ones I linked? Comp Cams does state that you can't use stock springs with that camshaft. Link to comment Share on other sites More sharing options...
Biotex Posted February 23, 2013 Share Posted February 23, 2013 Yes, aren't the ones you linked to a higher spring pressure than stock? they appear to have an inner spring. That inner spring is the one I referred to that it is best to remove on cam break in. High spring pressures on flat tappet cams don't mix well. In the old days zinc and phosphates were added to oil to apply a harder surface coating to help reduce lobe wear. That ZDDP additive is getting harder and harder to come by unless you run expensive racing oils like Joe Gibbs. It is my opinion that you don't really need much higher than stock spring rates on these relatively low rpm engines. A good 3 angle valve job will suffice. Since that cam requires per the manufacturer a stiffer spring, I would call them and talk in person to a tech and ask him if you run the risk of premature wear. That cam may be one that is intended to just run a few races and then the engine would be rebuilt IDK. I didn't really look at the lift and duration specs on the cam you linked. If a cam has to have higher pressure springs, then perhaps, just saying perhaps, that cam is not right for your 4.0L. I'd talk to a knowledgeable engine builder in your area, and ask his opinion. I see a lot of guys buy way too much cam for their needs, and it is expensive to do it twice. Link to comment Share on other sites More sharing options...
Biotex Posted February 23, 2013 Share Posted February 23, 2013 Tyler, I finally got the time to study those springs recommended. That cam seems like a decent 4x4 cam, as in it is not too radical. The picture of the springs shows them with an inner spring, but it states that they are single outer spring, so that is good. Means it is easier for break in... The spring rate is 415# though. Mopar HP springs are something like 270#. Do some research, but in my opinion Competion Cams springs are too much for todays reduced ZPPD oils. Link to comment Share on other sites More sharing options...
mountainman Posted February 23, 2013 Share Posted February 23, 2013 If it were me, I wouldn't use springs with too much pressure. It's a fine line what is too much, but be advised that you will want to break the cam in without the inner springs installed. This means puttingthem back in after break-in, more to think about... Higher valve spring pressure help to keep the valves from "floating" at higher rpms. Again, you 4.0l just isn't the motor to be turning the kind of rpm's that the fancy aftermarket racing products are trying to goad you into believing that you have to have them. Higher valve spring pressures wear out the seats faster, and on a flat tappet cam, you have a greater chance of wiping out a lobe. If it were me, I wouldn't run those unless the cam manufacterer insists you have to. IIRC the 05 and 06 engines have higher spring pressures than earlier versions. Might want to research what that pressure is, and duplicate it. Just to help you out, higher valve spring pressure doesnt hurt anything. Only valve spring pressure thats too low will cause excess wear. Because the valves float and dance at varying rpm and it damages the seats quick. Higher pressure allows the valve to track the cam better at all rpm and prevents float. Float being what destroys the seats cause the valve smacks the seat freely cause it wasnt tracking the cam properly. But you are right if you run super spring pressure you do want to pull the inners to break in the cam. from there the only thing that may suffer from too much spring pressure would be a broken rocker, or a mushroomed pushrod if you have weak or aluminum pushers coupled with monster springs. Link to comment Share on other sites More sharing options...
mountainman Posted February 23, 2013 Share Posted February 23, 2013 Add this to your oil and never worry again. http://www.zddplus.com/ Its what i run in all my flat tappet builds. No issues at all. :) Link to comment Share on other sites More sharing options...
Biotex Posted February 23, 2013 Share Posted February 23, 2013 Yes, a good choice for added protection. Just be carefull that you don't add too much, as it is just as bad as too little I'v read. Link to comment Share on other sites More sharing options...
TylerJY Posted February 23, 2013 Author Share Posted February 23, 2013 I was planning to run an engine oil with ZDDP added, I believe the Rotella oil from Walmart has a decent amount? I am also planning on running the Comp Cam break-in oil while i break the engine in. Edit: After doing some research it appears I'll have to have the head machined to use the CC valve springs because the installed height is different, so that makes the MP springs more appealing as they have the same installed height as stock. Link to comment Share on other sites More sharing options...
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