4.0 Cam Emissions

[C5GY63E]

Hey folks, I am the rookie on the list. Just found the list today and have been reading many interesting "threads". I was out looking for 4.0 info because I am working on my 92 Explorer. It has 323,000 miles on it and was running like a top until about 1 month ago. It developed a ticking noise when it was cold but went away as the engine warmed up. Over the last few weeks it has become worse and lasting longer so I started to investigate. After talking to several shops and my local Ford dealer they all had similar thoughts, something in the valvetrain. This is what I suspected but thought maybe some words of wisdom would come from folks who work on them daily. Oh well, so much for that hope. Anyway, last Saturday I pulled the intake with hopes it may be a lifter. Upon this removal I find out the lifters only come out after pulling the heads, so off they come also. I start thinking "are we having fun yet?".

Now this truck has run pefectly since the day I bought it new in early 93. It has had Mobil 1 5W30 every 5K miles and has never used more than a 1/2 quart between changes so I figured all was fine. Well I thought while I had these heads off I might as well have a valve job done just for some insurance, assuming the valve seals certainly are not going to last a lifetime. Much to my surprise I get a call the next day from the machine shop that both heads are cracked (now I know where that little bit of water was going every month or two).

Ok we now have a new pair of heads ready to go back on but I thought while we are this deep, why not look at cam possibilities? After doing some checking, about all I see are a couple profiles by Competition Cams. An RV style cam and a more radical version for a more heavily modified truck (mine has a shift kit in the trans (automatic) and a K&N filter so I am about as stock as it gets).

After all this background that I am sure most of you could care less about, my question is, does anyone on here know how emissions legal this cam is? I called Comp and they said it will not pass in California but has anyone else installed one and failed/passed anywhere else in the country?? Also wanted to know if anyone felt the upgrade was worth the price tag which looks to be about $230 from Summit Racing. Let me know if you are aware of a better price elsewhere.

Thanks in advance for any help.

 

[SteveVB]

shouldnt be a problem

I have the 410 comp cam(the RV cam) in my navajo and with a larger TB, a bigger MAF and headers and K&N filter I smogged fine. Here in MD we have a road test or dyno test where they stick the truck on a dyno and drive it over a road course on the computer. PAssed with flying colors, most of my values were half of what was allowed. So I dount you will have any problems with a test.
230 sounds about right- I think I paid closer to 250 though!

Cam Craft would be another source to check. www.camcraft.com

If you havent already do a search for the cam install- you will need to check pushrod length and have some rods made up. Also check the rocker arms carefully- they are frequently very very worn at the tips and push rod cups- causing lots of noise and slop in the valve train.
www.stevensparts.com had decent take offs when I checked. lifters, oil pumps, rocker assemblies and decent prices.

Was it worth it- yes. Good power from 2000-2500 and up and no loss in power in the lower rpms. If you have the engine out or are rebuilding I would do it again no question, the cost is going to be a bit more than just the cam though - the pushrods are needed. The other things you need for the cam you would need to replace in a rebuild anyway so the incremental cost is just the cam and the rods - a little extra time to set it up correctly, so it is a must do for any one who has the engine apart IMO.
Good luck

 

[C5GY63E]

Steve, thanks for the reply but now I have another question. You say I will need different pushrods. Why would I need them, does the 410 cam have a different base circle than the stock one? Would seem very unusual for that to be the case? (Be aware I am used to building small block V8 Ford engines and changing the pushrods because of a cam change is highly unusual). Sorry, but just more confusion since I am a rookie at the 4.0.

Thanks again,
Jerry

 

[SteveVB]

Yep, combined with the non adjustable rockers and the effects of any milling on the heads plus tolerances = new pushrods. Its not that bad, smith bros can make some up and ship them out in less than a week, I think I paid 80 dollars or so for CM tubular rods- stock are solids. The measuring is the trick - but nothing if you have built engines before and checked any type of rocker arm geometry. Its been a few years since I set it up, but I dont remember any complications - just measure, call in the order, wait, install, done.

Jerry check the search of the site and search for comp cams, or 410 or pushrods you will get some more "color" on the subject.

 

[C5GY63E]

Steve, do you have a way to contact the "Smith Bros" you menioned? I am installing brand new head castings so no milling is being done and also brand new Ford rockers. I would think that this would take me back to factory specs on everything so if the cam base circle is the same it would certainly seem logical that stock length pushrods would be used. Onew trick we use on the Ford FE series motors with non adustable rockers is to put a shim under the rocker arm shaft stands to get your proper preload. Wonder if anyone has done that? Thanks

 

[SteveVB]

www.pushrods.net


Shimming might be a problem since the oiling passage runs up through one of the center stands.

You may be ok but I would definately check the lifter preload after the heads are on and the lifters are in- it wont take much time, and you will be sure its done right before you button it all back up.

Tip: If you dont have the improved intake and valve cover gaskets from Ford- get them . Well worth the increased cost over the fiber aftermarket gaskets. www.fordpartsnetwork.com is a great source, priced right, and reliable