New camshaft installation Q's

[70Hardtop]

HI, I'm building my first Mopar engine, a 340. I'm not sure about a couple of things, hope someone has more knowledge. First the specs: it is a CC (Comp cams), high lift hydraulic cam. Grind/Part # XE275HL -10. The Gross valve lift (both intake and Exh) is 0.525, Lobe Separation 110, Duration @ .06 and 0.050 = 275 /287 and 231 /237

First question is about what it says on the Specs card: It says "These specs are for the cam installed @ 106.0 degrees intake centre line"

But do I need to do anything special to make it 106 degrees? Or will it be automatically done at 106 if I just put it in with the cam sprocket timing mark lined up at TDC with the crank mark ? Or does it mean I have to buy a degree wheel and "dial it in"

SECOND question: I want to run light valve springs initially to avoid wiping a lobe on initial run-in as this is the most critical time for a cam. The valve springs recommended by CC for this cam are dual springs + a damper so they are pretty heavy. Is it ok to use worn original OEM springs (used 45 year ones from a 318) or do I need more pressure on the lobes to effectively run it in? Someone told me to pull the inner spring and damper out and run it with them initially, but I still think they might be too heavy to risk it.

Thanks

 

[TC_Cuda]

To answer your first question... you don't "need" to dial in the cam, if you just install it with the sprocket lined up properly you will be close enough.
The purpose of dialing in a cam in to be sure it is ground properly, because, there is always manufacturing tolerances, but most cams will be very close to there speck's

Don't use old springs. I would just use the outer springs that come with your new cam, that is what most builder recommend. That way your using new springs and
after break in you just install the inners and go
I hope this helps

 

[704406]

I agree with TC Cuda. I installed a comp cam in my 86 w350 4x4 with a 360. I spent the time to dial it in with my degree wheel, and it was within a 1/2 degree. There's no need to be closer than that for a street engine running thru exhaust. If the engine fires immediately and you don't let it go below 2500 rpm I wouldn't worry about the lobes. Call comp cams if you have questions, they were very helpful and answered the question I had.
Ken

 

[Adam]

Just use an additive or oil that contains zinc.
Camshaft Break-In Guide - How To Properly Break In A Flat-Tappet Cam - Car Craft Magazine

 

[70Hardtop]

Thanks for the advice and link guys. (what happened in the story in that link is what I don't want to happen to me!) . CC are a very reputable cam manufacturer so I don't doubt that the grind tolerances it will be ok, just wasn't sure about that line on their specs card: "These specs are for the cam installed @ 106.0 degrees intake centre line". Because that reads to me that the builder has to do something special rather than just line up the dots as normal. But if it is installed as per normal then it means the cam will automatically be at 106.0 degrees. That's what I wasn't sure about.

 

[704406]

My local engine shop that supplied the comp cam recommend Joe Gibbs Racing "break in" oil for the initial start up as it contains the ZDDF additive that is critical to cam lube as newer oils don't contain enough additive for flat tappet cams. I use Joe Gibbs "hot rod" oil in my stock 440 and in my 360. It's not cheap but way cheaper than a motor do over

 

[70Hardtop]

Good advice that - I must remember to buy some zinc rich oil. I doubt we would have that Joe Gibbs oil here Down Under although I will have a look. I'm sure I could get some zinc rich additive specially for this purpose though.

 

[IQ52]

Follow Comp Cams cam break in advice and always, always, time the camshaft with a positive engine stop to get TDC, a dial indicator and a degree wheel. Dot-to-dot and hope it is right is a lazy, cheap way to operate.
Jim LaRoy
LaRoy Engines

 

[TC_Cuda]

IQ52 You are correct that using a degree wheel is the right way to do it.... but many don't have the money to buy the tools to do just one job.
If there like me they just want some extra power and to be able to do it themselves

As a professional engine builder I would expect you to do the best you can. If I had you build me an engine, I know you would do it right...but
to say that WE are LAZY for not doing it with a degree wheel .... really...

 

[70Hardtop]

Jim and TC Cuda, I sort of do agree it is lazy just putting a cam in and lining up the dots and hoping for the best - IF you are building a worthwhile engine that has already had some considerable bucks spent on it and if you are expecting the best it can deliver. If someone has come that far, then it makes sense to beg, borrow or buy a degree wheel set to make sure the cam is in properly. Not doing that is a bit silly. However many people doing a budget build (not in my case) will not bother with that and hope that the factory and manufacturer settings are "good enough". Being in Australia where the common attitude of many Aussies is, "She'll be right mate" (translated to, "don't worry about a thing buddy, everything will be just fine..."), then doing it that way is all too common. I have known engine shops that consider themselves reputable and also mechanics/engine builders that value their own work highly, who would not bother with degreeing in a cam ! Crazy, but that's my city's mentality often-times.

Yes these kits are expensive for us because all this gear has to got from the States and with the postage and retail price markup, it's in the hundreds of dollars, and for just being used once, it is a cost that you really have to think about spending. In my case, I might just buy the wheel itself, say an 11" wheel and try to borrow a dial indicator. I can make a pointer and also make up a TDC indicator. Whatever the case, I want to do the best I can, otherwise its a waste of money buying that cam and maybe not knowing if it is working as it should be.

 

[IQ52]

IQ52 You are correct that using a degree wheel is the right way to do it.... but many don't have the money to buy the tools to do just one job.
If there like me they just want some extra power and to be able to do it themselves

As a professional engine builder I would expect you to do the best you can. If I had you build me an engine, I know you would do it right...but
to say that WE are LAZY for not doing it with a degree wheel .... really...

You're right. Lacking motivation.

 

[Daves69]

Or does it mean I have to buy a degree wheel and "dial it in"

If you can afford a new cam you surely can afford a degree wheel and stop I would think. Without indicating in you may leave yourself questioning why you're not seeing the performance out of your build. If you do actually happen to find it on the money when you indicate it you at least know it's there and it's not a looming question.
Do you even know if your balancer is marked at TDC?

 

[70Hardtop]

Well not really. Being in Australia, all this good gear is in the States. To buy a full kit from Ebay is $350-$450. To get one myself from the States, now with the huge increases in postage prices, is about the same or a bit less. I could buy just the wheel and make up a pointer and some device for accurately determining TDC (heads are bolted on), which is what I will probably do. But still need to get a dial indicator, maybe can pick up a second hand one or borrow one or a cheap chinese one. Believe it or not, in my city most engine builders only put the cam in and line up the dots. The good speed shops who build engines charge about $120 per hour. The engine builder who used to build only mopar engines and built some of mine never even had a degree wheel (one of the many reasons I don't use him any more). But I do want to check it yes, as the cam springs lifters etc was expensive and like you say I want to make sure it will be performing the way it was designed, otherwise I would never know. Also I have just learnt that I should also check the balancer for TDC accuracy, as I didn't know this before. The original post was written when I wasn't sure about the 106 deg centre line and if that was supposed to be when the dots are lined up. It is only my first proper engine build.

 

[Daves69]

There are links out there to investigate to possibly fabricate your own tools. Invest in a good repeatable indicator though. You can use it for other automotive checks as well.

Examples......
Homemade Degree Wheel Diagram - HomemadeTools.net

homemade piston stop - Bing images

 

[70Hardtop]

There are links out there to investigate to possibly fabricate your own tools. Invest in a good repeatable indicator though. You can use it for other automotive checks as well.

Examples......
Homemade Degree Wheel Diagram - HomemadeTools.net

homemade piston stop - Bing images

Thanks for those links Dave, they will certainly be very interesting and helpful!

 

[TC_Cuda]

You seem to have decided to get a degree wheel and that is the BEST way to do a cam install...but..

let me give you an example .. last year I built a 493 Big Block Stroker and you bet that cam was degreed ( and it was correct the first try) however..
just 3 months ago I helped a friend put a new cam in his 1976 Dodge 360 truck and we did NOT degree it and he still has a big grin on his face...
so my point is that you can get good ( even great ) results even you are a lazy butthole like me

So...whether you call me lazy or not... this is just my opinion and there is a saying about that...

opinion's are like buttholes, everyone has one and they all stink

please keep us informed on your progress

 

[70Hardtop]

You seem to have decided to get a degree wheel and that is the BEST way to do a cam install...but..

let me give you an example .. last year I built a 493 Big Block Stroker and you bet that cam was degreed ( and it was correct the first try) however..
just 3 months ago I helped a friend put a new cam in his 1976 Dodge 360 truck and we did NOT degree it and he still has a big grin on his face...
so my point is that you can get good ( even great ) results even you are a lazy butthole like me

So...whether you call me lazy or not... this is just my opinion and there is a saying about that...

opinion's are like buttholes, everyone has one and they all stink

please keep us informed on your progress

TC, I see you think that I called you lazy, well no I didn't. I read yours and Jim's posts and all I did was agree with him, conditionally, that if a person went to the trouble of building an expensive engine and all the associated effort of building it, then it would be lazy not to go to the extra effort to degree in a new cam - it would be silly not to. Maybe I didn't write it properly. Then next paragraph I said in a budget build (esp in Australia) it would be normal procedure not to really go to that trouble to degree it in. In my case, with what I have spent on my engine, and all the effort involved, I would consider it lazy (and crazy) if I did not go the extra mile and degree in the cam. In a budget build or in the case of a simple cam swap (such as you and your friend with the 360), and especially if a person did not have access to a degree wheel, then it would NOT be lazy, it would be NORMAL. I hope I have explained this satisfactorily. I think the term 'lazy' is a more emotive term than 'lacking motivation', but basically they are the same, in my book anyway !

 

[70Hardtop]

Just to add more thoughts to the above... TC, you obviously have (or have access to) a degree kit. Now, if you had built that stroker and put the engine in without checking the cam timing, and even though the engine seemed to be great, you most probably would be kicking yourself for not making the effort to get out the degree kit. But that wasn't the case. You did make the effort to do it properly. In the case of the 360 cam swap-out, it no doubt would have had heaps more performance than before even if it was a little out. But in that situation, going to the effort of degreeing the cam would most likely have not been warranted; you took a very small risk that it would be fine and it worked out well.

 

[TC_Cuda]

no I did not think that ...I see my comments were taken wrong ,and,... I apologize, for any misunderstanding I will keep my opinions to myself
and again I APOLOGIZE to any and everyone I offened

 

[TC_Cuda]

If I might add ... I sincerely look forward to reading about your progress on this project.
Please keep us informed and include pictures if you can. The best to you and yours

TC_Cuda