Timing Chain/Lifters on a 73 Eldo

[The Tassie Devil(le)]

Is a bit hard to see the wear in the pictures, but the best way to check for wear is to hold one lifter end on sideways against the side of another, and look at the resulting section.   But, from what I think I can see, one is definitely shot.

If there is light at the sides of the sideways one, then the wear is good, but if there is any light through the centre, then it is shot.

The .40 difference could be because you are measuring the Intake Lobe as against the Exhaust Lobe, and as I don't have the '73 specs in front of me I can't advise.

Bruce.

[aggie2012]

We started measuring at the back end of the cam and moved forward. The .40 was compared to the 4 before it. The mechanic I was showing it to said get rid of it. I understand it's really hard to determine if it's worn out or not from just looking at pictures. Since we're on the topic, I found a cam and lifter set on amazon. The price is about the best I've found. It is worth messing with.

http://www.amazon.com/COMP-Cams-CL94-300-5-Camshaft-Lifter/dp/B000P5GMCK/ref=au_as_r?ie=UTF8&Make=Cadillac%7C46&Model=Eldorado%7C408&Year=1973%7C1973&carId=001&n=15684181&newCar=1&s=automotive&vehicleType=automotive

[Jeff Rosansky CLC #28373]

I'm planning to do my timing chain this spring/summer.  The more I read, the more, uh fun, it sounds.

[35-709]

We started measuring at the back end of the cam and moved forward. The .40 was compared to the 4 before it. The mechanic I was showing it to said get rid of it. I understand it's really hard to determine if it's worn out or not from just looking at pictures. Since we're on the topic, I found a cam and lifter set on amazon. The price is about the best I've found. It is worth messing with.

http://www.amazon.com/COMP-Cams-CL94-300-5-Camshaft-Lifter/dp/B000P5GMCK/ref=au_as_r?ie=UTF8&Make=Cadillac%7C46&Model=Eldorado%7C408&Year=1973%7C1973&carId=001&n=15684181&newCar=1&s=automotive&vehicleType=automotive

I'd be on the phone to Marty at MTS ---  http://www.500cid.com/  --- they are Cadillac 472/500/425 experts.

[aggie2012]

I'm seriously thinking about calling in the morning, but the same questions always looms: how much more is it going to cost me?

[TJ Hopland]

I would go with MTS even if it cost a little more.  They sell good stuff and stand behind it.  Even their 'cheap' stuff is decent.

I didn't get all my stuff from them for my last build.   After one of the parts (oil pump) I did not get from them failed and caused half the motor to eat itself after 1000 miles I got all the replacement parts from MTS and its been a happy motor ever since.   They are also actively developing and bringing to market new parts for these engines.   

The oil pumps all come from the same place and many of them have a known flaw that the manufacturer apparently chooses not to address.   MTS takes those pumps and checks them all and corrects them as needed.

[The Tassie Devil(le)]

When selecting a camshaft, you can go from a fuel efficient cam, to a mild one, right up through the range to totally wild.

I got an MT3 economy cam from Marty at MTS for a '71 I was building virtually totally stock, but selected the '70 pistons as it needed a total rebuild, and it was perfect.   Then I got an MT5 for my '72, but added bigger valves, double valve springs, .040 overbore '70 pistons, and even though I haven't completed running the engine in, I am VERY pleased with the performance.   Yes, the compression is higher, but I can live with that.  8.5 to 9.5 or something close.

Using the '70 Pistons I had to have the engines balanced as the '70 pistons have a different mass than the '71 and '72 deep dish pistons.

Bruce.

[R Schroeder]

This guy has 9 original cams, from GM.
This is the correct part number for the 425 - 500 engines.

MTS is very good too. Bruce and TJ know what they are talking about.
Cheap parts don't mean your getting a good deal.
Buy the best you can, or you will be doing it over again.

http://www.ebay.com/itm/NOS-GM-Camshaft-76-77-78-79-80-81-Cadillac-365-425-500-/191078547608?pt=Vintage_Car_Truck_Parts_Accessories&fits=Make%3ACadillac&hash=item2c7d2b4098&vxp=mtr

[The Tassie Devil(le)]

Personally, without knowing the specifications of a Camshaft that is being sold on ebay, and had such a wide list of engines it fitted, there is no way of knowing if it will be actually suitable for a specific engine, year and size.

There is a vast range of compressions, cylinder head capacities, valve sizes, and timings of this vast range that even though they will physically fit inside the engines, the actual performance could be a compromise.

What might be a "power" cam in a small capacity engine, might be totally weak in a larger one, and vice versa.

Bruce.

[R Schroeder]

Bruce, my parts book says it is for all 76 to 79 Cadillac engines , 425 and 500.
I imagine it is the stock cam that came in the cars , for these engines.
That's all the info I can give out.
Roy

[R Schroeder]

He does have a type -o on the 368 engine. He calls it a 365.
But ,this is the listing that is in my parts book. My book only runs from 76 to 81, so I don't know about the other info in his ad.
But, I took the picture of my book.
To each there own I guess.
Roy

[The Tassie Devil(le)]

G'day Roy,

I understand, but the spiel of the seller indicates that it will fit from 1968 to 1984.   That is too vast a ranve as there were so many differing compression ratios, valve and combustion chamber sizes, as well as piston configurations for it to be compatible with a 1973, unless one has trhe full specifications for all possible stock camshafts to compare.

Bruce.

[R Schroeder]

Bruce, what he has in his ad may be wrong for some of his listing. But, the cam listed is correct for the 78 , with a 425.
It is also correct for the other ones I have in that picture.
I don't have a book for 73, so I could not say if it is right or not.

78 - its good.   Pt number 1486583
Roy

[Glen]

From the 1974 MPB.  Interesting in that the cam was used in the 68 â€" 70 and came back for the 74.  A different cam was used 71 â€" 73. 

[TJ Hopland]

71-73 was the 'old' high compression head with massive dished pistons to lower compression.  74 was the 'new' head.  So my guess is they needed a different cam to deal with that head piston combination and after they came up with the new head they were able to go back to their original cam design?  I think I remember reading that the 73 cam had a fairly long overlap, maybe that was the difference.   

[aggie2012]

Well guys, I made a call to Marty at MTS. I told him my situation and he's sending me a cam that he pulled out of a low mileage engine. Now I'm just waiting for FedEx to show up with it.

Another question I have is I ordered a Perfect Circle timing set from RockAuto. I read a few more threads and I keep seeing that a Cloyes timing set is the only one to use. Will the Perfect Circle set do the job, or do I need to reconsider?

[TJ Hopland]

Dunno.  Perfect Circle seems to be related to Clevite and Clevite used to be a decent name. Not sure where perfect circle falls into the line up, don't know if that is a store brand they make or what.  Its not mentioned on their site.  They now appear to be part of Mahle what ever that is.  Victor Rienz appears to be part of their catalog.  I have not bought any of their stuff recently that I know of.     

[35-709]

That's another question you could ask Marty, but Perfect Circle has always been a good name.  Important thing is you are getting rid of the plastic tipped gear.