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Topic Review (Newest First)
12-04-2012 01:41 AM
cobalt327
Quote:
Originally Posted by Hoyt71 View Post
Thanks for all of the replies. The engine had to come out anyway to replace a bad ring gear and clutch.

I removed the cam and I believe it to be a stock type. It isn't a ford, but the difference between the base circle subtracted from the lobe multiplied by 1.73 comes to .432 to .437 lift. The tail of the cam has no manufacturer but has the number 940355 in one spot and 580 in another. It also has a casting of 1208 on the side.

Just curious at this point if I am correct that he probably has a stock cam.

I hear everybody on the complete tune up and will get there when it goes back in. I haven't worked on this engine before and you have to understand that my dad and I do not see eye to eye on tune up and maintenance, so that may very well be all it needs.

I just need to know, if at all possible, what he for sure has so I can put his mind at ease. Then I'll get it lined out. I have tried all over Google with no luck. I'm hoping someone will recognize the part number and can point me in the right direction. Thanks.
That's a stock cam in all likelihood.

More: M-Block 351M/400 Parts Reference
12-03-2012 01:48 PM
techinspector1 Most domestic camshaft cores are produced by CWC Textron, Muskegon, Michigan. The numbers you're seeing are probably theirs.
12-03-2012 01:25 PM
Hoyt71 Thanks for all of the replies. The engine had to come out anyway to replace a bad ring gear and clutch.

I removed the cam and I believe it to be a stock type. It isn't a ford, but the difference between the base circle subtracted from the lobe multiplied by 1.73 comes to .432 to .437 lift. The tail of the cam has no manufacturer but has the number 940355 in one spot and 580 in another. It also has a casting of 1208 on the side.

Just curious at this point if I am correct that he probably has a stock cam.

I hear everybody on the complete tune up and will get there when it goes back in. I haven't worked on this engine before and you have to understand that my dad and I do not see eye to eye on tune up and maintenance, so that may very well be all it needs.

I just need to know, if at all possible, what he for sure has so I can put his mind at ease. Then I'll get it lined out. I have tried all over Google with no luck. I'm hoping someone will recognize the part number and can point me in the right direction. Thanks.
12-02-2012 01:33 PM
techinspector1 All aftermarket cams are stamped on the rear face. I think the reason they don't stamp them on the front of the cam is that the cam sprocket has to fit flush and if they stamped the cam on the front, the numbers and letters would stand up off the surface and interfere with the sprocket sitting flush. I don't know this for sure, but it's the only thing that makes sense to me. Stock cams will not be stamped on the rear face.

In the 70's, Ford used some crank sprockets that retarded the camshaft by up to 8 degrees and since you have no idea what sprocket is on the crank, you have no option but to pull the cam and identify it. If you want to keep it, put it back in with the exact lifters in the exact same position and degree the camshaft.
12-02-2012 11:19 AM
OneMoreTime If it needs a new timing chain go for that..what I have had success with is to advance the timing to 9/10 degrees at idle..the carb may be an issue as it may be fat on the idle mixture which will cause some loading issues..try the simple stuff first..

Sam
12-02-2012 11:02 AM
hcompton No there is no good way to find out what kind of cam is in the engine.

You cannget out the graph papper and degree wheel with dail indicator and make a map of the cam but it will still be pretty useless.

Lift and duration may help narrow down but factories made so many cams its next to impossible to say they never used one. Could be a car engine with big cam or tall gear heavy truck engine. In 78 a lot fo things were tried that didnt always work.

I would start by working the issues. Work the problem is a common statement at nasa cause of compexity trying to guess the cause is to hard you can only work the issues found back to a resolution.

Its in and it works dont remove the lifters or change the cam. Unless ypu are sure its the problem. With todays issues with cams wiping during start up i would take the safe road here with dad pickup.

Hope this helps.
12-02-2012 10:52 AM
hcompton What type of carb and by loading up what do you mean exactly.

If it needs a timing chain i would bet that is part of the issue. If the cam was replace they would have put in the normal timing chain as well. Are you sure its retarted or does it just call for one.

I would get a good double roller stright up chain and be done cam is probably not the issue. I would look at the plugs first if it doesnt have any bump at idle i would assume its not a bigger cam. Small enough cam to not bump will pull hard right out the gate. Unless its poorly designed. Sometimes the ends are stamped so you can read the numbers without removing.

I would look at the carb and the plugs for loading issues. Maybe little more timing at idle my help smooth it over. Hotter plugs can help prevent fouling form carbon but from oil you got ring issues.
12-02-2012 10:43 AM
vinniekq2 tak e the cam out? measure it,get it measured,check for part number.
3 way cam sprocket,offset keyways,,,,
12-02-2012 08:22 AM
Hoyt71 Any suggestions to figure that out? I was under the impression the manufacturer and number would be on the nose and they are not. I do not have access to a degree wheel to find the duration so I maybe just stuck.

If it were all me I would just change it so I knew what I had. I didn't know if a stock replacement or lower end double roller would have the cam retard built in or if they would be an honest straight up.
12-02-2012 12:51 AM
vinniekq2 advancing the cam cam bring the power curve down .You should know what you have before advancing or retarting
12-01-2012 11:14 PM
Hoyt71
351M Cam Questions

I am working on an engine for my dad and need some information. The engine is a 351/400 (not sure which) from a 78 Ford truck. He is having a hard time with it loading up at idle in the pasture and thinks the previous owner might have put a cam that was on the big side in it. We have the engine out to replace the clutch and some gaskets. Is there a way to determine what the cam is without completely disassembling the motor? I pulled the timing cover and cam gear but there are no numbers or manufacturer on the front of the cam.

On the same subject, is it true that a bigger than stock cam can't be used without changing valve springs and retainers? My only thought was to measure the valve lift at the valve with a pair of calipers and see if it is bigger than stock.

If it has a bigger cam, he wants to go back to a smooth idle cam. To me it doesn't sound that big but it might have a slight lope to it.

In doing my research on this engine it is my understanding that the timing set has the cam retarded from the factory. Is this worth trying to defeat? It needs a timing set anyway. If defeating the cam retard is a good thing, does any parts store timing set do this or only certain ones? I know a double roller for a SBC from Cloyes can be as cheap as $25 to well over $100 and I'm not sure why.

Thanks for any help and education you can give me. I did a search but couldn't find these things covered.

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