hi..i am starting the long slow process of restoring my 64 coupe..i am starting on the engine..my question is what type of cam will be correct for this 375hp fi 327....thanks for this great site...
kent #43669
kent #43669
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Re: 64 engine cam
You can still buy the original "30-30" cam, but I recommend the LT-1 cam. Both are available from GMPP, Federal Mogul, and some aftermarket cam vendors.
There is lot's of discussion on this subject in the archives.
If you rebuild the engine, you should replace the connecting rods as the originals are weak and have wreaked many 870 blocks when they broke. I recommend Crower Sportsmans. All other parts OE or OE equivalent.
Duke -
Re: 64 engine cam
Kent,
The original cam that was installed in your 64 375 HP engine when new was a GM 3849346. It's an excellent cam and it's still available today from several sources/vendors, including Crane Cams in Florida. (my personal choice) Give them the GM part number and they will supply you with an exact duplicate of the original cam. Good luck with your restoration,
MichaelComment
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Re: 64 engine cam
I might also add that the 3849346 (30-30) cam was discontinued from service parts circa 1970 and replaced with the 3972178 (LT-1) cam.
Similarly, the early 3733431 (300 HP ) cam for medium performance SBs was discontinued from serice circa 1967 and replaced with the 3696929.
Why? Because both cams were better than their predecessors for the intended applications. In particular, the LT-1 cam will make more low end torque with no meaningful sacrifice of top end power.
DukeComment
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Re: 64 engine cam
Just bought a new replacement 30-30 myself. CS 118 R Speed Pro. Keep your original cam. They sound better and run better than the LT-1 if you keep the thing geared fairly low. And, you'll still be "original".Comment
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Look Up RESTORE.....
Well, Duke, I wanted to make sure that I properly understood Kent's question and since I wasn't an english major, I decided to look up a few of the words in his post. One that especially interested me was his use of the word "restore", which seems to be somewhat misunderstood by many people. Indeed, the word exists and there was a description of it's basic meaning. It went something like.. " To Bring Back To, Or Put Into A Former State".
Another word that Kent mentioned was "correct", which, when used in the same sentence,would accent the word "restore". Webster describes it as "To Make Or Set Right".
I'm surprised that an outfit as big as Websters Dictionary has never heard of the 178 cam and makes absolutely no mention of it at all in their latest edition. I will try to contact someone there and attempt to correct this error. It should state; "To Bring Back To, Or Put Into A Different State".
Regards,
MichaelComment
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Re: Look Up RESTORE.....
So I guess a 283 or early 327 medium performance engine that is assembled with a 929 cam is NOT RESTORED!
I challenge any judge to be able to tell the difference in engine characteristics between the LT-1 and 30-30 cam or the 431 and 929 cams during an ops check or PV.
I can even make the LT-1 cam sound like the L-79 cam, but I haven't yet figured out how to disguise a L-79 cam as a 300 HP cam, in fact, it CAN'T be done.
DukeComment
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Re: Look Up RESTORE.....
So, if there's no difference, why do you insist everyone scrap their correct original 346 cam for the 178? I don't understand your motives at all. If there was no current source for the correct 346, I might understand but if either cam is a phone call away, recommending a totally incorrect non original replacement makes absolutely no sense. And I don't buy that story about the LT1 cam being better, not to mention the fact that isn't the point of all this. Better or worse, it's still stupid to recommend that anyone intentionally install an incorrect part in any car that is being RESTORED when the correct one is available.
You can try to dazzle everyone with your cam numbers and dyno sheets but the proof is in the results, not the numbers. I've installed that LT1 cam in several engines over the years so I know first hand if it works. I'll tell ya about another guy that would add his opinion, if he were still alive today. Of all the hundreds of GM cams that Yunick had in that shop, guess how many were 178 LT1's. Yep, ZERO! He laughed at that cam. He was the one who first called it a "smog cam", not me. Ask Ralph johnson about the 178 and he just chuckles. He and Yunick have a lot more cam development time than you and I and a few more GM engineers put together.Comment
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ralph johnson
michael, is ralph still alive and well? the last time i saw and talked with him,5/6 years ago,he was at crane cams.Comment
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Re: ralph johnson
Spent about an hour on the phone with Ralph about a year ago and he was doing well. Still lived on the east coast near Daytona. Hopefully, we'll get over to see him soon.Comment
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Mike, Read This And Get Back To Me!
All:
Here is an excerpt of a letter that I wrote to one of our contributors some time ago. Please read it CAREFULLY, especially the parts about horsepower, torque, SHP engines, and Chevrolet's "easy horsepower" era.
Joe
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6/23/05
Dear ???????:
Would you please stop telling people to install LT1 camshafts in their 1963-1967 Corvettes. It is insulting, and a sacrelidge.
Now, obviously, you are an engineer, and have all of the formulas and technical information to prove it, but, you are not reaching the right audience.
Now, if this was 1970, then I could see your point, ONLY if you were talking to people who were looking to race their Corvettes before the era of bracket racing. At that time, racers were looking for the edge, any edge, to drop their ET by a hundreth of a second. Even so, I am not very sure that the LT1 camshaft would lower ET in the 1/4 mile, because there has never been a comparison test done with identically configured 327 vs.350 cubic inch engines with LT1 vs. Duntov/30-30 camshafts installed.
As you know, the 30-30 equipped 327 was rated at 365 SAE gross horsepower, which yields 1.12 HP/CI. The 1970 LT1 equipped 350 was rated at 370 SAE gross horsepower, which yields 1.06 HP/CI. The 1964/65 L76 yielded 350 ft-lbs of torque, and the 1970 LT1 equipped 350 yielded 370 ft-lbs which is 1.07 versus 1.05 ft-lbs/cu in. I don't have the peak torque ratings @ RPM available, but based on the above, both the torque and horsepower differences are negligable, and actually favor the more radical 30-30 cammed 327 engine. Now, you know, as well as I, that torque is directly proportional to cubic inches, therefore, the 1964-65 L76 engines were remarkable in terms of their specific power output, and peak torque output.
Between 1965 and 1970, Chevrolet was having a happy party, and the bean counters were counting lots of revenue with the newly minted "mystery motor/MKIV" big block. There were no SHP smallblock Corvettes, with solid lifters, from 1966 through 1969. There was only the mild mannered "SHP in name only" L79 engine. Finally, in 1970, after a hiatus of five years, Chevrolet, in light of the looming EPA emission standards, finally rediscovered their smallblock engines and decided to market the LT1 as the ultimate Chevy "engine of the future". Overly hyped, IMHO. Why did they do this? Because THEY KNEW THAT THE ERA OF EASY HORSEPOWER AND TORQUE WAS OVER.
And so, getting back to "your audience", whom you have razzled and dazzled with your lenghthy technical dissertations, and erstwhile good advice, I urge you to keep a couple things in mind. First and foremost, many of the good people that look to the NCRS Tech Board for advice are not racers, and so will not notice any marginal difference in performance (nee, whether empirically tried or not), so do not offer "unproven enhancements" unless a specific application is delineated. And second,.......................
Best regards,
Joe CiaravinoComment
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What can I say?
I remember when you wrote it the first time. I agreed with you then and I agree with you now. I also agree that some of these people making this switch never new what the old cams (30-30) ran like. They don't know whether they'd like the way they ran or not.
Aside from the sound of the 30-30, the best thing about it is when it gets up on the pipe (about 4000) and cuts loose.
I don't see the 302 Z-28 (same cam) guys putting LT-1 cams in their engines. Lord knows they are a little short on the low end.
It all boils down to this, with me. If you're restoring a car or trying to make it period correct, make it run, sound and look like it's supposed to. Not like Harry Hot Rod has been working on it.Comment
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Re: Look Up RESTORE.....
I didn't say there is "no difference" There is! The LT-1 cam has broader torque bandwidth, but has about the same subjective idle characteristics as the 30-30 cam. As far as Yunick and company are concerned, they never paid any attention to the torque curve below 3500 RPM.
I have to laugh at you guys getting you panties wadded up over my LT-1 cam recommendation (That's recommend, not "insist").
Where are you all when guys paint their cars with BC/CC or enamel, whether or not they try to "disguise" the enamel as lacquer, which is not easy to do and is usually easily detectable.
I'll keep on making my recommendations with data to back them up, and you guys can do whatever...
DukeComment
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Re: What can I say?
Mike:
I knew that you would agree, and I'm sure that more than a few others here will, too. Actually the post was sent to Mike H, because he was first to take issue, above.
I never posted that letter here, back in June, but sent it directly. I did that out of respect for the "offender", because he/she is such a rich contributor to this forum. But on this issue, I strongly disagree with him/her. I reluctantly decided to finally post it here so that our entire readership could decide for themselves, based on the opposite viewpoint. The major point that I hope to make here is the SPECIFIC power output. The 30-30 cam, in fact, excells in both torque and horsepower output when you factor in engine displacement.
JoeComment
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Re: Look Up RESTORE.....
wow...thanks to each and every one of you for responding to my question..with all the input posted i will think on this one...LT1 VS 3030..thanks again,,kentComment
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