64 SHP Cam and lifter identification

[Doug L.]

I'm not having much luck finding information in the archives to help answer my questions about how to determine if the cam and lifter are original and correct for my 1964 L84 375 HP fuel injected engine. My engine is completely apart. When I removed the valve lifters my initial impressios was that they were hydraulic lifters. There are oil holes in the sides. However I am unable to compress the internal part as I would expect to if they are hydraulic lifters. Can anyone post a photo of a correct solid lifter or describe how one can determine which lifter it is?

Is there any way to positively identify the cam as being the correct "30-30" cam? The car was not running when I bought it so no clues there. There are no numbers on either end journal. I do find casting data between lobes. It says "F8" ; "GM18"; "18"; and 2182". Are these clues?

I'd hate to put the engine back together and find that I don;t have the correct cam and/or lifters.

Thanks-Doug

[Duke W.]

Re: 64 SHP Cam and lifter identification

It's a GM LT-1 cam - 3972182 finished camshaft part number, 3972178 cam and pin assembly, which is what was sold over the counter.

The lifters are probably the piddle valve type, which are two piece and look like hydraulics. They were only used on big blocks as OE and allow more overhead oil flow, but the early SB "edge orifice" lifters are not longer available, so the piddle valve type is the only game in town.

Assuming you are going to replace the cam, go with the same LT-1 design - Speed Pro CS1145R - and the companion mechanical lifters will be of the same type you removed. No one will ever know that it doesn't have the "correct" cam. I know of at least one 375 HP L-84 with a LT-1 cam that has achieved the Duntov Award, and the PV judge never had any reason to question that the engine was anything other than original in it's overall behavior, including idle behavior.

If you marked what lobe the lifters mate to and the cam is not worn more than a couple of thou, there's no reason not to use it again.

The LT-1 cam replaced the 30-30 cam for service parts circa 1970, and is a much better design for a road engine. The 30-30 is way too big a low end torque killer to be a decent road engine cam.

I recommend the LT-1 design to replace both the Duntov and 30-30 for all 327 mechanical lifter engine restorations.

If you want to maximize top end power, massage the heads. With massaged heads and proper set up of the 3911068 valve springs (Sealed Power VS677) the engine will make useable power to about 7250, which is where the first signs of valve float begin to show up, while easily pulling from less than 1000 revs in top gear.

If you do a 340, 350, or 365 HP engine to this "327 LT-1" configuration (search archives for more details) it will make close to 290 @ 6500 SAE corrected RWHP with 80 percent of peak torque at 2000, and Fuel Injection in place of the carburetor should push it to 300 or more with about equal low end torque. As built by Flint these engines are in the range of 220-240 SAE corrected RWHP.

Duke

[Joe L.]

Re: 64 SHP Cam and lifter identification

I'm not having much luck finding information in the archives to help answer my questions about how to determine if the cam and lifter are original and correct for my 1964 L84 375 HP fuel injected engine. My engine is completely apart. When I removed the valve lifters my initial impressios was that they were hydraulic lifters. There are oil holes in the sides. However I am unable to compress the internal part as I would expect to if they are hydraulic lifters. Can anyone post a photo of a correct solid lifter or describe how one can determine which lifter it is?

Is there any way to positively identify the cam as being the correct "30-30" cam? The car was not running when I bought it so no clues there. There are no numbers on either end journal. I do find casting data between lobes. It says "F8" ; "GM18"; "18"; and 2182". Are these clues?

I'd hate to put the engine back together and find that I don;t have the correct cam and/or lifters.

Thanks-Doug

Doug------


The "GM18" embossment identifies the camshaft as a GM-sourced piece. The "2182" identifies it as GM camshaft assembly part number 3972178. This camshaft replaced the original GM #3849346 for SERVICE in 1970. The 3972178 is the camshaft used in PRODUCTION for 1970-72 LT-1's and became the SERVICE camshaft for 1964-65 L-76 and L-84 in 1970.

For street applications, I think the 3972178 is a better camshaft. Chevrolet did too and that's why they early-on discontinued the 3849346 in favor of the 3972178. The 3972178 also uses tighter valve lash specs than the 0.030/0.030 used for the original cam. Some folks still prefer the original. Of course, this is no longer available from GM as it was discontinued in 1970. However, you can get this camshaft in reproduction. Someone must have replaced your camshaft with a GM replacement sometime after 1970.

Mechanical valve lifters have a hole in the side just like hydraulic lifters. If they didn't, you'd never get any oil to the valve train. The original lifters for your engine were of the EDGE ORIFICE type. This means that the hole was located in the upper portion of the lifter on the shiny, machined surface, usually right at the interface of the machined surface and the reduced diameter center portion of the lifter. These same type lifters were used for most small blocks with mechanical lifters except 1969 302 cid Z-28's. They were GM discontinued quite some time ago and are extremely difficult or impossible to find in the aftermarket.

If your lifters have the hole in the reduced diameter, center portion of the lifters, then they are PIDDLE VALVE type lifters, either GM or aftermarket. These are the most common type of mechanical lifter and were used on all mechanical lifter big block engines. They deliver more oil to the valve train.

[Bill M.]

Re: 64 SHP Cam and lifter identification

Is there any way to positively identify the cam as being the correct "30-30" cam? Doug

If you decide to look for the factory 30-30, look for the number 3849347 cast into the shaft just behind the next-to-last cam journal.

[Bill M.]

Re: 64 SHP Cam and lifter identification

Can anyone post a photo of a correct solid lifter or describe how one can determine which lifter it is?

Thanks-Doug

Doug:

I found these drawings in the '65 Supplements:

[James B.]

Re: 64 SHP Cam and lifter identification

Doug, I have a '64 fuelie also. Jerry Bramlett recently rebuilt my fuel unit. The engine in my car was rebuilt in 1984, long before I bought it and I was unsure of the cam. Did some measurements and research and ultimately found it is an LT-1 cam (and original, high compression pistons). As said above, Jerry recommended I keep the LT-1 cam as it is a better match to the fuel injection than the 30-30. I did a static set on valve lash to the recommended .024 intake and .030 exhaust. I am very happy with the combination- I've got good vacuum, idle lope about same as 30-30 and the combination is very driveable. With a good fuel unit (& good racing gas) these things are fun to drive!

[Doug L.]

Re: 64 SHP Cam and lifter identification

Thanks for all of your help guys. I will take another look at the lifters tomorrow. My engine has the original pistons and rods but one rod is bent. I planned on replacing the rods anyway after reading recommendations on the TDB. The bent rod made that plan mandatory.

The cylinders had a significant ridge and after 60 thousands was taken off there was still some material to be removed. The machinist recommended sleeving the cylinders as the only practical way to use the block and we are doing that. Installing sleeves will allow us to take the bore back to original which means I can use the original pistons, assuming we don't find any problems with them.

Then the lifters got me worried, thinking they were hydraluics which led me to fear that the cam had been replaced with an incorrect unit. Now I understand that the cam was replaced with the LT1 cam but it is a good grind for this engine. There doesn't seem to be much wear on the cam so I plan to reuse it. I neglected to mark the lifter positions when they came out so I will have to replace them.

Making progress!
Doug

[Doug L.]

Re: 64 SHP Cam and lifter identification

Thanks for all of your help guys. I will take another look at the lifters tomorrow. My engine has the original pistons and rods but one rod is bent. I planned on replacing the rods anyway after reading recommendations on the TDB. The bent rod made that plan mandatory.

The cylinders had a significant ridge and after 60 thousands was taken off there was still some material to be removed. The machinist recommended sleeving the cylinders as the only practical way to use the block and we are doing that. Installing sleeves will allow us to take the bore back to original which means I can use the original pistons, assuming we don't find any problems with them.

Then the lifters got me worried, thinking they were hydraluics which led me to fear that the cam had been replaced with an incorrect unit. Now I understand that the cam was replaced with the LT1 cam but it is a good grind for this engine. There doesn't seem to be much wear on the cam so I plan to reuse it. I neglected to mark the lifter positions when they came out so I will have to replace them.

Making progress!
Doug

[Tom B.]

Re: 64 SHP Cam and lifter identification

Each lifter was worn in with and became a match to the camshaft lobe it was run on. This is why you need to tray the lifters in the order they were in the engine when you remove them. They must go back on the same lobe. New lifters on a used cam are a bad idea as is mixing up the originals or using other used lifters. I have installed used lifters, as long as the face is still convex, on a used cam by scuffing the lifter face lightly with 400 emery and never had a problem. This was on a used engine that I am still running some 40 years later. I can't recommend this on a new build especially with upgraded valve spring pressures.

At this point just get a new cam and lifters and be safe.

Tom

[Duke W.]

Re: 64 SHP Cam and lifter identification

Now I understand that the cam was replaced with the LT1 cam but it is a good grind for this engine.

Did you read all the replies?

Duke

[Clem Z.]

Re: 64 SHP Cam and lifter identification

edge orifice lifters are available from Hylift Johnson www.toplineauto.com, 800-441-1400

[Duke W.]

Re: 64 SHP Cam and lifter identification

What's the part number? I searched their online catalog. Cross referencing both the edge orifice and piddle valve OE part numbers came up blank.

Application search didn't work. The earliest year it would give me is 1971, which is okay because the edge orifice was used on the LT-1, but the only manufacturer it showed for '71 is Mazda.

Duke

[Clem Z.]

Re: 64 SHP Cam and lifter identification

What's the part number? I searched their online catalog. Cross referencing both the edge orifice and piddle valve OE part numbers came up blank.

Application search didn't work. The earliest year it would give me is 1971, which is okay because the edge orifice was used on the LT-1, but the only manufacturer it showed for '71 is Mazda.

Duke

when i was at the PRI trade show in orlando they told me the had edge orifice lifters for chevys. give them a call.