Cam swappage

[1987cp]

I'm getting ready to swap out some bad lifters in my 351, and while I don't feel like spending serious wrenching time on the car at this time, I'm contemplating changing the cam out as well. Currently it's got the regular Edelbrock Performer #2122, which the car's previous owner had planned to swap for a a new-in-box cam that came with the car called the EnginePro MC2077. I was at first confused as to why Desktop Dyno was projecting decreased horsepower over the Edelbrock 2122 with peak at the same 4000rpm, but then realized I'd entered the Exhaust Centerline as the Lobe Displacement Angle. Oops!

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Edelbrock 2122 (current; also present in Nathan in MN's P72)

Advertised duration: 262/272
.050 duration: 204/214
Lift: .448/.472
Intake/exhaust centerline 107/117
Nominal RPM range: idle-5500

Desktop Dyno projected output with current heads and intake: 272hp@4000, 412 lb-ft @ 2000 (as with DD 2000, DD2003 doesn't provide data below 2K RPM)

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EnginePro MC2077

Advertised duration: 280/290
.050 duration: 214/224
Valve lift: .472/.496
Intake/exhaust centerlines: 107/117
Nominal RPM range: 2000-4500
Idle quality: Fair

Desktop Dyno projected output with current heads and intake: 284hp@4500, 380lb-ft@3000

Manufacturer Comments: GOOD LOW TO MID RANGE TORQUE. CAN USE STOCK CONVERTER


So I'd lose up to 30 or so lb-ft peak torque, but some of that is exhibiting a tendency to go up in tire smoke anyway.

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It's interesting to compare the EnginePro cam to the Comp profile I'd had my eye on until I decided that when buying a cam I would go roller. The Comp appears to be a more radical profile with its narrower advertised duration but wider .050 duration, but it's funky how close the HP curves come, with the Comp gaining about 15-20 lb-ft on the bottom end compared to the EnginePro (which I've read is the big reason behind the more radical ramp profiles). It'd be tempting to purchase the Comp instead just for this reason, but it'd set me back $120 plus miscellaneae while the EnginePro could cost me as little as a set of intake gaskets. The easiest option is still to leave the Edelbrock cam in place, but that'd mean breaking in at least four brand-new lifters with an old cam.


Comp 35-242-3 (grind XE268H)

Adv. duration 268/280
.050 duration 224/230
Lift .510/.512
Intake/exhaust centerlines 106/114
Nominal RPM range: 1600-5800

DD projected output: 286hp@4500, 407lb-ft@ 2500-3000

Manufacturer comments: Hydraulic-Great for Street Machine, 2200+ stall.

[torquelover]

It'd be tempting to purchase the Comp instead just for this reason, but it'd set me back $120 plus miscellaneae while the EnginePro could cost me as little as a set of intake gaskets.

There is a complete Felpro cam change gasket set somewhere in the big cardboard box I gave you, with a new tube of assembly lube as well. Do you still have them handy?

I'd be curious to see if the cam was a better fit for the car, as the light weight and skinny tires just translates low-end torque into smoke, and the trans wants to shift at 5.5k. You would only be out 2 fresh oil and filter changes, and some time to try this. So hopefully a new set of valvesprings is in the budget. I would imagine the current ones are too tired. There will be more lift, however. How do the valvestems look? Any varnish or build up?

[1987cp]

There is a complete Felpro cam change gasket set somewhere in the big cardboard box I gave you, with a new tube of assembly lube as well. Do you still have them handy?

I'd be curious to see if the cam was a better fit for the car, as the light weight and skinny tires just translates low-end torque into smoke, and the trans wants to shift at 5.5k. You would only be out 2 fresh oil and filter changes, and some time to try this. So hopefully a new set of valvesprings is in the budget. I would imagine the current ones are too tired. There will be more lift, however. How do the valvestems look? Any varnish or build up?

Thanks for reminding me!! They're in the trunk of the 2-door. Suppose I'd have found them while digging out the lifters, but after having purchased a redundant intake kit. Can you tell my brain's been partially out to lunch for several weeks now?

Guess I never posted my rocker pics, but here's a representative image. Everything looked great, a little pooled oil was the only "buildup" detectable. The more I think about it, the more sense this EnginePro cam makes. Just out of curiosity, was the slightly more modern Comp profile above also in the running when you selected this cam?

[1987cp]

Whoops, I'd also forgotten that the currently-installed cam is actually the Summit 4400, but it's nearly identical to the Edelbrock 2122, differing only in a few degrees advertised duration (measured differently, perhaps?) with the same .050 duration, lift, etc.

I didn't see anything about springs in the receipt pile, though it's getting late and my eyes may be being lazy. Do you remember which ones went in there?


In related news, I just found a Comp XE274 (35-246-3) for sale on the Corral. It's used, with 1000 miles on the clock, for $50 plus shipping - spend money to get a used cam .... not ideal. But, DD2003 optimistically predicts very nearly an even 300hp/400lb-ft at 4500/3000 ...... Someone boot me away from the computer and out into the garage!!!

[torquelover]

Oh yeah, the Summit cam is what I used after the rebuild. Pretty much the same specs for the EDEL cam, but available without lifters, as I already had them. I could not detect any difference in quality, either, although the packaging was nicer on the EDEL.

I did not look into any roller cams much due to the cost of conversion. The car had other issues that I needed to work on first, like trying to get it plated.

The pic looks good. You'd never guess the mileage on the motor glancing in there I say.

I would say use the cam that you have, as it was free, and only go hotter after you get some AFRs on that thing.

I believe that cam you found is a roller, is it not? If it is a roller cam, 1000 miles is nothing, and the price is good. It's sorta hot, though, so heads are definitely in order before you convert it over to that one, too.

[Pirate]

Go with a roller cam.



There, I said it.

[1987cp]

Oh yeah, the Summit cam is what I used after the rebuild. Pretty much the same specs for the EDEL cam, but available without lifters, as I already had them. I could not detect any difference in quality, either, although the packaging was nicer on the EDEL.

I did not look into any roller cams much due to the cost of conversion. The car had other issues that I needed to work on first, like trying to get it plated.

The pic looks good. You'd never guess the mileage on the motor glancing in there I say.

I would say use the cam that you have, as it was free, and only go hotter after you get some AFRs on that thing.

I believe that cam you found is a roller, is it not? If it is a roller cam, 1000 miles is nothing, and the price is good. It's sorta hot, though, so heads are definitely in order before you convert it over to that one, too.

Nope, hydraulic flat tappet. Thus the concern about it being used. The conversion rollers I've found all go 35-4xx-8. I definitely see your point about heads, though - and the name of the game at this point is to swap a cam only if it'll work OK with the E7 corkolas still in place!

The $400ish price of crossbar lifters to use with a factory-style roller cam was a big chunk of what talked me out of either doing a 351 for the wagon or buying a fresh professionally-assembled nonroller 302 a guy I know was willing to part with for cheap. After getting Pirate's 20-minute tutorial about the Comp conversion camshafts, I feel very silly indeed!

Go with a roller cam.



There, I said it.

Can't afford it right now. In fact, I doubt I'd be contemplating a cam swap at all at the present time if I didn't already have a reasonably suitable specimen at my disposal, just replace the bad lifters and keep driving unless lobe damage is detected. Still halfway tempted to do that anyway, just because I don't feel like removing and reinstalling water pumps and front covers.

I do still have my eye on the 35-421-8 for when I can swing it ($240 for cam plus $10-$40 for lifter retainers plus up to $150ish for custom pushrods). If I could afford that at this time, I might be buying the Windsor Jrs. the guy with the cam has for sale. Free, on the other hand, I can afford.

Speaking of rollers, DD 2000 always projected an enormous power gain just from switching its lifter type setting from flat to roller. DD 2003 shows no difference at all. I presume the latter is typically more realistic, as the gains to be had with a roller cam come from the fact that it can handle considerably more radical ramp rates?

[gadget73]

The gains are more from increased ramp rate than reduced friction, but the reduced friction certainly doesn't hurt. The thing you'll have to be concerned with on a flat tappet motor is the lack of zinc in the oil these days. It causes excessive wear on older motors. You might need to search around for separate additive, or go to a race formula oil that has it. Used to be able to use diesel oil but its been removed from that too. Roller cams don't have this requirement.

Honestly I'd be spending money on heads before a cam. Big cams and heads that don't breathe don't yield especially impressive performance.

[351m]

Shell Rotella T is your friend according to comp cams. At least thats what it said in the break in papers when i got the new cam for my old Iron Duke...

[1987cp]

The gains are more from increased ramp rate than reduced friction, but the reduced friction certainly doesn't hurt. The thing you'll have to be concerned with on a flat tappet motor is the lack of zinc in the oil these days. It causes excessive wear on older motors. You might need to search around for separate additive, or go to a race formula oil that has it. Used to be able to use diesel oil but its been removed from that too. Roller cams don't have this requirement.

Yeah, I've worried about that on this motor already, which is why it got Mobil-1 "Turbo Diesel Truck" oil for its last oil change, and it's helped prejudice me against the idea of installing another flat-tappet camshaft (aside from having to worry about break-in procedure). Have to find a cheap dino oil with high zinc content for break-in, I suppose. Seems I'd actually read that Rotella doesn't have zinc anymore ... although, I found this PDF at the Mobil website that suggests that all their Mobil-1 products, at least, have some amount of zinc/phosphorus additive, just in varying amounts.

Honestly I'd be spending money on heads before a cam. Big cams and heads that don't breathe don't yield especially impressive performance.

I had originally wanted to do heads before even touching the cam, and then this lifter thing came up (or rather, I figured out what it was). Would you particularly recommend against swapping in the non-enormous cam I already have at this stage in the game, and just replace the lifters instead? 214/224 .050 duration isn't generally thought of as all that "big" on a 5.8L engine, from what I understand.

[gadget73]

well no, the cams you've listed aren't big, that was just a general statement. I'm just generally a fan of allowing the engine to breathe before adding more cam.

I didn't realize (read: read the entire post) you had some issue with the parts in the car that required replacement. Whats wrong, one of the lifters is damaged? Unfortunately whenever I've seen a ruined flat tappet lifter, its also damaged the camshaft so unless its a matter of the lifter not pumping up, you might be forced into a cam change.

As for the Rotella T, from what I've heard that used to be the magic stuff for flat cams, but apparently its been re-formulated to remove the zinc content. I don't know this as gospel though.

[Southern_Pride]

Rotella removed some zinc, but from lab test I've seen its still about the highest out there. It's still the only oil I use. Roller cam or not I swear by it.

[P72Ford]

John Deere 15W40 >> Rotella.

My personal experience says this. We use it in everything (except for my new Ram); I have conversed with folks at JD via email, and they have confirmed that they do have a larger quantity of anti-wear additives than most other oils. They would not reveal exactly what they are using, as that is 'proprietary information'.

We have tried Rotella, and whereas it is good, it just isn't the same. The 350 Oldsmobile in our '81 caprice Wagon has 300+K miles on it, and it looks new inside; no deposits, and it still runs like a top, and holds great oil pressure.

The same is true of the 351 in my P72. My Dad has used it in diesels, lawn mowers, personal cars, pick-ups, gas engines, diesel engines, etc. It is the best he has come across. Yes, you can only buy it at the local John Deere dealer. 75 bucks for 5 gallons.

If you are doing break-in, you will be elated to know that JD makes a break-in specific oil, as well. It does contain zinc among other essentials.

http://www.frontierpower.ca/service/breakinoil.htm

http://www.deere.com/en_US/parts/partsinfo/oils_and_lubricants/oil_0w40.html

A friend and I recently broke in the engine in the Monte Carlo, using regular Rotella, and two bottles of Comp Cams additive. No issues.

[1987cp]

Break-in additive?! Dang! All the things one doesn't have to think about when using a roller setup! I like the sound of a dedicated break-in oil, though, so maybe I'll see if that's cost-effective compared to getting that additive junk. I had always assumed people broke in flat-tappet cams using plain store-brand conventional oil and plenty of cam lube on the cam itself and nothing else.

It's funny, I distinctly recall seeing John Deere engine oil at a nearby Tractor Supply Company location, but I can't find it on their website. Can't find any other leads offhand other than a Deere dealer about five miles south of here, so I guess I'll plan to give them a call sometime this week.

Why 15W40 and not the 10W30 or 0W40 they advertise on Deere.com?

[torquelover]

The cam lube will just keep the lobes lubed up until the regular engine oil starts to circulate. Since you'll be priming the oil pump, I wonder how much of this is left after priming? The last 2 cams in that car were broken in with non-synthetic straight 30 weight oil. Using the JD break-in oil or conventional oil with an additive should do a great job.

Comp Cams and Crane both sell some break-in additives. Should be easy to find. Do you know how to properly break in a flat-tappet cam in regards to engine temp and RPM? I will warn you right now that the 2-row radiator in the car is not capable of doing the job during break-in.