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Discussion Starter · #1 ·
Hey fellas,

First let me start off by saying that I am NOT looking for a COMP/Lunati cam. I just wiped out a Lunati cam due to lifter failure, and I don't like anything that I've heard about COMP lately. I want nothing to do with crappy cam cores or junk offshore lifters. I've been looking at Crower, since they actually carry Hylift Johnson lifters.

Since I wiped out this Lunati cam, I'm looking for something that works with my current setup so I can just slap it in. I'm not looking for a mechanical flat tappet (would need to send heads to get machined for threaded studs) and I don't want a roller (I don't want to spend more money replacing my brand new timing set, springs, etc). I'm just looking for a quality flat tappet cam/lifter setup that will last. The TRW cam I pulled out was in there for 25+ years. Anyway!

Here's my build:

355 (.030 over) 10:1
Stock cast crank
SCAT Forged 5.7" I Beam Rods
Sealed Power flat top pistons w/ 4 valve reliefs (+6.90cc)
Melling 10552 HV Oil Pump
Cloyes C-3023x Heavy Duty Double Roller Timing Set
Stock Iron 906 Vortec Heads
FelPro 7733SH1 .016" Steel shim head gaskets
LS6 Valve Springs 12499224
COMP 787-16 Retainers
COMP 1.52 Steel stamped self aligning roller tip rockers
Edelbrock Performer RPM Intake
Holley 4160 600cfm vac. secondary carb
Stock GM HEI

TH400 w/ 9.5" FTI 2400-2600 stall
3.42 rear gears

Full weight '73 Camaro with power brakes, so I would like decent manifold vacuum. Car is street driven, but I beat the **** out of it, so it WILL see 6000 RPM's.

Just to give you an idea, this is the Lunati cam that I chose (and it felt pretty damn strong until it wiped out):

227/233 dur @ .050 / .489/.504 lift 110LSA / 106 CL

I've been loking at Crower, Howards, and Isky. What do you guys think?
Thanks!
 

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Discussion Starter · #3 ·
If your going to run a cam with specs like you sight on the street your best to belly up to the bar and order a roller nobody’s flat tappet is going to be happy without you buying hard faced lifters and getting the cam Parkerized. By the time you spend the money for that you’re into roller cam territory.

Bogie
Hey Bogie. Thanks for your response, I've seen a bunch of great replies from you during my lurking around here.

So, if I were to go roller, what all will I need? I have an early one piece rear main seal block ('88 I think?) that has the cam retainer bolt holes drilled and tapped, as well as the holes for the spider tray. However, I'm guessing I will need a different timing set, cam retainer plate, valve springs, and to get my heads set up for screw in studs to handle the higher lift of a roller. At this point I feel like I'll be near $1000 in parts.
 

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I imagine you're aware that because you wiped a can that your engine is now full of powdered metal . I you don't tear it down & wash it out , you're running the risk of early failure ,( bearings , rings , etc.) I know you don't want to hear that but that's the way it is . One of the advantages of running a roller cam is you can increase the duration without increasing the lift , keep that in mind when making your decision . Competition products markets Howards cams ( flat tappet) with a " no fail" guarantee , worth considering for your can choice ..
 

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Just curious why a mechanical flat tappet requires threaded studs, but hydraulic flat tappet does not.

I feel much better when using my windage tray, to use a Crower solid flat tappet with P55 core and Howards direct-lube solid lifters. Put it all together with roller rockers and valvetrain is VERY light weight/capable of a bit more RPM if that matters to you. For your engine a 00320 grind would be very good. You might have to custom order if you want a P55 core on that particular cam.

Or you could go with a roller cam and switch all the associated parts. This is the solution if you are not willing to take the needed precautions when running a flat tappet cam.

You did coat with proper camshaft break in lube and use real break in oil like Lucas 30W/correct procedure - then switch to real hi-ZDDP formulated oil like Brad Penn?

Better tear that engine down completely for thorough cleaning or you are destined for more problems. Metal particles get everywhere!

Good luck and best wishes.
 

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Hey Bogie. Thanks for your response, I've seen a bunch of great replies from you during my lurking around here.

So, if I were to go roller, what all will I need? I have an early one piece rear main seal block ('88 I think?) that has the cam retainer bolt holes drilled and tapped, as well as the holes for the spider tray. However, I'm guessing I will need a different timing set, cam retainer plate, valve springs, and to get my heads set up for screw in studs to handle the higher lift of a roller. At this point I feel like I'll be near $1000 in parts.
If your block is drilled and tapped for the thrust plate and the valley bosses are there and hopefully drilled and tapped then you cam use a factory OEM roller cam.

To support the cam requires the thrust plate and its round head machine screws plus a set of eight dog bones that align the factory style lifters and the spider that bolts on the valley bosses (3 places) that keeps the dog bones aligned.

Obviously a set of OEM roller lifters, GM’s are just fine.

The roller lifters are taller than flat tappets they use a shorter 7.2ish inch long pushrod. If you need hardened for guides they are available.

If your using a mechanical engine driven fuel pump you’ll need to shop for a cam with a fuel pump lobe. Both GMPP and the aftermarket provide.

For a reasonably priced timing set that lasts and lasts I recommend SA Gear part number SAG78150. This is a double roller, the cam gear will likely require you dress the top of the main oil galley protrusion in the timing case for cam gear clearance.

Yes this is more expensive than a flat tappet but most likely this will be the last time your in there to replace the cam and lifters.

Bogie
 

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1979 Chevrolet Malibu 496-TH400-9" (cruiser). 1992 Chevrolet S10 355-700r4-7.625" (daily driver).
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Last summer I helped out with a build eerily similar to this one (2nd gen Camaro, TH400, 3.42, roller block with flat tops, 9.8 compression and 3000 converter). I'm a shade tree guy and I really only get involved with other projects by word of mouth. I get a text "so and so says you tinker with cars. I'm building a such and such. I could use some help/advice on this or that." It keeps me learning and thinking, much like this forum, but I digress.

That Vortec head really needs more of an intake/exhaust split than the 6 degrees @.050 of the newly deceased camshaft you listed. Double that would be a start. Oddly, this is a scenario where a "thumpr" camshaft actually makes some sense. We can do better than that though. Those cylinder heads tend to hit a wall much over .500 lift and as 2old2fast stated, we can maintain a target valve lift across various durations. The duration numbers on the roller camshafts aren't exact equivalents to the flat tappet camshafts. The roller "acts" 6 to 8 degrees larger. Take the advice others have given and go roller. Don't look back. For your consideration:


  • Part. No. 150-3100
  • Adv. 280/294
  • .050”221/235
  • .100 191/204
  • .200 140/150
  • .300 74/79
  • Lift .510/.510
  • Centerlines 104/112
  • Lobe Sep 108
The sticker price of these "semi-custom" style grinds are worth it, in my opinion. Given that you have the roller block, you can "economize" somewhat on a roller conversion. This camshaft was literally made for what you are trying to accomplish here. I saw this combination run and sound amazing! He has no trouble on pump gas in the summer. I did the basic screw in stud install on those heads when I ported them. I'm not sure I would trust a pressed in stud.

Just an observation on the rest of what you have. If you do disassemble, find debris and go looking for a new oil pump...ditch the HV. Go with the old M77 Melling, get the "purple" relief spring M77020 (not difficult to install) and call it good.

This is my attempt at a "quick and dirty" broad strokes kind of recommendation. I'm not any kind of an expert. I mainly build and break my own things with an occasional outside project. I'm just making a jumping off point for others on a recommendation based on what I think I understand, hahaha. I'm as interested as you are in what the folks that really know what they are talking about come up with.
 

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Discussion Starter · #8 · (Edited)
I imagine you're aware that because you wiped a can that your engine is now full of powdered metal . I you don't tear it down & wash it out , you're running the risk of early failure ,( bearings , rings , etc.) I know you don't want to hear that but that's the way it is . One of the advantages of running a roller cam is you can increase the duration without increasing the lift , keep that in mind when making your decision . Competition products markets Howards cams ( flat tappet) with a " no fail" guarantee , worth considering for your can choice ..
Unfortunately I am indeed aware, lol. My filter and magnet appeared to catch a lot of it, just don't know how much more is in there.. definitely doesn't seem like a good idea to run it.

Just curious why a mechanical flat tappet requires threaded studs, but hydraulic flat tappet does not.

I feel much better when using my windage tray, to use a Crower solid flat tappet with P55 core and Howards direct-lube solid lifters. Put it all together with roller rockers and valvetrain is VERY light weight/capable of a bit more RPM if that matters to you. For your engine a 00320 grind would be very good. You might have to custom order if you want a P55 core on that particular cam.

Or you could go with a roller cam and switch all the associated parts. This is the solution if you are not willing to take the needed precautions when running a flat tappet cam.

You did coat with proper camshaft break in lube and use real break in oil like Lucas 30W/correct procedure - then switch to real hi-ZDDP formulated oil like Brad Penn?

Better tear that engine down completely for thorough cleaning or you are destined for more problems. Metal particles get everywhere!

Good luck and best wishes.
I was told that the solid flat tappet's have more of a "jackhammer" effect on the valvetrain than the hydraulic. With lifts above .500 combined with a solid, I start to lose faith in the press in studs.

Yeah, I used the proper break in oils and all that. It appears that a lifter failed. It started clacking away shortly before I tore everything down to check it out.

If your block is drilled and tapped for the thrust plate and the valley bosses are there and hopefully drilled and tapped then you cam use a factory OEM roller cam.

To support the cam requires the thrust plate and its round head machine screws plus a set of eight dog bones that align the factory style lifters and the spider that bolts on the valley bosses (3 places) that keeps the dog bones aligned.

Obviously a set of OEM roller lifters, GM’s are just fine.

The roller lifters are taller than flat tappets they use a shorter 7.2ish inch long pushrod. If you need hardened for guides they are available.

If your using a mechanical engine driven fuel pump you’ll need to shop for a cam with a fuel pump lobe. Both GMPP and the aftermarket provide.

For a reasonably priced timing set that lasts and lasts I recommend SA Gear part number SAG78150. This is a double roller, the cam gear will likely require you dress the top of the main oil galley protrusion in the timing case for cam gear clearance.

Yes this is more expensive than a flat tappet but most likely this will be the last time your in there to replace the cam and lifters.

Bogie
Thank you very much for another informative post!

Last summer I helped out with a build eerily similar to this one (2nd gen Camaro, TH400, 3.42, roller block with flat tops, 9.8 compression and 3000 converter). I'm a shade tree guy and I really only get involved with other projects by word of mouth. I get a text "so and so says you tinker with cars. I'm building a such and such. I could use some help/advice on this or that." It keeps me learning and thinking, much like this forum, but I digress.

That Vortec head really needs more of an intake/exhaust split than the 6 degrees @.050 of the newly deceased camshaft you listed. Double that would be a start. Oddly, this is a scenario where a "thumpr" camshaft actually makes some sense. We can do better than that though. Those cylinder heads tend to hit a wall much over .500 lift and as 2old2fast stated, we can maintain a target valve lift across various durations. The duration numbers on the roller camshafts aren't exact equivalents to the flat tappet camshafts. The roller "acts" 6 to 8 degrees larger. Take the advice others have given and go roller. Don't look back. For your consideration:


  • Part. No. 150-3100
  • Adv. 280/294
  • .050”221/235
  • .100 191/204
  • .200 140/150
  • .300 74/79
  • Lift .510/.510
  • Centerlines 104/112
  • Lobe Sep 108
The sticker price of these "semi-custom" style grinds are worth it, in my opinion. Given that you have the roller block, you can "economize" somewhat on a roller conversion. This camshaft was literally made for what you are trying to accomplish here. I saw this combination run and sound amazing! He has no trouble on pump gas in the summer. I did the basic screw in stud install on those heads when I ported them. I'm not sure I would trust a pressed in stud.

Just an observation on the rest of what you have. If you do disassemble, find debris and go looking for a new oil pump...ditch the HV. Go with the old M77 Melling, get the "purple" relief spring M77020 (not difficult to install) and call it good.

This is my attempt at a "quick and dirty" broad strokes kind of recommendation. I'm not any kind of an expert. I mainly build and break my own things with an occasional outside project. I'm just making a jumping off point for others on a recommendation based on what I think I understand, hahaha. I'm as interested as you are in what the folks that really know what they are talking about come up with.
That does sound like it's pretty much right on the money. Thank you for the information, I'm going to look into this a little more.

Hey, did you machine down the rocker arm stud bosses before installing the screw in studs?
 

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1979 Chevrolet Malibu 496-TH400-9" (cruiser). 1992 Chevrolet S10 355-700r4-7.625" (daily driver).
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Go with the old M77 Melling, get the "purple" relief spring M77020 (not difficult to install) and call it good.
This is incorrect information. The big block guy in me rattled off the wrong part numbers. I should have said to run the M55a pump.

On those Vortec heads I have had great luck with the cheaper screw in studs that use the existing hole from the pressed in stud. There is a tool you can use to orient the tap to the hole.

Pioneer Automotive 850001 - Pioneer Rocker Arm Studs

Summit Racing SUM-900136 - Summit Racing™ Stud Removal Tools or the Comp Cams tool.

I'm sure a lot of folks cringe at this idea but I have had great luck with it. There are some informative videos on YouTube demonstrating it. This guy does a nice job explaining it. Hopefully some others can chime in about this. If this is a bad idea, perhaps others have better advice. The last thing I ever want to do is steer someone in the wrong direction.

 

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Im gonna say something unpopular.....HFT, nothing wrong with it, a good cam core and a good lifter and the right break in and it'll be just fine.
Going to roller, you'll end up $1000-$1500 in, sticking with a good HFT, Less than $500.
Get on the phone with a cam company and request a P55 cam core and hard faced lifters.
 

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As far as Isky is concerned, one of their Mega-cams may be a good fit. Take a look at 201281 280-Mega Hydraulic...


Valve lift will be a little higher with the 1.52 rockers @ .4915
I have this cam in my '67 Camaro with a 350, I've had it for years and love it, flat tappets or not. I've got lots of miles on it with no issues. I'm actually installing another one in a new 383 stroker, great street cam.
 

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Im gonna say something unpopular.....HFT, nothing wrong with it, a good cam core and a good lifter and the right break in and it'll be just fine.
Going to roller, you'll end up $1000-$1500 in, sticking with a good HFT, Less than $500.
Get on the phone with a cam company and request a P55 cam core and hard faced lifters.
While most of my HFT builds have been pretty vanilla/street/boat builds, I agree. If properly broken in, a flat tappet cam will run for an incredibly long time. The HFT I put in my 454 in 2003 now has 140k on it, and I use regular Penzoil or Castrol in it. Didn't even use high ZDDP oil for break-in. I did use assembly lube that was higher in ZDDP, but once it's broken in, they're good. Quite possible you got a defective one. The HFT that came from the factory in my Caddy 500 lasted 524k miles. Only reason I rebuilt it was because it was burning a lot of oil, but the cam was fine.

EvilWS6, If you end up disassembling to clean it and discover that you don't have a roller block, now is the time to remedy that. For $150 you can find a good used roller block and use it for re-assembly. You'll need a 1-to-2 piece conversion thing to put your crank in the newer block, but you'll save well over a grand instead of doing a roller conversion.

There have also been some people who have done a poor-man's conversion, but it involves some sketchy stuff. The roller lifters from a 2.8-3.1L V6 family are the same bore size, but almost as short as an SBC flat tappet lifter. The sketch part is that you have to drill into the oil gallery in the valley and tap for the spider retainer.

There are many ways to add a roller to a non-roller block... all of them expensive and/or sketchy. Since you may be tearing down for a cleaning, the cheap solution is to start with a roller block (if you don't already have one.)
 

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I have this cam in my '67 Camaro with a 350, I've had it for years and love it, flat tappets or not. I've got lots of miles on it with no issues. I'm actually installing another one in a new 383 stroker, great street cam.
I hope you realize it is going to act much milder in the larger 383 cube engine.....the 3.75" stroke just sucks up duration like a sponge.
It won't act or sound like it does in the 350.
 

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I hope you realize it is going to act much milder in the larger 383 cube engine.....the 3.75" stroke just sucks up duration like a sponge.
It won't act or sound like it does in the 350.
Eric,Hadn't thought of that. Haven't heard that before, I may switch to something more aggresive with the retro roller lifters. Got any suggestions? I've had trouble with Comp Cams rollers, so would rather stick with Isky. Thanks, Bill
 

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Discussion Starter · #17 ·
Im gonna say something unpopular.....HFT, nothing wrong with it, a good cam core and a good lifter and the right break in and it'll be just fine.
Going to roller, you'll end up $1000-$1500 in, sticking with a good HFT, Less than $500.
Get on the phone with a cam company and request a P55 cam core and hard faced lifters.
I was surprised to hear how many people just went straight to suggesting a roller. But with the HFT lifter reputations lately, I do understand. I think the key here is to use the right lifter, like a Hylift Johnson or a Delphi style with a hardened face.

My Camaro had a flat tappet for over 25 years, and we always just put whatever oil in it. By the time the car was given to me (8 years ago) I was just putting Mobil 1 in it. Upon disassembly, everything was fine - just normal wear. That's what made me want to go back to a HFT in the first place.

As far as Isky is concerned, one of their Mega-cams may be a good fit. Take a look at 201281 280-Mega Hydraulic...


Valve lift will be a little higher with the 1.52 rockers @ .4915
I may not have enough gear for that, but I'll take it into consideration and browse the catalog. Thanks!

While most of my HFT builds have been pretty vanilla/street/boat builds, I agree. If properly broken in, a flat tappet cam will run for an incredibly long time. The HFT I put in my 454 in 2003 now has 140k on it, and I use regular Penzoil or Castrol in it. Didn't even use high ZDDP oil for break-in. I did use assembly lube that was higher in ZDDP, but once it's broken in, they're good. Quite possible you got a defective one. The HFT that came from the factory in my Caddy 500 lasted 524k miles. Only reason I rebuilt it was because it was burning a lot of oil, but the cam was fine.

EvilWS6, If you end up disassembling to clean it and discover that you don't have a roller block, now is the time to remedy that. For $150 you can find a good used roller block and use it for re-assembly. You'll need a 1-to-2 piece conversion thing to put your crank in the newer block, but you'll save well over a grand instead of doing a roller conversion.

There have also been some people who have done a poor-man's conversion, but it involves some sketchy stuff. The roller lifters from a 2.8-3.1L V6 family are the same bore size, but almost as short as an SBC flat tappet lifter. The sketch part is that you have to drill into the oil gallery in the valley and tap for the spider retainer.

There are many ways to add a roller to a non-roller block... all of them expensive and/or sketchy. Since you may be tearing down for a cleaning, the cheap solution is to start with a roller block (if you don't already have one.)
As I said above, I've had a similar experience with the HFT that was in my car. It's definitely a late 80's roller block - the one's that went into trucks. Has the roller provisions but setup with a flat tappet.
 

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I was surprised to hear how many people just went straight to suggesting a roller. But with the HFT lifter reputations lately, I do understand. I think the key here is to use the right lifter, like a Hylift Johnson or a Delphi style with a hardened face.
I can't speak for everyone that suggested going roller, but my recommendation was based on the fact that you do have a roller block already. Given that the cam profile for this application isn't going to be "wild" in any way, the GM style roller lifters and related parts (shorter pushrods, cam retainer, dog bones, spider, timing set) aren't crazy expensive.

I agree with the folks thinking flat tappet is good here, too. I have never had a hydraulic or solid flat tappet fail in anything. I have known people that have and they seem to walk around with the idea that "today might be the day my cam frags itself." If you're the type that is going to worry about it all the time, the added expense of the roller set up may be worth it for your peace of mind.

In the end, I don't think you can make a bad choice here either way. If you're doing your research, using proper set up, break in and maintenance, you're good.

Whatever you do, I would suggest looking into something split duration over a single pattern. Single pattern cams have their uses, their benefits and are ideal with certain cylinder heads. I just think this situation, with those cylinder heads, calls for more exhaust duration. I'm thinking tighter lobe separation too. Something on a 108. Overlap is more than just making a choppy idle.
 

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Eric,Hadn't thought of that. Haven't heard that before, I may switch to something more aggresive with the retro roller lifters. Got any suggestions? I've had trouble with Comp Cams rollers, so would rather stick with Isky. Thanks, Bill
Add about 6-8° duration to it, and tighten the lobe separation angle 2-4°.

Looking at Isky catalog, next bigger hydraulic flat tappet street cam than 280 Mega is 292 Mega, which has 12° more duration but no LSA change.
that's a big jump....I'm not crazy about it.

If you look into what Isky lists as "oval track" there are some good street aggressive crossover grinds there.
The 286Mega .500" lift rule cam #201286/6 has 8° more duration and the 2° tighter LSA.
The 284Mega .510" lift #210284/6 has 4° more duration and the 2°tighter LSA.
Take your pick.
 

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Add about 6-8° duration to it, and tighten the lobe separation angle 2-4°.

Looking at Isky catalog, next bigger hydraulic flat tappet street cam than 280 Mega is 292 Mega, which has 12° more duration but no LSA change.
that's a big jump....I'm not crazy about it.

If you look into what Isky lists as "oval track" there are some good street aggressive crossover grinds there.
The 286Mega .500" lift rule cam #201286/6 has 8° more duration and the 2° tighter LSA.
The 284Mega .510" lift #210284/6 has 4° more duration and the 2°tighter LSA.
Take your pick.
Thanks Eric, I'll talk to Isky tomorrow.
 
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