I plan on a cam swap this spring and with the newer springs and retainers now out there it was making me consider a hyd roller from Lunati by Harold.

Is it worth the extra cash for springs, pushrods, lifters etc.

My other choice is a Lunati Voodoo Hdy flat cam.554/.572 276/284 110/106

All in a 10:1, 489, iron ovals ported 2.19/1.88 SS valves, 2500 stall, 3.50 gears. RPM Airgap and Holley atop.

I had a hyd roller in a street 454, nothing wicked, but worked just fine. Actually one of my first grinds was one of harolds hyd rollers (UD HR4- 4000lbs/113mph).
If you have the extra bucks, don't need the feel of a high rpm mill, then by all means..
There certainly is a feel to a solid lifter that can't be matched, but for street fun @ under 6200, I don't know if a hyd roller can be beat..
However, with my track record, advice is not warranted. However, I do think a nice, well picked hyd roller *is* the solution for long term low maint., fun, BBC..
I would also like to note that the HR4 had a nice rumble..

Matt

Youve got to consider the purpose of a hydraulic roller and your goals. Basically, the purpose is to provide all the mantenance free usage of a hydro camshaft, yet the added power benefits of a roller camshaft. Youve got a lot of displacement to work with. So what are your goals. If you want to run streetable 12's with that big of a motor, I see no reason why a descently specd hydraulic wont do the job without having to dish out the cash for the roller. But if you still want that mantenance free and driveability of a hydro, yet all the perofmance you can possibly muster out of the 489, than the hydro roller is the most suitable thing. So once again, what are your goals for everything including performance and type and amount of useage for this motor? You may or may not need to step up to a more expensive hydro roller to meet your particular needs.

Is there a rev "limit" for a hyd. roller? Ralph

I wont say there is a definite limit, cause I dont push the limit. My own personal preference, if I am attempting to build an engine that spins much over 6000rpm(6300-6400) and make big power at the same time, Id be looking at something mechanical. For example, if I was building a small block chevy, and using a cam over say 236 at .050(something capable of 6500+rpm in a 383), I wouldnt be using a hydro roller. Once it gets that large, I personally would rather have a solid flat tappet or solid roller camshaft. Now with the updates in valve spring technology that seem to spring up all the time and rev kits an all that, Im sure many have pushed them harder than that. But I dont like the though that I need the newest, trick valvesprings and probably a rev kit just to run consistent between say 6500-7000rpm. I think you will find that most people will say the "limit" for an average valvetrain with a hydro roller camshaft is in the 6000rpm neighborhood. Notice I said average, cause you can do better if you spend the cash. Thats just me. Hopefully we will hear some personal experience from guys that are running them real hard and we can hear what it takes.

Originally posted by Ralph67:
Is there a rev "limit" for a hyd. roller? Ralph It takes a very good combination of parts & the correct lobes to get a hyd roller much over 6000.
Can it be done, yes, I know of a number going to 6500 or so.
Also remember it is harder in a Rat because of valve train weight.

A recent example:
406 sb with 350lbs on the seat & a 90 lb rev kit would not go over 5900 without a drastic loss in power,, read lifter pump up or valve float or both with a well known "extreme" type cam.
Same engine with a different brand cam of about the same specs on paper, no rev kit & same springs only a few pounds less due to being used.
No other changes,, 6400 & still going.
Test was stopped here because it was past the power peak but it was still quite stable.
BTW, the first cam had only 2000 miles & was already showing signs of "tracking" with the approx 440 lb load on it.
It wasn't the same as a 440# spring on the valve because of rocker multiplication, probably closer to a 425# spring without doing the math.

Another example ;) regarding power & a hyd roller
Here is an engine I did a while back I have posted info about before
AFR 315, Vic Jr, 1"spacer 850 Demon, Comp roller 254/260- .698/.666-111 sep, Isky Red Zones, 9.8 compression, 2" dyno headers
670HP@ 6300 @ 610lb ft @ about 45-4600.
Over 500 ft lbs from 2900.
Idled about 850, don't remember the vacuum
This was on a dyno considered pretty conservative,,, Mine :D
Also this engine was pulling over 2" of vacuum from around 5000 on up which means the carb was too small.
Add about 1 point of compression and a little more carb & I have no doubt it would have gone over 700 honest HP.

This engine was originally built with a Comp hyd roller that broke a link bar on the fifth dyno pull. (needless to say I do not use Comps rollers any more!!)
It made the same 610 lbs ft but the Hp was 620 at about 5900

The Hyd roller was a Comp XR294

Mike, what was the displacement of that motor?

So I plan on a few trips to the drags. A trip to Chevelle-abration, and lots of smokey burnouts around the outside of town.

I'd like to make power through 6300-6500 rpm. My current cam seems to fall flat around 5500.

The tranny govenor it set to shift automatically at 6000 and I don't manually shift it but I'd like it not to feal like it is falling flat there.

When it was a 454 and had the 274 XE Comp in it it pulled hard up to that point. Comp reccomended the 280 in it now and I'm disappointed.

I'd like to push 525-550 HP.

I guess a stock hyd might be my choice for cost and ease. But thought a Hyd roller might be a better choice.

It would be nice to run low to mid 12s but who knows.

A hydraulic roller on a BBC can be made to work to about 6500. Above that the valvetrain is too heavy and it will start to float. If you increase spring pressure to compensate the lifters collapse. Now that I said that I'm sure someone will come along with a 7000 rpm hydroller and call BS, but this is my experience.

If you want to run a 6k redline I highly recommend a hydroller. You can build a 500 honest hp with close to stock driveability very easily. Heck, my little 454 makes 500 hp with a baby hydroller cam, only 224/230. It has several years of daily driving on it with no problems.

I know, I know, But what's wrong with a decent solid lifter cam here??

Say one that's right at 290 or so advertized duration??

But I'm a solid lifter cam sorta guy....

pdq67

Originally posted by pdq67:
I know, I know, But what's wrong with a decent solid lifter cam here??
Nothing wrong at all. I opted for the hydroller as mine is a true daily driver where I turn the key and expect to go. Didn't want to clatter and valve adjustments. But if you're ok with that (and it's no big deal, of course) a good solid cam is an excellent choice.

Hyd.lifter cam Hmmm... I've always run the LS6 solid lifter set up, until my resent rebuild. I dropped the compression from 10.23 to about 9 to 1 and installed a hyd roller cam 550 lift 235 duration. I didn't like it at first, different rpm range. I changed rear gear from a 3:73 to a 3:42 and a 27" tire, now this cam works much better. It has gobs of low rpm power I can cruise a 1400 rpm in 4th gear and eazyly pull away with out down shifting. The hard part is getting used to shifting early. Red lines at 5500rpm but only makes power to 5000 rpm, so 5000 is about it. But I must say that this cam pulls very hard on the top end, their must be lots of torque. Idles nice at 690 rpm. Excellent street cam, good city driving manners. Dave

Dsr: Something's up with your combo. That cam should pull higher. I'm running a smaller cam, 224/230, and my power peak is 5300 (454 cui). It doesn't loose much above that. Makes same power at 5800 as it does at 5000.

Originally posted by 427L88:
Mike, what was the displacement of that motor? =
489

Originally posted by Whittaker:
So I plan on a few trips to the drags. A trip to Chevelle-abration, and lots of smokey burnouts around the outside of town.

I'd like to make power through 6300-6500 rpm. My current cam seems to fall flat around 5500.

The tranny govenor it set to shift automatically at 6000 and I don't manually shift it but I'd like it not to feal like it is falling flat there.

When it was a 454 and had the 274 XE Comp in it it pulled hard up to that point. Comp reccomended the 280 in it now and I'm disappointed.

I'd like to push 525-550 HP.

I guess a stock hyd might be my choice for cost and ease. But thought a Hyd roller might be a better choice.

It would be nice to run low to mid 12s but who knows. You will be very happy with a hyd roller under those conditions.
A Comp XM296HR should work pretty decent or better, contact Harold about some of his new stuff.
The Comp "Marine" cams are on a 112 off the shelf which I prefer in a bigger engine plus they appear not as aggressive as the regular XR stuff.
My first choice would be to have the thing ground on a billet core with the cast gear option though.
Then you can run some spring without killing the cam,

Zwede: I don't what to tell you, the engine guy told me before hand it would only go 5500 rpm and he was right. And the power drops off alot above 5000. This is with all new parts, cam, springs (same springs used in LS6), lifters, push rods, dist. etc. It's a cam he uses in his off shore boat engines. Even at 5000 rpm I would say this cam makes more power than the LS6 set up at 6200. Never had it on a track or dyno, but it sure is not lacking in top end power, really hauls as* from 60 to 100mph and way more low rpm pull than the LS6 cam. Dave

Ok Mike as your opinion is respected i would like to run this past you, what does a solid roller do besides allow more rpm? What extra maintenance and how will it effect cruisability and long distance drives? Thanks Ralph

Originally posted by Ralph67:
Ok Mike as your opinion is respected i would like to run this past you, what does a solid roller do besides allow more rpm? What extra maintenance and how will it effect cruisability and long distance drives? Thanks Ralph =
Well,, it allows more RPM :D

In the case of the engine I was referring to, it was worth 50hp at only 4-500 RPM higher.
Last I heard it had about 15,000 miles on it & the lifters still looked like new.
225 on the seat & 550 open pressures
Key here is a good lifter & enough spring to control the valve train.
You may need to adjust the valves once in a while, I believe this one is checked at oil changes but have been told it would easily go longer.
In my opinion, no more maintenance than a solid flat tappet but I do feel it should be checked with regularity, especially if you like to lean on it a bit ;) & if you find something out of the ordinary like a loose adjustment for no apparent reason don't just tighten it,, find out why,, no big deal, just a little common sense.

I have a number of small blocks runnin around with rollers & some have pretty hi mileage as far as I know, one for sure has like 40,000 on it.
Also lots of circle track stuff that has 4 or 5 seasons on engines with rollers that I would have preferred to rebuild a couple of times now but some people like to run em til they die :rolleyes:

Wolfplace(Mike), you mentioned that the motor you built originally had a XR294HR in it(broke a lifter bar) and made 620hp at 5900rpm?
Was that cam the same one Comp Cams catalog shows as having only .540/.560 lift?

Originally posted by SILVERSS454:
Wolfplace(Mike), you mentioned that the motor you built originally had a XR294HR in it(broke a lifter bar) and made 620hp at 5900rpm?
Was that cam the same one Comp Cams catalog shows as having only .540/.560 lift? Yes but with 1.8's on the intake

I run the XR294HR in my 496, revs to 6k while still making prodigious power.

1hot67

Was it worth the extra cash for the hyd roller?

I have a theory on the lower lift that Comp has built into their hyd rollers. I suspect they went to this to control peak spring pressures on the cast cores. And for most street applications with either stock or mild modified heads you probably don't gain much in real world power when the lift gets over .550 in a roller anyway. Now go to some aftermarket heads designed with .600 and up lift in mind and different story. But those guys are probably going to consider a solid roller anyway - whole different ballgame being played.

Regarding Comp Cams hydrollers: They will make you a high lift hydroller but it is special order. It comes on a steel core with cast iron distributor gear. I've been running one for several years now and it works fine.

I'm sorry, Mike.

It is a big deal to me b/c I don't call pulling the intake part of a tune-up..

That's why I'm not going to run a solid roller..

We are way past the old days when a GOOD tune-up meant pulling the heads and "de-coking" the valves and intake ports too is all.

AND I really want that hp I'm leaving on the table TOO!! If I can't run my motor like I did my old junk 301 with the little-bitty -097 solid cam in it, I don't want that cam.. BUT that's just me is all..

pdq67

Originally posted by pdq67:
I'm sorry, Mike.

It is a big deal to me b/c I don't call pulling the intake part of a tune-up..

That's why I'm not going to run a solid roller..

We are way past the old days when a GOOD tune-up meant pulling the heads and "de-coking" the valves and intake ports too is all.

AND I really want that hp I'm leaving on the table TOO!! If I can't run my motor like I did my old junk 301 with the little-bitty -097 solid cam in it, I don't want that cam.. BUT that's just me is all..

pdq67 You don't need to be sorry,,,
Whatever blows your skirt up is fine with me,,, :D

But,, who said anything about pulling the intake :confused:
I don't know about you but I normally just pull the valve covers to adjust the valves & check the springs.
If I find something I don't like that's a different deal,, just like I assume you would do with a flat tappet cam.
If you find a loose rocker for no apparent reason you don't look any further??
As I said, I have a number of solid rollers running happily along without issues as do a number of folks on this board but I ain't tryin to say they are right for everyone, just that they make more power & are normally pretty reliable if done right.
Flat tappet stuff goes bad sometimes too but that don't make all flat tappet stuff bad either :rolleyes:

Originally posted by Whittaker:
1hot67

Was it worth the extra cash for the hyd roller? It was to me. ~600 reliable and relatively maintenance-free HP is nice.

I run a large hydraulic roller (244/254, .580"/.610", 110 LSA) XE cam in my '97 Z28 (383, LT4 heads, 290cfm @ .600") and spin that to 7k (to the limit of the PCM) with no float on a set of 977 springs and comp R lifters. It makes the cam in the '67 feel tame.

EDIT: the flow number quoted is at 0.600" lift.

Originally posted by 1hot67:
</font><blockquote>quote:</font><hr />Originally posted by Whittaker:
1hot67

Was it worth the extra cash for the hyd roller? It was to me. ~600 reliable and relatively maintenance-free HP is nice.

I run a large hydraulic roller (244/254, .580"/.610", 110 LSA) XE cam in my '97 Z28 (383, LT4 heads, 290cfm @ .550") and spin that to 7k (to the limit of the PCM) with no float on a set of 977 springs and comp R lifters. It makes the cam in the '67 feel tame. </font>[/QUOTE]So,, you have a set of LT4 heads that outflow some of the best 23 degree heads on the market?
And you are spinning a hyd roller to 7000?

Interesting,,,, :rolleyes:

BTW, what cam is that?

Originally posted by Wolfplace:
So,, you have a set of LT4 heads that outflow some of the best 23 degree heads on the market?I'm proud to say I do, although they weren't cheap. Advanced Induction in NC performed all the port work, testing and assembly. My heads rival cnc'd AFR LT4 210's, although they edge mine out a bit in the mid lift numbers and have a slightly better overall i/e ratio. I already owned the LT4's, so I opted to have those worked.

Originally posted by Wolfplace:
And you are spinning a hyd roller to 7000?
Interesting,,,, :rolleyes: Yep - right near the limit of the PCM (7,200). You act like you're in disbelief. I admit it's near the upper operating threshold limit of a HR.

Originally posted by Wolfplace:
BTW, what cam is that? If you really want the specifics, call Scott Davis at Comp Cams - he'll let you in on the lobes used and supporting valve train. The cam is a proprietary grind specific to AI, and I do not have the lobe information handy.

Originally posted by SS MPSTR:
</font><blockquote>quote:</font><hr />Originally posted by Wolfplace:
So,, you have a set of LT4 heads that outflow some of the best 23 degree heads on the market?I'm proud to say I do, although they weren't cheap. Advanced Induction in NC performed all the port work, testing and assembly. My heads rival cnc'd AFR LT4 210's, although they edge mine out a bit in the mid lift numbers and have a slightly better overall i/e ratio. I already owned the LT4's, so I opted to have those worked.

Originally posted by Wolfplace:
And you are spinning a hyd roller to 7000?
Interesting,,,, :rolleyes: Yep - right near the limit of the PCM (7,200). You act like you're in disbelief. I admit it's near the upper operating threshold limit of a HR.

Originally posted by Wolfplace:
BTW, what cam is that? If you really want the specifics, call Scott Davis at Comp Cams - he'll let you in on the lobes used and supporting valve train. The cam is a proprietary grind specific to AI, and I do not have the lobe information handy. </font>[/QUOTE]Disbelief,, no,, just a bit skeptical but I guess all benches are different.
I see you changed your flow data to .600

BTW again, what is an AFR LT4 210?

Not saying you can't do it but without some serious port relocation & welding, yes, 290cfm at .600 lift seems a bit "exuberant" from a stock casting.

It may well be a proprietary grind but it isn't any XE lobe I know of although it's very possible they have some new ones. ;)
As for 7000 rpm, if the cam is set up like a solid with the right springs & light parts yes it's very possible but for any normal hyd roller setup as most consider them,, I'll just leave it at yes, I am a bit "skeptical :D

I think it is feasible that the tach is reading 7000, but I would be willing to bet that if the motor was dynoed, there is a nice drop off of power (do to valve float) after 6300-6400. A motor can still spin and fire, doesn't mean it is not still producing any power, but the curve falls off real fast. Kinda like hitting a power peak then watching the curve fall off, only more severe. Everyone thinks valve float is easily identified by misfiring, but that's not really the case. On top of it, the PCM is probably helping to correct the situation, thereby further masking any misfiring. Personally, I have never known anyone that could document a power curve above 6500 with a hyd tappet of any type.

Originally posted by Wolfplace:
Disbelief,, no,, just a bit skeptical but I guess all benches are different.
I see you changed your flow data to .600Yes, I relied on memory, which proved to be a mistake. Not the first time this has happened, and probably not the last smile.gif

Originally posted by Wolfplace:
BTW again, what is an AFR LT4 210?210cc LT4 SBC racing cylinder head. Generation II sbc reverse cooled, raised runner, 23* head. Offered from AFR bare, 70% ported and competition ported.

Originally posted by Wolfplace:
Not saying you can't do it but without some serious port relocation & welding, yes, 290cfm at .600 lift seems a bit "exuberant" from a stock casting. My flow numbers were achieved with some aggressive port work, but no welding. Core shift in production certainly limits the potential of the stock castings, but AI has gotten over 300cfm on sets of LT4 heads before with no welding. I can understand your skepticism, as I was too until I saw it myself.

Originally posted by Wolfplace:
It may well be a proprietary grind but it isn't any XE lobe I know of although it's very possible they have some new ones. ;)
As for 7000 rpm, if the cam is set up like a solid with the right springs & light parts yes it's very possible but for any normal hyd roller setup as most consider them,, I'll just leave it at yes, I am a bit "skeptical :D Well, my valve train is not the normal HR setup, and after many calls to Comp to get it right, I think we do.

Originally posted by GRN69CHV:
On top of it, the PCM is probably helping to correct the situation, thereby further masking any misfiring.Interesting comment...can you elaborate?

Originally posted by SS MPSTR:
Well, my valve train is not the normal HR setup, and after many calls to Comp to get it right, I think we do. Ok, we're listening. What have you done?

Originally posted by TJC:
Ok, we're listening. What have you done? It's set up 'like' a solid, but with Comp R lifters, 3/8" custom length push rods, ti retainers, modified 977 springs, Ferrea valves (2.02/1.560) , stainless 1.7/1.6 rockers, etc. Come to think of it, it's really not that different from other HR set-ups (depending on application), but it has been specifically suited to my combination using a chassis dyno, LT1edit, data from Comp Cams, and data logger.

We're tuning the car now, and converting it to speed density for more finite control of the fuel and spark data. After it's tuned, I'll post the graphs that will either prove or disprove whether a HR can spin to 7k and still make appreciable power. It may fall off or flatten considerably at 6600 or so, but so far everything looks promising and we have not seen what we consider to be valve or lifter float. The car has other issues right now not related to valve train - between the injectors and fighting with idiosynchrasies within the factory PCM (OBDII), it has been a battle.

Are those the magnum lifters or something new?

Pro-Magnum Hydraulic #875-16. Comp has revised the design somewhat recently, but it's basically the same lifter.

tnx, I'll have to look into those.

Ok, I understand now, these are not retro roller design lifters..... I can see the rpm potential now.

Interesting stuff.
Been so long since I sold an LT4 head, let alone the 210 I forgot they even made it,, :D

Ok, given how your valve train is set up I am less "skeptical" of 7000 or close to it.
With the right parts & attention to detail as you have described 7000 or close to it is very possible, just a bit misleading to most of the folks here with what would be considered a more common hyd roller setup which is pretty much done at around 6000-6400, with exceptions, depending again on lobe specs & valve train dynamics especially in a Rat which most seem to run here.
In a small block, 6500 is very good & 7000 takes just "slightly" more work as you have described & is bordering on a solid roller configuration :D
I personally know of one LS1/6 type deal that routinely goes to 7000 but the LS1/6 valve train is very light with 8mm stems, beehive type springs etc.
Belongs to a relatively "unknown" cylinder head guy named Tony Mamo, the gentleman who is responsible for the new AFR BB heads & the LS1/6 heads.

Regarding head flow I never say never & at 290 at only .600 that is one of the best flowing stock casting unwelded 23 degree heads I have heard of & my hats off to whoever got them there.
I am not a head porter but have flowed a lot of heads & if it flowed that on any honest bench it is outstanding graemlins/thumbsup.gif

Thanks for the detailed explanation & apologies for the skepticism ;)

Don't know the late models in/out, just been playing with the LT1 in the '94 here and there, but we are thinking about taking the car off the road and going over it next winter.

Just curious,with the OBDII, are you running both sets of O2 sensors or O2 sims in the rear?

A big advantage to the late model SBC is the cam base cirle is much larger and promotes smoother valve action. Combining all that with a programmed PCM and I would think the valve float and any combustion problems that occur are adjusted at the extreme rpm range. Whereas a non-computer car will continue to flow full fuel and spark at WOT yielding the ever familiar breaking up that we know when a motor sees valve float, the PCM should detect a change in Air Flow and adjust the fuel to maintain a clean fire. Power is most likely down, but the motor is still firing smooth.

Having grown up driving cars with carbs and distributors, the FI/computer scene is at first a little daunting. But the more I am exploring it, I realize just how cool all this is and exactly what performance potential exists. The '94 350 LT1 is probably going to become a LT4 383 motor, or at the very least a well massaged LT1 383 motor with a step up to something around a 3.90 - 4.10 gear.

By the way, my son's buddy has a bone stock '97 LS1, 6 spd car with nothing more than a cat back and a reprogrammed PCM. I have driven the car a few times and shifting at 6300-6400 is nothing for it. The '94 LT1 motor in the 6 spd Formula has headers, high flow cat and a cat back along with a repropgrammed PCM, shift it at 6200-6300, still smooth. May be falling off the power curve at 5800, but it still goes and sounds real sweet.

Originally posted by GRN69CHV:
Don't know the late models in/out, just been playing with the LT1 in the '94 here and there, but we are thinking about taking the car off the road and going over it next winter.Sounds like a great project. Drop me a line if you have any questions you think I might have an answer to, or a source for an answer.

Originally posted by GRN69CHV:
Just curious,with the OBDII, are you running both sets of O2 sensors or O2 sims in the rear?Front O2's are connected, rears are simulators. I run Jet-Hot (Hooker clone) long tubes with both cats though with a modified y-pipe...not legal, but better than nothing.

Originally posted by GRN69CHV:
A big advantage to the late model SBC is the cam base cirle is much larger and promotes smoother valve action. Combining all that with a programmed PCM and I would think the valve float and any combustion problems that occur are adjusted at the extreme rpm range. Whereas a non-computer car will continue to flow full fuel and spark at WOT yielding the ever familiar breaking up that we know when a motor sees valve float, the PCM should detect a change in Air Flow and adjust the fuel to maintain a clean fire. Power is most likely down, but the motor is still firing smooth.Basically, you're right. The computer controlled car has the ability to save itself in some ways. The knock sensor, as one example, is an invaluable tool in real world applications and as a tuning tool. In regards to valve float detection, you really have to know what your looking at - the PCM spits out tons of data, some real and some that is the result of its own actions. Knowing how to decipher it is crucial. I'm still learning.

Originally posted by GRN69CHV:
Having grown up driving cars with carbs and distributors, the FI/computer scene is at first a little daunting. But the more I am exploring it, I realize just how cool all this is and exactly what performance potential exists.Getting over the intimidation factor is the single largest hurdle. It doesn't help at all that the engine compartment in a 4th generation f-body is very difficult to work in. The Gen II SBC is a proven design, with the only issue to deal with being the location of the distributor (opti-spark) directly under the waterpump. Brilliant idea and concept, but poorly executed.
Luckily, the aftermarket has responded with the LS1-style coil-per-cylinder ignition which has significantly improved the durability of the ignition itself.


Originally posted by GRN69CHV:
The '94 350 LT1 is probably going to become a LT4 383 motor, or at the very least a well massaged LT1 383 motor with a step up to something around a 3.90 - 4.10 gear.The only difference between going LT4 and staying LT1 lies in what top end you want. I chose the LT4 route becasue I had the heads already. Plenty of guys get incredible numbers out of the LT1 castings. AFAIK, the only difference in the LT1/LT4 block is that the LT4 blocks came with splayed 4-bolt mains from the factory. For ~$400, you can easily perform the same modification to your block.

If you're thinking of the power levels of a 383 project, and gears, you might want to plan on a 12-bolt or 9-inch rear. The rears that came in these cars are the same one's GM put in S-10 trucks. Once over the 330rwhp area, they file formal complaints - ask me how I know. smile.gif

Originally posted by GRN69CHV:
By the way, my son's buddy has a bone stock '97 LS1, 6 spd car with nothing more than a cat back and a reprogrammed PCM. I have driven the car a few times and shifting at 6300-6400 is nothing for it. The '94 LT1 motor in the 6 spd Formula has headers, high flow cat and a cat back along with a repropgrammed PCM, shift it at 6200-6300, still smooth. May be falling off the power curve at 5800, but it still goes and sounds real sweet. FYI, the LT1 stayed in the f-body until 1997, and switched to the LS1 platform in MY 1998. However, Corvettes got the LS1 in 1997. Without question, the LS1 is superior in every way. I have a '99 C5 LS1 with very few mods and it flat out flies. Unfortunately, the LT1 is going to need a few more 'tweaks' to keep up with your son's friend's LS1.

I have found that a big cammed stroker LT1 with awesome heads is an effective equalizer of sorts.

Good luck with your late model project.

Originally posted by Wolfplace:
Thanks for the detailed explanation & apologies for the skepticism ;) No problem here at all, Mike. smile.gif

I'll keep you posted on what this thing actually does after the tuning and conversion is complete.

It is most likely a '98 then, definitely has the LS1. By the way, the LT1 work is down the road a bit, probably not start on it until next winter. Right now the car runs and looks good while my Chevelle is slowly being reborn - again.

Very interesting stuff going on here. Not what I thought it would be but good stuff.

Again back to my main question is it worth the extra cash to go with a hyd roller over a flat tappet? Or should I save my money for the Brodix oval port heads I also want.

I'm thinking a bigger flat tappet cam will be my choice. I'll run it to 6000 and let the govenor shift it from there. If I ever get to wild I'll change then.

I gotcha Mike.

In other words, don't pull them out and look at them, but rather only pull them when the lash goes ta h-ll!

Then you know something IS WRONG.. So it's time to look closer with the intake off..

But still, I never lashed my cams until they got to "sewing-machining" too much so DUMB old me would probably not check the lash close enough AND I would eat one anyway.... (And even my hy-cams too -- daily driver deal is all)......

pdq67

Originally posted by Whittaker:
Very interesting stuff going on here. Not what I thought it would be but good stuff.

Again back to my main question is it worth the extra cash to go with a hyd roller over a flat tappet? Or should I save my money for the Brodix oval port heads I also want.

I'm thinking a bigger flat tappet cam will be my choice. I'll run it to 6000 and let the govenor shift it from there. If I ever get to wild I'll change then. Hey Whittaker,, apologies for going south with your original post :rolleyes:

To answer your question, you will gain far more with the heads than you will with the cam.
Both would be great but the better head you have the less cam you need to fill the cylinders as airflow is what these things are all about.
In simple terms, the better you effectively fill the cylinders,, the more power you will make ;)

Whittaker,

You didn't say anything about heads in the orig thread, now that's another story.

I assume you want to stay hydraulic? Check out a custom grind from Isky. They have some .573 and .600+ lift flat tappet hyd's available.

Something like these:
H392/H584 292/298, 244/252, .573/.573 or
H443/H393 296/304, 248/256, .602/.595

You can get these ground on the P55 premium core for under $200.00.

What about using Comp's behive springs to extend the rpm range? I read an article about them and it said they extended the rpm range 950 rpm on a hyd flat tappet cam. This would make 7000 a useable figure on a hyd cam. Not that I am going past 6000 or 6500.

The smaller Isky is close to what I'm looking at but in a Voodoo cma from Lunati/Harold.

What do you think about the beehive springs to reduce weight and mass on the valve train?

Whittaker,

IMHO for what its worth (not much) if the money isn't a problem you have nothing to lose. Properly set up it should go to right around 6000 rpm +- how the cams RPM range is. I had two similar hyd rollers one was done at 5800 one was done at 6100, but would rev to 6400+. There was just no need to rev either of them that far past their useable range.
Its really a non issue though- your 489 doesn't need to go over 6000, I wouldn't think anyway.
Even with the heads, I think you are looking at a "gimmie" 550-600hp 489 with a proper high perf street hyd roller. The last time I shopped around cam motion had the most interesting hyd roller grinds. Other cam companies don't seem to stock as many hyd roller grinds.
At the minimum, you are buying insurance to prevent a tappet from going south and making you pull the engine apart.
This is just my opinion, I don't have any credentials to back it up. But you really can't be hurt from it if the cost isn't a huge factor. There is certainly power over a hyd flat tappet to be had, and some would argue a solid flat..

Good luck..

Matt

Originally posted by Whittaker:
What about using Comp's behive springs to extend the rpm range? I read an article about them and it said they extended the rpm range 950 rpm on a hyd flat tappet cam. This would make 7000 a useable figure on a hyd cam. Not that I am going past 6000 or 6500.

The smaller Isky is close to what I'm looking at but in a Voodoo cma from Lunati/Harold.

What do you think about the beehive springs to reduce weight and mass on the valve train? =

The Beehive's do seem promising but the 950rpm figure is a little optimistic I think.
Don't forget these folks are trying to sell you stuff :D
I have now used them in two applications & in both instances there was a 400-600 rpm increase with less spring pressure.
One is a 383 that went from 5800 to 6400.
the other was a rat that went from about 5700 to just over 6000.
Neither was a controlled test, they were both in vehicles but the 383 test was what I consider pretty reliable information.
It may well have gone further as it could be a cam/ head issue limiting it's potential.
Now this isn't a completely fair test as the springs that came off were not in the best shape so to make things fair & valid one would need to install new "original" springs to see what happened.
The beehive retainers were 14 grams in steel compared to the Titanium ones that came off at 22 or so as I recall but you also have to account for the fact the beehive has a lot less mass in the spring which is also part of the mass you have to control.