What would happen if this were to be done?
njdaewoo

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86 Tramaro 90% Trans Am/ 10% IROC/Z (nose, hood,& fenders)
Trans Am Mods as of 1/10/01
3inch
T.E.S/Flowmaster setup,gutted cat,gutted maf,relocated mat,373 gears,upgraded factory chip,255 lph walpro f/pump & throttle body coolant bypass
njdaewoo@excite.com
New mods as of 6/10/01:
383sb engine
Comp Cam Xteme XR264hr-12
smog pump by-pass

 

No,you can't run hydraulic lifters on a solid cam or vice-versa.The way the ramps of the lobes are designed and the way the profile of the lobes are ground.They are made specifically for each other,you might get away with it for a little while,but it wouldn't be worth it.You will be doing the same job twice.

 

Not that I would do it anyways, but WHY???? I don't see why solid rollers wouldn't work on a hydraulic roller cam, besides for noise and the knock sensor problem or stock valve train parts(springs/pushrods) not being able to take the abuse. As for hydraulic rollers on a solid roller cam, I could see the ramps being too steep for the heavy hydraulic rollers to follow, creating a lot of problems. But not the other way around.

 

Several things come into play, but before anything the springs you use for the solid roller normally have 200+ lbs seat pressure. A hydraulic lifter can't stand much more than 130 before it compresses internally. If you go with a lighter spring, it won't pull any more rpm that it would if you went with a hyd-roller.

 

Not to mention that a roller cam is generally made of a harder material than a flat-tappet cam. The hard surface is to provide a good wearing surface for the hardened rollers on the lifters, and will quickly wear the flat lifters into a concave until they're trashed.

Couple that with the fact that a roller profile has none of the necessary taper ground into the lobe to force the lifter to spin slightly, and the idea should be completely in the toilet.

That is not to mention the fact that the profile is not ground to operate a flat lifter at the correct ramp and rates...

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Later,
Vader
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If you want to beat the World, it might reach up and pull you down...
Adobe Acrobat Reader

 

No, he is asking about using a hydraulic roller cam with solid roller lifters.... I would think it would work just fine as both are roller setups, but give Comp Cams a call or email and you will get the correct answer.

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1987 GTA L98 MD8
355, TFS Heads, LT4 Hot Cam
My GTA

The Minnesota F-body Club

 

What is it your trying to achieve?

It still comes down to springs.
Are you planning on using the hyd-springs?

Then, just adding solid rollers to a hyd-cam will not increase the rpm band. You can accomplish that with a hydra-rev from AFR better than anything.

Hydro-roller cams are not agressive enough to provide any benefit by just adding the solid roller lifter. The solid roller is lighter but not sufficent to make much difference.

The main benefit the solid cam provides is higher lifts. That is also what helps add to the hi rpm power. Larger valve openings allow the engine to breath better at higher rpms

[This message has been edited by jcb999 (edited November 06, 2001).]

 

JCB999 is correct on the reasons why you can't use Hydraulic Rollers on a Solid Roller cam. The reason people go to Solid Rollers in the first place is because of they want an extreme cam profile with long .050 duration, fast ramps and high lift.

As jcb999 said, the valve springs needed by the solid roller cam would collapse the hydraulic rollers, hence you go solid roller. The cam profile of a solid roller cam is so radical (compared to a hydraulic) that it would be a poor street cam - they are intended for racing.

Guys that are into racing are "tweaking" everything anyways, so adjusting the lash of their valves is all "part of the tuning process". But for the street, do you REALLY want to have to adjust your valves all the time? I had a solid cam car once and I really didn't find it much fun adjusting the valves every 3-4 weeks. If you didn't you lost performance and if you left it too long, you possibly caused excess valve train wear. Not much fun.

[This message has been edited by Glenn91L98GTA (edited November 06, 2001).]

 

If you run Solid roller lifters on a Hydraulic roller cam you are likley to ruin both.
The solid set up has gradual clearance ramps ground into the camshaft to take up the .015"
to .030" clearance in the valvetrain before starting to lift the valve. The Hydraulic setup is different. It runs with 0 clearance
and starts to lift the valve almost immediately. If run this way the valvetrain will be overstressed and very noisy. You'd really hear the valves as the crash into
their valve seats and bounce. But only for a while 'cause it would soon self destruct.
If you have solid roller lifters, get a solid
roller (streetroller) camshaft. When adjusted
(lash) properly, will only be slightly more noiser than a hydraulic. All in all
the solid roller will outperform (rpm, power) the hydraulic set up anyways.... BUT! never if ya mix the two...

[This message has been edited by F-BIRD'88 (edited November 06, 2001).]

 

Thanx for the input. I just wanted to see if it could be done because the solid roller lifters are so much more lighter than the hyd. roller lifters.

 

2 comments
1) In the Scoggin-Dickey catalog they say that for a hyd. roller, max spring pressure should be 320lbs. Solid roller is 320+ (as in no limit) They said that to make sure you have enough pressure, go as high as you can without going over the above stated limits. Is this wrong? I am running 285lbs. on my hyd. roller. Is that to much?

2) I wanted a solid roller also, b/c of the weight savings. The engine will have the capability to rev a lot higher before valve float, compared to a hyd. roller due to the weight of the lifter. This assumes all things the same otherwise. If I could do it again, I would go with a solid roller of a comparable size to what I have now.

What are your thoughts on the spring issue?

Thanks,


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Joshua Johnston
1991 Z-28
350, T-5, K&N, Ported Vortec heads, Edelbrock RPM, Holley 750 D.P., HEI, 11.07:1 CR, Comp Cams Roller-.510"/.520"-282*/288* dur., Shorty Headers, Dual 2.5 Exhaust, Dynomax Bullet Mufflers, T&R Motorsports custom air intake, Bald tires

 

The spring pressure is relative to the weight of the total valvetrain,rocker ratio
material of all the parts (mass, strength)
acceleration rate of the cam, rpm etc.
285lbs pressure on the seat is too much for a hydraulic roller 285lbs open pressure is barely enough. for hi perf. It all depends on the individual design. Some factory/marine
rollers don't want or need much pressure at all. Should to be able to rev close to 7000 rpm with the right springs on a hydraulic roller. which is plenty on your vortec 350.
Should make peak power at 6/6500 rpm. Just have to remember if ya go with the big solid roller setup with heavy spring pressures to upgrade to a severe duty valve so ya don't yank the heads off the stems. Just my .O2

 

Seat pressure of springs is more important than open when using a hyd lifters. You probably have about 110 seat. Try to get it to the 120lbs range. You should be alright.

This will allow 7000 rpm shift points with a hyd-roller. http://www.airflowresearch.com/hydrarev.html

It comes down to where does the motor make HP. You need to have peak hp at about 6700 to shift at 7000. A hyd-roller with about 245 degrees duration at 050" can provide that in a 350. Cylinder head restriction will determine peak power rpm more than cam duration. The vortecs will make peak power at close to 6000, you can't do much about that even with porting.

 

You guys nailed it on the nose. The springs I am using are set at 1.79", which gives 110lbs. on the seat, and 285 open. THe Scoggin-Dickey listed numbers I gave were all open numbers. I am using SS swirl polished, undercut valves by Elgin. I have the car pulling to 6500, and shift. I don't really want to know if it will go higher. With the problems I had with broken rocker arms, I don't want to break these. Thanks for the knowledge guys.



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Joshua Johnston
1991 Z-28
350, T-5, K&N, Ported Vortec heads, Edelbrock RPM, Holley 750 D.P., HEI, 11.07:1 CR, Comp Cams Roller-.510"/.520"-282*/288* dur., Shorty Headers, Dual 2.5 Exhaust, Dynomax Bullet Mufflers, T&R Motorsports custom air intake, Bald tires

 

If you used the solid rollers on the hyd roller cam It would still be the same cam and would run about the same. As far as having to adjust them all the time that is a bunch of bull. I ran solid cam before with roller rockers and polylocks and adjustment is rarely needed.

 

This is the correct answer. The rest of the discussion is moot.

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82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R4 (restalled TC). Ported World 305 heads, Crane PowerMax cam. ZZ4 intake, oil pump, pan & baffle. Accel HEI SuperCoil & module. Hooker 2055 headers, 3" Catco cat & 3" catback w/dual-opposite Flowmaster. 2.93 limited slip, Spohn SFCs. AMSOIL syn lubes bumper-to-bumper. Daily year-round driver. Best ET, speed TBD...
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I'll second that and add you could raise the seat pressure to 120-130 and have 300 open which could help prevent valve float better.



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Chronologically challenged. But still kicking!
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Thanx again, Anyone knows where I can get a set of roller lifters for a 87 roller block for cheap?

 

here
http://cgi.ebay.com/ebaymotors/aw-cg...item=597636876