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chevy 400 ci. street

 
skyeking
I mow my lawn and find Chevys
Posts: 2738
Joined: 08/09
Posted: 11/28/11 04:28 PM

Shocked  Hi Guys, Laugh
 Who is working through Xmas Confused  Cool  
skyeking

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BuzzLOL
I have an SS396 tatoo
Posts: 380
Joined: 12/10
Posted: 11/28/11 06:12 PM

.. LOL! You mean who will still have a job by Xmas Day? Or who will actually be working on Xmas Day?  

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greg_moreira
My first time was in a Chevy
Posts: 226
Joined: 07/11
Posted: 11/28/11 08:58 PM

Buzz, to answer your question.....a "true" solid roller lobe is going to make more power than a hydraulic roller lobe.

You may have two lobes that look pretty similar on paper....but they are very different in actuality.  The solid roller lobe is going to be more intense and aggressive.  Because of the amount of spring required to control a solid roller valvetrain, among other things....as a whole a solid roller valvetrain has a hard time living a super long life in a street motor.

It can be done, but its not something that you can just throw together.

A hydraulic roller valvetrain doesnt have a lot of trouble living a good long time on the street.  However.....although they make great power, they are still a little behind a solid roller lobe.

The hybrid setup bridges the gap between hydraulic roller longevity and solid roller performance.  The reason you probably dont see them engineered this way is a two fold reason.

Number one....even though there are tons of solid rollers on the street, and I have no problem with that either....the primary market for a solid roller is a drag engine.  In this application, usually power is more important than anything else.  Guys have regular maintenance schedules and would rather make the most power possible.  So, you wont find cam designers making solid roller lobes "softer" to any great degree(at the expense of power).  Solid roller lobes are going to stay pretty intense.

As for hydraulic roller cams...these are expected to make power, but live long and prosper too.

So, you wont find designers making the lobe profile way more radical in most cases.  Although there are much better lifters out there on the market that brings hydraulic roller closer to solid roller performance....it still isnt a total match.

Necessity is the mother of invention and until enough people start demanding less intense solid roller lobes(which isnt likely to happen too soon) folks will use the hydraulic roller lobe for the same effect, and then mate it to a lifter that has a better power return.  

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Pontiacman2
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Posts: 8956
Joined: 09/08
Posted: 11/29/11 07:33 AM

Icon Quoteskyeking:
Shocked  Hi Guys, Laugh
 Who is working through Xmas Confused  Cool


Hi skyeking.  
Pontiacman2
Pontiacman2

Professional Hi-performance engine builder

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ELIR_MN
I love my Chevy Chevette!
Posts: 3
Joined: 11/11
Posted: 12/01/11 12:41 PM

Public tuffnuff a budget which I look, the parties are THE FOLLOWING:

110245-10 and Howards Howards cams cams roller lifters 91117 but apparently it is wrong to write and 91167
 

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greg_moreira
My first time was in a Chevy
Posts: 226
Joined: 07/11
Posted: 12/01/11 12:54 PM

I like the cam choice.  I do not like the lifter choice.  The 91167 is a hydraulic roller lifter for a big block chevy.  Not going to work in your SBC application.

The 91117 is a solid roller lifter.  I see no need for it with that cam.  Thats a 224 at .050 lobe with somewhat mild valve lift.  In a 400 small block, on its very best day it might spin 6500rpm with the rest of the top end being right on the money but its gonna prefer to be around 6000rpm.

It'll spin 6500 safely with the right hydraulic roller lifter.  It would struggle to get to 6500 just as much however with a solid roller only because is a middle of the road cam thats not going to want to spin super high regaurdless.

Howards 91163 is the lifter you should be using.  Its battle tested.  Tool steel body with 8620 billet wheel and the revised valving for high rpm operation.  FYI these are made by morel Wink

The "street series" are the ones with the captured lifter wheel(smaller wheel inside of the lifter body as opposed to the exposed, big wheel).  The street series lifters like a milder cam and not a lot of rpm.

I've heard good things about the 91160 lifter.  Supposedly designed by an ex crane engineer, but I cant tell you a whole bunch about it and not sure if its really anywhere near as capable as the 91163.  

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tuffnuff
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Posts: 7841
Joined: 12/09
Posted: 12/01/11 02:36 PM

Icon QuoteELIR_MN:
Public tuffnuff a budget which I look, the parties are THE FOLLOWING:

110245-10 and Howards Howards cams cams roller lifters 91117 but apparently it is wrong to write and 91167


Confused

Say that again,,,,,,,,,,,,,,,,,,
Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

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skyeking
I mow my lawn and find Chevys
Posts: 2738
Joined: 08/09
Posted: 12/01/11 04:16 PM

Hi there,
 I won't buy into this but both sides of the debate are
 feasible and I know that to be true..It all depends on
 the rate of lift of the given lobe...End Of story..  
skyeking

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tuffnuff
Moderator
Posts: 7841
Joined: 12/09
Posted: 12/01/11 06:26 PM

Please clue me in, the poster asks for a roller build with Vortec heads and I posted what I already had.,. nothing more, nothing less.
It gets pretty silly,,,,, sometimes, having to read minds,
it would really help if I had a mind to read first.
Hi Skye, no debate.,. at least not for me.
Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

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BuzzLOL
I have an SS396 tatoo
Posts: 380
Joined: 12/10
Posted: 12/02/11 02:48 AM

.. 400" with 224/224 or 224/234 cam sounds like a good basic street performance combo to start from...  

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greg_moreira
My first time was in a Chevy
Posts: 226
Joined: 07/11
Posted: 12/02/11 07:09 AM

haha Im not quite sure I followed the post either.  I just saw part numbers and talked about them a little!

One being a big block chevy lifter, which obviously isnt gonna work for him in the small block build.  And the other being a solid roller lifter.  And although we talked about it....this doesnt look like one of those applications that would show a big benefit.

Skye....the "rate of lift" can mean a lot of different things when talking about a cam lobe.  In short, when you take it all into consideration it should tell you how aggressive a lobe is overall.  You'll often hear this referred to as intensity, or lifter intensity(just a sole number used to try and represent how aggressive a lobe is).

By and large...a hydraulic roller lifter is "less intense" than a solid roller lobe(which will be more intense/aggressive).

If the solid roller lifter can survive on a more intense solid roller lobe....it'll definitely survive on a less intense hydraulic roller lobe.

Its all about the difference in the lash/clearance ramps.  As long as you can work with whats on the hydraulic roller lobe(even though it will always need less lash) then it'll work every time regaurdless of what the rest of the lobe looks like.  

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Pontiacman2
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Posted: 12/02/11 09:22 AM

Confused  
Pontiacman2
Pontiacman2

Professional Hi-performance engine builder

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pepsi1
I mow my lawn and find Chevys
Posts: 1718
Joined: 09/11
Posted: 12/02/11 12:08 PM

Absolutely Greg:I don't know when I last heard or did that. WOW your bringing up some old stuff now!...LOL...

You can lash a hydraulic cam like a solid cam, but you better get it right. Its something like this if I remember correctly is you bottom the lifter and set a .002 lash between the valve and rocker is that the correct way. I can't tell you the last time I did that again it works, but get it right. Correct me if I'm wrong please, like I said it's been a long
time. We can't give all the secrets away...LOL... Cool

Tuff we talked about old school HAH..LOL...  

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pepsi1
I mow my lawn and find Chevys
Posts: 1718
Joined: 09/11
Posted: 12/02/11 12:11 PM

Oh Yeah I'll be here, getting paper work ready for 2012.  Ooo  Laugh  Confused  Cool  

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greg_moreira
My first time was in a Chevy
Posts: 226
Joined: 07/11
Posted: 12/02/11 12:26 PM

You can do it.....but you do have to be careful.

Truth be told....when figuring out your pushrod lenght with any hydraulic lifter...you need to factor in preload.  So like for example if you checked for pushrod lenght with the plunger of the lifter all the way at the top, youd expect the plunger to depress around .050 with around a half turn lash.

So whatever pushrod you figure should be at least .050 longer cause once the preload is actually there...thats your change in lenght.

If you totally bottom it....this is yet another change that will equate to a change in the required pushrod lenght if you wanna keep geometry spot on.

Two other factors.  If  you have a set of lifters that have a tendency to want to pump up as RPM's climb, once that plunger travels up significantly the valves arent going to seal great.

Or, if the valves do float...its much harder to recover from valve float.  Reason being?  

If you float the valves and the weight of the spring isnt acting on the plunger....that gives the plunger the opportunity to pump up since its getting oil pumped in it...yet minimal spring pressure to keep the plunger from rising.  

Granted once the valvetrain gets back in control that'll correct itself.  Spring pressure will squash the excess oil out and you'll get your preload back where you set it.

But...with the plunger almost at the top, there is very little distance to pump up, therefore little time to return to normal preload.

With the plunger depressed nearly to the bottom....thats a lot further distance for the plunger to travel up if the valves float and when the lifters fill with oil.  So naturally...it'll take more time to bleed back down and settle.

This is the kind of thing Id do with a lifter that has good valving designed for high rpm and isnt prone to pump up.  

A run of the mill lifter may give you fits at time.  But yeah, done right...it has proven to be worthy of extra rpm and power in some apps.  Vizard has done some testing with this and had favorable results.

Its definitely kind of along the same lines of using the different style lifter.  

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