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Discussion Starter · #1 ·
Hello all, i am quite obviously new to the forum, and I come here because I am in a pickle. Yes I realize it is all my fault and I should have never bought eBay heads to begin with. But I am stuck with them now and need to figure out how to make it work. My issue is this, I bought Scorpion 220cc heads for $660 assembled. Everything was fine and dandy, I had to pick up a new intake to cover the ports on the heads ($160 more) some 1206 gaskets ($35 more) and all was good, bought some roller rockers that were on sale (once again probably not a good idea) 7/16 stud 1.6 rollers (steel). I was putting the rockers into the heads when I noticed clearance issues, (I knew I needed longer pushrods anyways, so i ordered a pushrod length tool) it got here, and even going up 1.25" with the tool it barely helps the clearance issue. I noticed the valve springs are a much larger diameter than stock, and much much taller when not installed, I was going to install the factory springs into the new heads to remedy this issue, but I am worried the valve spring will walk and eat up the aluminum. I'm really hoping there is something I am just missing here that I can buy and fix this. Even though these are a cheap pair of heads and a cheap intake, $820 is a lot of money. All help welcomed!
Thanks Guys,
-Nick
 

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Is your clearance issue with the outside diameter of the spring retainer??

Does it look like it could be because the valve tip just isn't tall enough to get the rocker up high enough to give good clearance??

If so, fitting lash caps on top of the valves will probably be your fix.

You are right to worry about the stock spring moving around, it needs to be put on the right size spring locator or in the right size spring cup in order to keep it from moving around on the head and tearing things up.

If you could post a few pictures of your clearance problem, there are several of us here that can probably get your stuff straightened out. Some of use can recognize the problem at one glance
 

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Discussion Starter · #3 ·
Thank You All

Thank you guys so much for the quick responses.
First pic is 1.5 3/8 stud non-roller
Second is 1.6 ratio roller
3rd is how much longer the push rod tool is set than stock.

This is what I am working with, all stamped steel, I am kind of scared to do any trimming (i would hate to break a rocker)

I am just lost right now and would love to be steered into the right direction.

Once again thank you all for the prompt replies!
 

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A couple of questions....are those the right springs for the cam you are using?? Reason I ask is that they look pretty stout, if you are using a flat tappet cam they look like they will be way too much pressure causing the cam to wipe out lifters and cam lobes....catastrophic failure.

Second thing is with springs of that diameter, there is just no way to use a stock type rocker that has a pivot ball.....you need to step up to needle bearing roller rocker arms in order to get them to fit. The broblem is how big the rocker needs to be to fit around that pivot ball, and that puts the rocker right into the spot the spring needs.

A full roller rocker arm is under-cut in that area just so it will have enough clearance.

And no, you can't grind the type rocker arm you have to make it fit, you will either grind right through the side or it will soon fail because it is so thin.
 

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Discussion Starter · #5 ·
I have guide plates, but the tool I bought will not fit with guide plates installed,
car was originally hyd flat tappet, and is staying that way. I like the sound of these lash caps. How exactly do they work?
Thank You,
-Nick
 

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Your wanting to use old style ball rocker arms. They're not made for larger springs due to their design. You need true roller rockers as shown. They're clearanced for larger springs.

 

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I have guide plates, but the tool I bought will not fit with guide plates installed,
car was originally hyd flat tappet, and is staying that way. I like the sound of these lash caps. How exactly do they work?
Thank You,
-Nick
I know just from looking at it, that spring, a dual spring of 1.460-1.550" diameter....is way, way too much spring for a hydraulic flat tappet and any flat tappet cam run with those springs will have an extremely short life. :pain:

Have you got a direct link to the heads you've bought....maybe we can find some spring specifications so we know exactly what you have.

As ScojoDak posted, you're going to need a real roller rocker arm for that size spring, a ball pivot rocker is not going to fit.

Lash caps aren't going to work for you either.

Best fix from this point may be a new set of smaller springs and matching spring locators(or cups), and spring retainers.
 

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Thank you guys so much for the quick responses.
First pic is 1.5 3/8 stud non-roller
Second is 1.6 ratio roller
3rd is how much longer the push rod tool is set than stock.

This is what I am working with, all stamped steel, I am kind of scared to do any trimming (i would hate to break a rocker)

I am just lost right now and would love to be steered into the right direction.

Once again thank you all for the prompt replies!

There is no push rod guide, this will move the rocker stud up allowing the rocker to sit higher that will provide more clearance. With aluminum heads you must either use a sheet metal push rod guide and hardened push rods as they rub the guide and this will wear the sides of non-hardened push rods. the sheet metal guides also require the use of a not self guiding rocker. If you use a self guiding rocker then the sheet metal guides are not used but the rocker stud must be shimmed for the thickness of the missing guide because aftermarket heads assume the end user will install guides so everything aftermarket is dimensioned for that. In some cases you can find studs that are longer by the guide thickness or more than do not require a shim.


Many aftermarket heads use a valve stem than is .1 inch longer than factory production valves. These require everything be moved up at least a tenth of an inch. That means longer stud and longer push rod. Stock parts are out the window with I'd hazard to say with all aftermarket heads,,,PERIOD! This also means the spring may have to be shimmed to established proper operating height. This can also lead into locks that move the key up or down relative to the stick location which raises or lower the retainer which does the same to the spring height. Another trick you gan get into is the need to run lash caps on the valve stem end to gain more height for rocker clearance. This book has sooo many tricks in it to get these damn things to work that it is amazing.


I'm not sure where your headed with the rockers in regard to springs. Those are bottom end roller tipped rockers they are not made and will not survive these things alone or in combination. 1) Spring pressures higher than stock. 2) Lifts above .5 inch. 3) RPMs in excess of 5500 this is a generalization because as the spring pressure goes up with these ball and socket rockers the RPM limit comes down.


I guess we need to talk about how the motor will get used. You've got what appears to be some racing stuff like big stiff springs mixed with what is just a slight improvement over stock in the case of the rockers. But over all not just about these parts we need to know more detail. The parts advertisers, the magazines and YouTube vids, plus your buddies can easily lead you astray if you don't do this a lot.


Large diameter springs often require that the rocker be clearance, this cannot be done with the type rocker you're using, it requires a cast or extruded roller trunnion rocker to get enough material to where you can carve notches without running into a bearing surface.


Bogie
 

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Well, the ad has no actual spring spec's at all, just the generic "fits hydraulic flat tappet cams", which doesn't really tell you anything useful.

You'll either have to call them and see if they will give you actual seated and open spring pressures, and if they won't tell you your next option is to have a local shop test one of those springs for you to find out real world specifications for that spring.

Lack of the guideplate under the stud is not going to effect anything as far as rocker clearance or geometry is concerned, as the stud stays on the same axis of centerline no matter how high or low it is screwed into the head.

The fact you say the springs are "much easier to compress than a set of new standard size springs" is disconcerting to me.
 

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I mic'd the springs OD is 1.397"

SBC Aluminum Heads 220cc/64cc Runners Small Block Chevy 350 383 FREE SHIPPING | eBay

There is a link to the heads I bought.
Summit offers full rollers for $225 that have a max spring diameter of 1.625".

Also, I pulled a spring out of the head, and it was much much easier to compress than a set of new std size springs I had previously bought.
-Nick

Don't confuse Scorpion heads with Scorpion Racing Products who make roller rocker arms and other parts.


These heads are imports that's not to say they are bad but they are an older generation with a somewhat simpler combustion chamber. They are rather like some of the older World heads in this regard.


It would be helpful to have your camshaft specs, a part number and manufacturer would be great, but if you have them the duration and lift numbers are important as these relate exactly as to what kind of springs you need. Generally these import heads do not have high quality springs they tend to lose their initial rate pretty fast. The work is often not as clean as it needs to be, it is well worth you time to pull the valves to clean their stems and the guide bores really, really, really good. Then oil the bores with a good engine oil and let it soak in for a couple days. Then follow up with assembly gel before putting the valves back in. You probably should also use a fine grit lapping compound to lap each valve to its seat, do this really at some point after a through initial cleaning of the stems and bores, work hard not to get this grit onto the stems nor into the guide bores. This will let you see the seal you're getting, often these imports have problems with the valve seats matching well enough to make a tight seal. This again is not to condemn import heads this is something that always should be done. Tony Sizemore at Headbytes went off on a set of poorly done, very expensive Dart heads, so this is just something that has to be checked out no matter who's head.


I'm pretty sure these heads use a .1 longer valve stem than the stock GM head, you need to measure the height of the valves as they set on a table top the stem tip, this is going to play big time on the length of the push rod and the position of the rockers on their studs. The roller tip cast rockers you have are nice for moderate RPMs and spring pressures otherwise the ball and socket go up in smoke. This is another place where zinc in oil plays an important role similar to how it functions between the cam lobes and flat tappets. This is one of those areas where the oil cannot form a wedge as it does in crank and rod bearings so lubrication of these highly loaded parts is always a problem; hence the fill roller rocker. Larger than stock 1.25ish springs also have clearance problems unless you use beehive or conical springs which I highly recommend as they keep much better control of the valve with less pressure than straight wound springs. Unfortunately more cost, the best way to buy heads is bare as there are a lot of good deals out there on valves and valve train parts which let you tailor the parts to the cam on one hand and most of this stuff can be found with pretty good discounts for better quality parts than is usually put on these import heads.


Bogie
 

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You can get a rough idea of the spring rates using a scale and your drill press. A local engine machines shop will do it for you pretty quick. I'd take that all and check them all as it's a 15 minutes deal. Cost around here is $40. If you keep track of the numbers you'll have a reference to spring life on the next go round.
 

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The reality is this. A spring pressure from 115 - 125 lb seat and 280 - 300 open pressure is all flat tappet cast iron cams can tolerate with no lead oils. Solid lifter steel billet camshafts can handle 126-160 lb seat pressure and 301 - 380 lb open pressure with no lead. If your camshaft is radical enough to need more spring pressure in order to avoid valve float at high RPM, get a roller camshaft.

Keep in mind that those loads will be reduced by 10% after break in. It is difficult to beat the 2.60" OD SB Chevrolet Z-28 valve springs for flat tappet cams. You can machine the spring pockets .125" deeper to fit hardened steel spring cups that will prevent the Z-28 springs from dancing on the oversize aluminum head's spring seats. Install a set of Elgin 943 (Z-28) valve springs at 1.700" . The Pioneer/Elgin 943 (Z-28 ) valve springs have 10 - 15 lb more seat and open load than the GM Z-28 valve springs that they were designed to replace. The Z-28 valve springs are still available from GM,.

The GM Z-28 valve springs were used on my 1962 Chevrolet Bel Air 327/300 double hump heads in 1968 with a GM "151" L79 camshaft. Both are still running good today with no valve float up to the 5,500 RPM shift points.
 

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Mousefink....you can't guarantee that he can machine the spring pockets .125" deeper on his heads to fit your idea....most aluminum heads have a restriction that you can cut the spring seat to a bigger diameter, but NO deeper. It will either be too weak or will actually break through into the port. Unless you've done it with the heads he has got, you don't actually know.

A correct diameter spring locator would be a much smarter idea than cutting it to hold a cup.
 

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Before cutting the spring pockets deeper, contact the manufacturer to see how much deeper you can safely machine the heads. It is a common practice to deepen the spring seats in order to use steel spring cups on aluminum heads. That protects the soft aluminum heads from being chewed up by the valve springs. The steel cups are .050" thick. The steel spring cup diameter varies. In order to use Z-28 valve springs that are 1.260" OD,, steel spring cups that are 1.300"" OD would be required.

Those cups would prevent the Z-28 valve springs from dancing on the aluminum heads which would eventually cause the springs to fail.

You must ask yourself, why use 1.260" OD valve springs with a maximum of .500" valve lift on heads designed for 1.550" OD valve springs with a maximum of at least .650" valve lift? That appears to be a combination of mis-matched parts.
 

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A 2.02 valve on a 220cc sbc head....Not a good combination.

We're all shooting in the dark with this guy. All we know is he bought bargain heads off Ebay with big valves and ports having mushy springs and that his cheap rockers won't clear the valve retainers.


Somehow he expects all of this to bolt together and if it doesn't it's the head's fault, whew maybe my wife is right I should retire and take up golf.


Bogie
 

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dang bogie he started this by saying it was his fault. Not like hes the first to want more and willing to give it a go.

To the OP its not the head most likely just some new ways of working with after market parts over oem parts which pretty much fall into place. Here there is a bit of figuring. Without going with known brands and builds it sometimes leads to these type of problems which end up costing a few bucks. We all got a box of brand new parts will never use. Its happens stick the rockers back in the box and get some better ones.

Scorpion roller rockers if you can swing them. not to bad in price but not the same people as the heads I think. There are a few other makers of cheaper roller rockers but should be able to get it worked out.

The heads are 220cc and flow almost 300cfm at .600 lift with good cam and .600 rockers he should be able to make some power.

Just need to get it sorted out with correct springs and rockers and pushrods.

Is your cam hydraulic might want to get some oil in those lifters. Also use a very light spring for checking the pushrods. You can grab some from the hardware stores.

Like these so you can make sure the springs arent collapsing the lifters making the numbers off.

Proform 66793 Valve Check Springs | eBay

Just to make sure your not getting throw off. You can also make a valve lift checker from a small piece of all thread and regular pushrod cut in half and threaded so you can check it with your guide plates in stalled. I do like the thicker adjustable checker you got but also like to have my rocker studs in there final home and torqued down before i check em. Im sure its not a big deal just what i would do. Just put the threaded section near the lifter so it doesnt get hung up with the guide.

Maybe I just getting grouchy and missing things I just looked in my lunch bag now that it's long past lunch and headed into dinner but only to find I didn't take my heart meds. That explains my growing inability to focus that leads to frustrations that I take out on everyone nearby.


However, unless I missed some answers to the questions I've asked about this build I find myself blindfolded while trying to hit a piñata. I have no idea if the heads he bought satisfied any other requirement of the engine other than they were (I'll say inexpensive rather than cheap). I ask for technical information that would allow any of us to make useful inputs to and for him. He or someone is off taking about cutting eighth inch deeper spring pockets. I guess that's OK if you're drilling for water but a little cam information would be mighty helpful. Does the bump stick need mighty inch and half diameter valve springs, how about dampers or a triple wind, would beehives be a better solution??? Beats me! An original cam; does that mean a Chevy production cam, that shouldn't need much spring nor 2.02 valves at the end of ports that are 200 ccs big. Or s it a Voodoo or an XE or some other large lobe hydraulic that's going to take something more than stock GM springs or something different than the springs that came on the heads that just happens to be the cam currently residing in the engine.


A 200cc ported head on a stock production cam assuming it isn't an original LT1 engine or some other factory hot rod from back when is going to prove to be a lot of port area for a production cam. This either has to be mitigated in the selection of say the intake or it has to be stepped into.


It's late and I'm going skiing and beer tasting for the weekend.


Bogie
 

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Mousefink....you can't guarantee that he can machine the spring pockets .125" deeper on his heads to fit your idea....most aluminum heads have a restriction that you can cut the spring seat to a bigger diameter, but NO deeper. It will either be too weak or will actually break through into the port. Unless you've done it with the heads he has got, you don't actually know.

A correct diameter spring locator would be a much smarter idea than cutting it to hold a cup.

. A valve spring locator would be a better than machining the spring seat for
a spring cup. With a spring locator, you precisely fit the spring locator by machining the valve guide. . Unfortunately, you must find a spring locator that fits the valve guide OD and the ID of the valve spring with no more than .005" clearance.

I don't know how much you can machine the spring seats of aluminum heads in order to fit the spring cups. That is why I suggested that the manufacturer should be contacted for that information.

The question remains. Why use aluminum heads with bone crushing valve springs with a mild hydraulic camshaft? The problems created outweigh the weight savings. This is a good example of mismatched parts. A pair of double hump or Vortec heads would be mor appropriate.
 
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