Here We Go: My 383 Stroker Winter Project

[greg82255]

Re: Here We Go: My 383 Stroker Winter Project

Forgot the pic of the balancer... here it is:

 

[greg82255]

Re: Here We Go: My 383 Stroker Winter Project

I actually just spoke to the machinist - he says that the holes were drilled when the factory originally balanced the dampener itself and that I am good to go.

 

[SuperNova]

Re: Here We Go: My 383 Stroker Winter Project

Also, it appears that my valve covers fit just fine over the rockers. I test fitted them but haven't installed them yet, and they slid right on without any problems.

When the valvetrain is in motion is when clearance issues will show. You won't be able to tell at first, but when that lifter noise just doesn't seem to go away, check your valve covers for any telltales where the rockers were hitting.

 

[greg82255]

Re: Here We Go: My 383 Stroker Winter Project

When the valvetrain is in motion is when clearance issues will show. You won't be able to tell at first, but when that lifter noise just doesn't seem to go away, check your valve covers for any telltales where the rockers were hitting.

Will it damage anything if I run the motor and just wait until I see where the rockers hit and then grind down those areas?

 

[SuperNova]

Re: Here We Go: My 383 Stroker Winter Project

Will it damage anything if I run the motor and just wait until I see where the rockers hit and then grind down those areas?

Define damage.....at the least it'll leave a mark on the inside of the valve cover and also one on the rocker(s) that is (are) hitting. At worst you may bend a pushrod or break a rocker stud. There is no easy way to check clearance until the lifters are full of oil. Even if you crank it over slowly now, the valve springs will collapse the lifters so you won't be getting full rocker motion. You could just set the valve covers on the engine and not bolt them down, that way if the rockers hit, the covers will move and hopefully prevent any major damage, but you may leak some oil until everything pumps up and you're sure you're ok.

Ideally, rocker-to-valve cover clearance should be checked during mock-up if there may be cause for concern. I think this build falls under the guidelines of having cause for concern.

 

[joewithaboat]

Re: Here We Go: My 383 Stroker Winter Project

Will it damage anything if I run the motor and just wait until I see where the rockers hit and then grind down those areas?

The link you posted earlier on the rockers said they are the "Narrow body" type. They should fit under the stock type valve covers. You don't want to run them if they are going to hit... worse case you could pop keepers/retainers loose and drop a valve.

 

[greg82255]

Re: Here We Go: My 383 Stroker Winter Project

The link you posted earlier on the rockers said they are the "Narrow body" type. They should fit under the stock type valve covers. You don't want to run them if they are going to hit... worse case you could pop keepers/retainers loose and drop a valve.

http://www.summitracing.com/parts/SUM-G6936-16/

Those are the rockers I bought. They are the narrow body type. I don't want any risk of breaking any valve train components so I'd rather just get everything right the first time.

 

[Scott Danforth]

Re: Here We Go: My 383 Stroker Winter Project

use some clay or silly putty inside the valve cover to check clearances. put it above both intake and exhaust rockers on a cylinder. turn the engine over by hand. then check the thickness of the divots in the clay or silly putty that were mushed in there by the rockers. once you have that thickness, subtract about 3/16" for the approximate clearance (or interference) while running.

 

[SuperNova]

Re: Here We Go: My 383 Stroker Winter Project

use some clay or silly putty inside the valve cover to check clearances. put it above both intake and exhaust rockers on a cylinder. turn the engine over by hand. then check the thickness of the divots in the clay or silly putty that were mushed in there by the rockers. once you have that thickness, subtract about 3/16" for the approximate clearance (or interference) while running.

This is a good procedure except for the fact that the lifters have no oil in them, therefore as soon as valvespring pressure exerts any force against them, they are going to collapse down to minimum height, thereby completely screwing up any chances for accurate clearance measurements.

The width of the rocker is not the concern.

The increase in lift is the concern with relatively low stock center-bolt valve covers.

 

[greg82255]

Re: Here We Go: My 383 Stroker Winter Project

This is a good procedure except for the fact that the lifters have no oil in them, therefore as soon as valvespring pressure exerts any force against them, they are going to collapse down to minimum height, thereby completely screwing up any chances for accurate clearance measurements.

The width of the rocker is not the concern.

The increase in lift is the concern with relatively low stock center-bolt valve covers.

Would buying taller valve covers eliminate the possibility of a problem?

 

[John_S]

Re: Here We Go: My 383 Stroker Winter Project

Would buying taller valve covers eliminate the possibility of a problem?

You don't know for sure if you have a problem. Call the head shop and see if they are concerned and how they would recommend you checking.

For taller valve covers you need to make sure they clear the stock exhaust. Automotive companies don't worry about exhaust manifold that exit out the top. They will usually clear, but if you tried to remove the valve covers to adj valves, etc, you might have to remove or loosen the exhaust manifolds, which may require more gaskets and time.

My original concern was from the rockers hitting the cross ribs. I didn't know you had the narrow body style. Comp pro-magnum rockers would have been a problem.

PS: No matter how well you think you adjusted the valves with a dry engine, I recommend re-checking with the hot engine method.

 

[joewithaboat]

Re: Here We Go: My 383 Stroker Winter Project

This is a good procedure except for the fact that the lifters have no oil in them, therefore as soon as valvespring pressure exerts any force against them, they are going to collapse down to minimum height, thereby completely screwing up any chances for accurate clearance measurements.

The width of the rocker is not the concern.

The increase in lift is the concern with relatively low stock center-bolt valve covers.

You are spot on about the lack of oil affecting gross lift measurements.

The narrow body rockers are specifically developed for this type heads/valves cover because the bolt goes between them.

The lift of this cam is not huge as far as rollers go, but he does need to check. Generally the locks are the tallest part of the assembly and hit first.

 

[joewithaboat]

Re: Here We Go: My 383 Stroker Winter Project

There are adapters made to use early type covers, you could also use them as a spacer with your current covers. Pay attention to what John mentioned about getting them too tall and interfering with exhaust.

http://www.jegs.com/p/JEGS-Performa...ly-Style-Valve-Cover-Adapters/757463/10002/-1

If yours do hit these should be a little taller, look pretty good and cost about the same as adapters/spacers.

http://www.hardin-marine.com/p-1366...nter-bolt-valve-covers-extra-tall-height.aspx

Another member here (45auto) is using these, (i think these are the same ones) you might pm him to see what rockers he has and if they come off without loosening the exhaust. They look very similar to the Hardin marine.

http://www.jegs.com/i/GM-Performance/809/12497978/10002/-1?parentProductId=761599

 

[Scott Danforth]

Re: Here We Go: My 383 Stroker Winter Project

This is a good procedure except for the fact that the lifters have no oil in them, therefore as soon as valvespring pressure exerts any force against them, they are going to collapse down to minimum height, thereby completely screwing up any chances for accurate clearance measurements.

The width of the rocker is not the concern.

The increase in lift is the concern with relatively low stock center-bolt valve covers.

since the lifter plunger travel is between .150 and .200 depending on manufacturer, its easy to determine clearance. measure the lifter plunger travel, multiply by the rocker ratio, and bang..... you have the actual movement.

 

[John_S]

Re: Here We Go: My 383 Stroker Winter Project

If the concern of the rocker arm hitting the top of the cover, we are talking about the pushrod side. Don't have to worry about the 1.6 factor. So the amount of cam lift plus some safety factor??? The neoprene valve cover gasket are rather thick and might be enough of a safety factor. I'll be interested in what the head shop says.

From the black scorpion sm, it looks like it is using the stock centerbolt valve covers, with roller rockers. Max cam lobe lift calcs out to 0.353 on exhaust. I won't be surprised if the head shop says it is not even close.

 

[greg82255]

Re: Here We Go: My 383 Stroker Winter Project

If the concern of the rocker arm hitting the top of the cover, we are talking about the pushrod side. Don't have to worry about the 1.6 factor. So the amount of cam lift plus some safety factor??? The neoprene valve cover gasket are rather thick and might be enough of a safety factor. I'll be interested in what the head shop says.

From the black scorpion sm, it looks like it is using the stock centerbolt valve covers, with roller rockers. Max cam lobe lift calcs out to 0.353 on exhaust. I won't be surprised if the head shop says it is not even close.

I'll give the head shop a call in the morning. For what it's worth, I've installed the valve covers and turned the engine over by hand and I don't hear anything hitting. I know the lifters are not full of oil yet though.

John, what do you mean by the hot engine method for checking valve adjustment?

 

[John_S]

Re: Here We Go: My 383 Stroker Winter Project

John, what do you mean by the hot engine method for checking valve adjustment?

To the unexpeirenced, it is easy to adjust the valves too tight using the method you did with the lifters having no oil. And when I say too tight, not to the point that the lifter has bottomed out, but further down then the 1/2 turn or spec you are going by.

Hot method:
After the engine is warmed up, you remove a valve cover and install clips to prevent oil from squirting out (or modified valve cover) and adjust the valves. You back out the bolt until you have have a clacking noise, adj down until noise stops (zero lash), and then another 1/2 turn. I have only done this with standard rockers. Joe or others would have to tell you if there are any modification to procedure with roller rockers.

 

[joewithaboat]

Re: Here We Go: My 383 Stroker Winter Project

To the unexpeirenced, it is easy to adjust the valves too tight using the method you did with the lifters having no oil. And when I say too tight, not to the point that the lifter has bottomed out, but further down then the 1/2 turn or spec you are going by.

Hot method:
After the engine is warmed up, you remove a valve cover and install clips to prevent oil from squirting out (or modified valve cover) and adjust the valves. You back out the bolt until you have have a clacking noise, adj down until noise stops (zero lash), and then another 1/2 turn. I have only done this with standard rockers. Joe or others would have to tell you if there are any modification to procedure with roller rockers.

I find in helping others after they have adjusted their valves that somehow most get them too tight. There are many methods used for determining when the lifter is on the heel or lowest point of the lobe, that seems to mess folks up as well. To iron all this out after the fact the easiest thing to do seems to be to adjust them while running. With roller rockers there is no way i know of to put clips on them, it will make a bit of a mess.
If you have questions about how you have them set let us know what method you used. I think finding zero while the intake is off and the lifter is empty of oil is very simple (because you can see the lifter cup) and have done it many times this way with no need for further adjustment.

The next most common problem I've seen is people getting the distributor 180 deg. out!

 

[billbayliner]

Re: Here We Go: My 383 Stroker Winter Project

Greg, he's talking about dynamically setting cam followers... I.E, engine running and while warm as John S explains.
Two methods can be used.
A dial indicator valve gapping instrument such as the old P&G tool.
Doubt that you have a valve gapping instrument.

Or as John S suggests, we listen for the clatter between the (in your case) the roller tip and valve stem.

Engine warm and at idle, get all rockers to quiet down by initially adjusting them past zero lash.
Go down each, and one at a time, back off on the adjustment until your hear the clatter.
Snug it back down slowly until the clatter is removed.
This is dynamic ZERO lash.
From there, adjust the rocker arm stud nut as per the manufacturer's suggestion, which in turn sets your cam follower plunger depth. That is the goal.

The rocker arm ratio, stud thread pitch, and cam follower design dictate this setting.
IOW, don't use GM's numbers, use the recommendation by your camshaft supplier.
They know more about their cam profile and cam follower than GM does.
The goal is setting the plunger depth correctly.... not the rocker arm clearance. The zero rocker arm clearance will be maintained by the lower value of the hydraulic principle.

.... There are many methods used for determining when the lifter is on the heel or lowest point of the lobe, that seems to mess folks up as well. To iron all this out after the fact the easiest thing to do seems to be to adjust them while running. With roller rockers there is no way i know of to put clips on them, it will make a bit of a mess.
If you have questions about how you have them set let us know what method you used. I think finding zero while the intake is off and the lifter is empty of oil is very simple (because you can see the lifter cup) and have done it many times this way with no need for further adjustment.

Well said Joe, and I am 100% on board with you if you are doing this using the 8 stop procedure.... not the 2 or 3 stop.
With the 8 stop, this is a great oportunity to do the static adjustment while these can be seen. When we do this, most of the time we won't have to go back through them dynamically.

Even though Gregg is now past this, the dynamic method is his next step, and will work well for him. A bit messy, but hey!

 

[greg82255]

Re: Here We Go: My 383 Stroker Winter Project

Greg, he's talking about dynamically setting cam followers... I.E, engine running and while warm as John S explains.
Two methods can be used.
A dial indicator valve gapping instrument such as the old P&G tool.
Doubt that you have a valve gapping instrument.

Or as John S suggests, we listen for the clatter between the (in your case) the roller tip and valve stem.

Engine warm and at idle, get all rockers to quiet down by initially adjusting them past zero lash.
Go down each, and one at a time, back off on the adjustment until your hear the clatter.
Snug it back down slowly until the clatter is removed.
This is dynamic ZERO lash.
From there, adjust the rocker arm stud nut as per the manufacturer's suggestion, which in turn sets your cam follower plunger depth. That is the goal.

The rocker arm ratio, stud thread pitch, and cam follower design dictate this setting.
IOW, don't use GM's numbers, use the recommendation by your camshaft supplier.
They know more about their cam profile and cam follower than GM does.
The goal is setting the plunger depth correctly.... not the rocker arm clearance. The zero rocker arm clearance will be maintained by the lower value of the hydraulic principle.

Well said Joe, and I am 100% on board with you if you are doing this using the 8 stop procedure.... not the 2 or 3 stop.
With the 8 stop, this is a great oportunity to do the static adjustment while these can be seen. When we do this, most of the time we won't have to go back through them dynamically.

Even though Gregg is now past this, the dynamic method is his next step, and will work well for him. A bit messy, but hey!

I did attempt to find zero lash while the intake is off and the lifter is empty of oil. I read several instruction manuals (as well as this thread) that said it was the correct way to do it. It couldn't hurt to also make sure they are adjusted correctly while the motor is running, so I'll do that too.

John, I also spoke to the head shop about the valve covers. They said I should not have any problem with the stock valve covers I have.

I am almost ready to fire this thing up. At this point I just need a fuel inlet adapter for the Edelbrock carb, the new distributor gear, oil prime, and to figure out a way to get water to this thing while its 20 degrees out.

Also, does anyone know what spark plugs and gaps to run for this motor? I've been reading that NGK BR6FS with a .060" gap will work best with vortec heads. Those are the same plugs I ran in the original Merc 260. It also recommended Champion RV8C (I've also heard never to buy a Champion plug) or AC Delco MR43T.