Planning a new 383 build that is now going to be a 400

busterrm said:
Okay I just read that link, So I am okay as long as I have .08 intake and .10 on exhaust and .20 radial clearance? The cam is already set at where its going to run when the engine is assembled. Do I need to do a clearance check on all 8 cylinders or just the #1?
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in theory if they are all machined the same checking one should be ok, in reality the chances are excellent that clearances vary between cylinders and checking them all, at least with some clay placed on the pistons in the valve notches and rotating the engine over several times and a quick visual check, is a better route to take
 
Will be ordering the Rockers this friday, then I will do the piston to valve clearance check. Then off to be balanced.
 
Okay I have a few questions! Is it okay to do the piston to valve clearance without a gasket? I know the thickness I am going to be using, just add that thickness to the clearances I get. Would it be better to buy the gaskets, so there is no question at all? I am talking about the head gaskets!
 

Wow you do get online once in awhile, been far and few between lately!!!

Seems like it would be very acceptable to me. If the clearance turn out to be close, then you might want to recheck with the gasket installed.

I calculated my clearance to be .133/.160 (Intake/Exhaust) and my check with clay seems to bear out my numbers. I have lift number of .562/.567.

It is completely possible with lower lift numbers, but have closer PTVC, proceed at your own risk!!!

But if you are right on the limit, then I would be inclined to check with a gasket.



 

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Indycars said:

Wow you do get online once in awhile, been far and few between lately!!!

Seems like it would be very acceptable to me. If the clearance turn out to be close, then you might want to recheck with the gasket installed.

I calculated my clearance to be .133/.160 (Intake/Exhaust) and my check with clay seems to bear out my numbers. I have lift number of .562/.567.

It is completely possible with lower lift numbers, but have closer PTVC, proceed at your own risk!!!

But if you are right on the limit, then I would be inclined to check with a gasket.
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Well, mine is going to be real close to your same lift. Mine will be .563 on both valves. So I am expecting it to be similar, maybe not exactly like yours, but should be close. I think the difference will be that I am using a thinner gasket than you, yours has a shorter deck clearance also. So I am thinking they will be similar, there might be another difference with your longer rods.
Oh yeah, I am online every night just don't always post. Just watching and doing a lot of reading and research. This engine is going to have a lot of my blood, sweat and tears in it and I want it right the first time.
Rockers should be here sometime this week, and I am getting ready to do the PTVC checks, I want the rotating ass in the machine shop ASAP.
I guess I am tired of not doing anything, this thing has sit for the last month. Delays, delays, delays, work, work, work!!
 
Wow, there was no delay! My Rocker arms are here, and they are pretty!
 

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I miss working on chevy engine, take your time because as usual it will be reliable because of all the advises from the guy in this forum, so you probably will not have to touch it again once its break/in and setup to your need. :twisted:

Also, am not sure but i think we see your paypal info in the paper in the picture.
 

Mathd, I think you might be right so I went ahead and blurred that info.

I kinda like those rocker also!!! One thing you will want to be aware of is
the recess in pivot. It might have messed up some my measurements
until I realized what was happening.



 

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mathd said:
I miss working on chevy engine, take your time because as usual it will be reliable because of all the advises from the guy in this forum, so you probably will not have to touch it again once its break/in and setup to your need. :twisted:

Also, am not sure but i think we see your paypal info in the paper in the picture.
Click to expand...
wholie molie I never thought about that Mathd, crap I just tossed then on my pc desk and shot the picture. Thanks buddy and you too Rick!
 
Okay, with the rockers here I am going do the PTVC this week. also going to do the pushrod checking for length also. I bought 4 test bolts to use in the process, just cheapy ones. I am going use two 7.4 pushrods for a LS1 to do the PTVC checking. I am going to use old fashioned Playdough to make sure they are all symetrical. Okay, Okay, I never grew up, yes I still like playing with playdough. Hahahahahahahahahaha! Will the length of the LS1 pushrods be okay for the PTVC checks?
 
Too many variables to know exact pushrod length required for your exact valvetrain layout Bob.
Is the 7.400 inch end to end pushrods what you determined to be correct and gives a centered roller rocker arm patern on valvestem tip marked with a blue Sharpie Marker ?
IF so it would be ok to do your clay checks.
I think you have an adjustable pushrod length checker in your toolbox too.
 





play doughs a bit springy, model clays a bit more precise, and a light spray of WD40 tends to reduce any tendency to stick to parts being checked for clearances
 
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busterrm said:
Okay, with the rockers here I am going do the PTVC this week. also going to do the pushrod checking for length also.
(1) I bought 4 test bolts to use in the process, just cheapy ones.
(2) I am going use two 7.4 pushrods for a LS1 to do the PTVC checking.
(3) I am going to use old fashioned Playdough to make sure they are all symetrical. Okay, Okay, I never grew up, yes I still like playing with playdough. Hahahahahahahahahaha! Will the length of the LS1 pushrods be okay for the PTVC checks?
Click to expand...

Guys ..... I think he is asking if he can check the "Valve To Piston Clearance" (PTVC) with 7.4" pushrod from the LS1, since he doesn't have the exact ones he will be using yet.

(1) You lost me here, what are you going to use the 4 test bolts for???

(2) I would first check to see where it rides on the valve stem. If it's close to the center, then it should be OK for checking the PTVC. But if it close to the minimum clearances, then recheck with the purchased pushrods. Also make sure the END of the pushrod is of the same design as the rockers are made for.

(3) Play Dough, not just for little kids, but BIG kids too !!! :D

Do you have light checking springs, the adjustable pushrods won't handle the dual valve springs you have.

 
Indycars said:
busterrm said:
Okay, with the rockers here I am going do the PTVC this week. also going to do the pushrod checking for length also.
(1) I bought 4 test bolts to use in the process, just cheapy ones.
(2) I am going use two 7.4 pushrods for a LS1 to do the PTVC checking.
(3) I am going to use old fashioned Playdough to make sure they are all symetrical. Okay, Okay, I never grew up, yes I still like playing with playdough. Hahahahahahahahahaha! Will the length of the LS1 pushrods be okay for the PTVC checks?
Click to expand...

Guys ..... I think he is asking if he can check the "Valve To Piston Clearance" (PTVC) with 7.4" pushrod from the LS1, since he doesn't have the exact ones he will be using yet.

(1) You lost me here, what are you going to use the 4 test bolts for???

(2) I would first check to see where it rides on the valve stem. If it's close to the center, then it should be OK for checking the PTVC. But if it close to the minimum clearances, then recheck with the purchased pushrods. Also make sure the END of the pushrod is of the same design as the rockers are made for.

(3) Play Dough, not just for little kids, but BIG kids too !!! :D

Do you have light checking springs, the adjustable pushrods won't handle the dual valve springs you have.
Click to expand...
Exactly Rick! I don't have the pushrods yet, I might have to special order them. I already did the check with the adjustable pushrod. Exact length needed is 7.425 (with gasket 7.44)the LS1 pushrods are 7.406. I have two adjustable pushrods. One for 6.9 - 7.4, one for 7.4- 7.9. I used that second and it seemed to hold up to the spring pressures I have. All the way in was just a slight bit too short, so I turned it out a half turn. Locked the jam nut and and it was the nice thin line on the valve stem centered. Took it to work and had friend check it. All the valves gave the slim centered line on the valve stem. There was some variance, but not much. The ends are why I chose the pushrod I chose, I took one rocker with me to the parts store to make sure. I will probably buy 7.45 pushrods.
The 4 test bolts are to secure the heads, I don't have studs yet either. So I am using some cheapie bolts that are same size at the head bolts in length, don' t worry I have the correct hardened washers to protect the heads.
 
Rick, I ran the exact same Comp Cams 987-16 valvesprings Busterm is using.
Perfect fit on a 1970 Pontiac Ram Air 4 head.
Used adjustable pushrods during mockup clearance checks.
Daul 987 springs intact.
No issues of adjustable pushrod bending.
 
Reread Bob & Rick.
I agree.
Should be ok checking with 7.400 pushrods.
Wait to see if Grumpy agrees also.
 
Did not get the chance to do the PTVC checks this week. I will have to do it after Rick and I finish the heads this weekend. Been a bad week, we lost a buddy at work to cancer, tuff fella he worked 55 hours a week up to a week before he passed away.
 
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