#41  
Old 09-13-2021, 10:57 AM
Chris-Austria Chris-Austria is offline
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Originally Posted by Skip Fix View Post
Yes bring cylinder to TDC Depending on deck height and valve notches you may or may not has to use air or the rope trick, but one or the other helps.
If on TDC, is there still a chance the valve will fall down? Deck height is stock and valve notches are maybe a little bigger than standard because I had to get the compression down a little with 462cui and 72cc heads. Still they are not massive... I think the pistons have -12cc or something like that.

The rope seems to be a good idea, since air pressure would force the piston down.

  #42  
Old 09-13-2021, 11:30 AM
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Even with a dished piston, but with a 72 CC chamber size the valve should not drop out at TDC.

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  #43  
Old 09-13-2021, 12:54 PM
Chris-Austria Chris-Austria is offline
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Thats good news. The pistons are -15cc.
The only number I have not is the deck clearance, but it should be around .020 since the block was stock and we didn't zero deck it. So I should be around 10.4:1 and 10.6:1 CR. (10.24-6.80-2.125-1.295 = 0.02 deck clearance)

Would be pretty bad if a valve drops since I only bought the spring compressor tool to avoid removing the heads.

  #44  
Old 09-14-2021, 09:15 AM
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As Steve said generally they will not drop in most cases.

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1978 Trans Am original owner 10.99 @ 124 pump gas 455 E heads, NO Bird ever!
1981 Black SE Trans Am stockish 6X 400ci, turbo 301 on a stand
1965 GTO 4 barrel 3 speed project
2004 GTO Pulse Red stock motor computer tune 13.43@103.4
1964 Impala SS 409/470ci 600 HP stroker project
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  #45  
Old 09-14-2021, 09:40 AM
78w72 78w72 is offline
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Quote:
Originally Posted by Chris-Austria View Post
If on TDC, is there still a chance the valve will fall down? Deck height is stock and valve notches are maybe a little bigger than standard because I had to get the compression down a little with 462cui and 72cc heads. Still they are not massive... I think the pistons have -12cc or something like that.

The rope seems to be a good idea, since air pressure would force the piston down.
the air psi needed to hold the vale up will definitely not push the piston down. the main benefit to using air is it holds the valve all the way up nice & tight & makes adding the locks & new spring while using the spring compressor tool much easier.

im sure the rope works ok but the air is quick & easy & wont even budge the piston.

  #46  
Old 09-14-2021, 10:29 AM
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the air psi needed to hold the vale up will definitely not push the piston down. the main benefit to using air is it holds the valve all the way up nice & tight & makes adding the locks & new spring while using the spring compressor tool much easier.

I agree. Sometimes the seal holds it good sometimes it slips down getting the locks back on is a pain.

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1978 Trans Am original owner 10.99 @ 124 pump gas 455 E heads, NO Bird ever!
1981 Black SE Trans Am stockish 6X 400ci, turbo 301 on a stand
1965 GTO 4 barrel 3 speed project
2004 GTO Pulse Red stock motor computer tune 13.43@103.4
1964 Impala SS 409/470ci 600 HP stroker project
1979 Camaro IAII Edelbrock head 500" 695 HP 10.33@132 3595lbs
  #47  
Old 09-14-2021, 10:51 AM
Chris-Austria Chris-Austria is offline
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Sounds like I will have a lot of fun changing the valve springs
But I'll use compressed air and get the pistons on top just in case something happens.
Hope I can feel the difference when it's all done

  #48  
Old 09-14-2021, 12:39 PM
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I changed from SFT to SR springs in the car. 72cc E heads. Did get harder to rotate as more cylinders got the stiffer springs!

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1978 Trans Am original owner 10.99 @ 124 pump gas 455 E heads, NO Bird ever!
1981 Black SE Trans Am stockish 6X 400ci, turbo 301 on a stand
1965 GTO 4 barrel 3 speed project
2004 GTO Pulse Red stock motor computer tune 13.43@103.4
1964 Impala SS 409/470ci 600 HP stroker project
1979 Camaro IAII Edelbrock head 500" 695 HP 10.33@132 3595lbs
  #49  
Old 09-14-2021, 02:12 PM
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You may not notice any difference until 20K miles down the road when the springs are still doing there job just fine!

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Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs!
And he was not talking about 1/8 or 1/4 mile ETs!

1) 1940s 100% silver 4 cup tea server set.

Two dry rotted 14 x 10 Micky Thompson slicks.

1) un-mailed in gift coupon from a 1972 box of corn flakes.
Two pairs of brown leather flip flops, never seen more then 2 mph.

Education is what your left with once you forget things!
  #50  
Old 10-12-2021, 06:17 PM
Chris-Austria Chris-Austria is offline
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So I did it... it wasn't just a cam and spring change in the end... I did:

- changed the xe276hr to the OF cam from Butler
- replaced valve springs (with Edelbrock 5845.) using the Proform 66784 tool.. wasn't too hard with engine in the car
- replaced valve seals
- gasket matched the RPM intake
- build new wires and connectors for the EFI

Because of bad weather I couldn't do much testing, but it clearly feels stronger and it runs really nice...idling at 800rpm without any issue and no problem with vacuum.

If anyone with a 455 is wondering, if the old faithfull cam is too big... don't worry... I'm pretty sure a tighter LSA would also be streetable.. mine has 236/242/114.

  #51  
Old 10-12-2021, 06:54 PM
ta man ta man is offline
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Quote:
Originally Posted by Chris-Austria View Post
So I did it... it wasn't just a cam and spring change in the end... I did:

- changed the xe276hr to the OF cam from Butler
- replaced valve springs (with Edelbrock 5845.) using the Proform 66784 tool.. wasn't too hard with engine in the car
- replaced valve seals
- gasket matched the RPM intake
- build new wires and connectors for the EFI

Because of bad weather I couldn't do much testing, but it clearly feels stronger and it runs really nice...idling at 800rpm without any issue and no problem with vacuum.

If anyone with a 455 is wondering, if the old faithfull cam is too big... don't worry... I'm pretty sure a tighter LSA would also be streetable.. mine has 236/242/114.
What is the valve lift on that cam?

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  #52  
Old 10-12-2021, 07:14 PM
wbnapier wbnapier is offline
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I used that pro-form valve spring compressor and didn't like it. The fork angle is not correct for a Pontiac head. It can work, but was dicey on some.

If I had it to do over, I would get a LSM one or weld something to the fork to make it flat to the spring.

Here are the LSM ones:

https://lsmproducts.com/collections/...ng-compressors

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  #53  
Old 10-13-2021, 07:30 AM
Chris-Austria Chris-Austria is offline
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Quote:
Originally Posted by ta man View Post
What is the valve lift on that cam?
236/242, .521/.540, 114 LS

  #54  
Old 10-13-2021, 07:32 AM
Chris-Austria Chris-Austria is offline
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Quote:
Originally Posted by wbnapier View Post
I used that pro-form valve spring compressor and didn't like it. The fork angle is not correct for a Pontiac head. It can work, but was dicey on some.

If I had it to do over, I would get a LSM one or weld something to the fork to make it flat to the spring.

Here are the LSM ones:

https://lsmproducts.com/collections/...ng-compressors
I forgot to mention... I had to bend the fork... took me 30 seconds max If the fork is flat, it works really well. And it locks when the valve spring is compressed... which is pretty comfortable.

  #55  
Old 10-13-2021, 09:23 AM
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Glad it went well!

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1978 Trans Am original owner 10.99 @ 124 pump gas 455 E heads, NO Bird ever!
1981 Black SE Trans Am stockish 6X 400ci, turbo 301 on a stand
1965 GTO 4 barrel 3 speed project
2004 GTO Pulse Red stock motor computer tune 13.43@103.4
1964 Impala SS 409/470ci 600 HP stroker project
1979 Camaro IAII Edelbrock head 500" 695 HP 10.33@132 3595lbs
  #56  
Old 10-13-2021, 10:31 AM
Chris-Austria Chris-Austria is offline
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Quote:
Originally Posted by Skip Fix View Post
Glad it went well!
Me too, wasn't so sure when I started but in the end my biggest problem is a thermostat housing which will not seal. I found out the mounting surface is bent... after trying the O ring = leaking, then a paper gasket = leaking and finally silicone with paper gasket = still leaking.

It was also necessary to remove the support bracket for the horns, to have enough space to remove the cam... but after that (3 or 4 bolts) it was very easy to get it out and the new one in.

Sadly some water ran into the oil pan after removing the timing cover... but I had to change the oil anyway.

  #57  
Old 10-13-2021, 11:35 AM
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If the O ring type does not seal up then I would say your your two hold down bolts are too long and bottoming out.

Add a washer or two to each.

I have leveled off a warped housing by sanding it in a figure 8 pattern on soapy water lubed up wet or dry 180 grit sand paper.
It takes a while, but it works if the housing is not warped too much.

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Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs!
And he was not talking about 1/8 or 1/4 mile ETs!

1) 1940s 100% silver 4 cup tea server set.

Two dry rotted 14 x 10 Micky Thompson slicks.

1) un-mailed in gift coupon from a 1972 box of corn flakes.
Two pairs of brown leather flip flops, never seen more then 2 mph.

Education is what your left with once you forget things!
  #58  
Old 10-13-2021, 11:37 AM
ta man ta man is offline
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Quote:
Originally Posted by Chris-Austria View Post
236/242, .521/.540, 114 LS
That is a mild lift compared to the real OF cam offered by SD. Butler doesn't call this the OF cam do they?

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308 gears best et 10.76/125.64/1.5471
  #59  
Old 10-13-2021, 12:07 PM
Steve C. Steve C. is offline
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Butler uses Comp XE hydraulic roller lobes. In the linked cam here the only similarity to Dave Bisschop's Old Faithful cam is the same 236 degrees intake duration and the same 112 LSA.

https://butlerperformance.com/i-2503...tegory:1272239


.

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  #60  
Old 10-13-2021, 08:36 PM
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Quote:
Originally Posted by ta man View Post
That is a mild lift compared to the real OF cam offered by SD.
Yup,
Here are valve lift traces for both (1.65 rockers) using a few hundred data points from Comp. Real OF intake is the lighter.

That said, the smaller lobe will often run very low 11s with a well built 455 combo / 300 CFM head. Using 110 LSA if people think it matters.


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