[C1] Tail Light Thursday and Rookie Mistake
02-23-2017, 04:47 PM
#1
Tail Light Thursday and Rookie Mistake
Picture is my 1962 Corvette ready for paint.. I had the car painted about 12 years ago when I had the body off the frame. Was never happy with the paint job. I could see all the seams in the car and decided to redo it my self.
Now for the rookie mistake. A year ago, (with help from members) I decided to install the LT-1 cam into the 327 340HP motor. The other day I decided to fire up the car for the first time in 13 years. The result was not good. Motor didn't run well at all.
First of all. I had several issues all minor, that I have fixed. Felt pretty good since I had gone thru a complete frame off restoration. Now on to the motor. After a day of trying to figure out what was going on, well.... Let me just say, this statement I found on the forum captures my rookie mistake...
"Jim, when you're at #1 TDC, both valves for #1 cylinder will be closed; the other TDC position will have both valves for #6 cylinder closed. As Lars indicated, when the cam and crank sprockets are "dot-to-dot" (crank dot at 12 o'clock, cam dot at 6 o'clock), the engine is at #6 TDC, not #1 TDC."
Now you know my rookie mistake..
PS. Any recommendations for lash settings would be appreciated. I've read, use the card specs, and I have read use 24/30.
Mark
Now for the rookie mistake. A year ago, (with help from members) I decided to install the LT-1 cam into the 327 340HP motor. The other day I decided to fire up the car for the first time in 13 years. The result was not good. Motor didn't run well at all.
First of all. I had several issues all minor, that I have fixed. Felt pretty good since I had gone thru a complete frame off restoration. Now on to the motor. After a day of trying to figure out what was going on, well.... Let me just say, this statement I found on the forum captures my rookie mistake...
"Jim, when you're at #1 TDC, both valves for #1 cylinder will be closed; the other TDC position will have both valves for #6 cylinder closed. As Lars indicated, when the cam and crank sprockets are "dot-to-dot" (crank dot at 12 o'clock, cam dot at 6 o'clock), the engine is at #6 TDC, not #1 TDC."
Now you know my rookie mistake..
PS. Any recommendations for lash settings would be appreciated. I've read, use the card specs, and I have read use 24/30.
Mark
02-23-2017, 09:32 PM
#2
Burning Brakes
Why are your rear spring shackles hanging down so low ? I don't think you are supposed to see them, are they upside down ?
As far as the valve adjustment I got caught the same way. With a LT1 cam I believe you CAN'T use the TDC for #1 to adjust half the valves and TDC for #6 to do the other half. AFAIK the valve ramps are too long and the valves have to be adjusted individually. If I am out in right field someone will set us straight.
As far as the valve adjustment I got caught the same way. With a LT1 cam I believe you CAN'T use the TDC for #1 to adjust half the valves and TDC for #6 to do the other half. AFAIK the valve ramps are too long and the valves have to be adjusted individually. If I am out in right field someone will set us straight.
02-23-2017, 10:31 PM
#3
Safety Car
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I have a real-deal LT-1 block in my '61. It's a short block that was purchased at the parts counter of the local Chevy dealer in 1971 by my father. I still have the receipt. It was $575!
On the receipt is hand-written "lash .024/.030". I don't know where that info came from, likely the guy at the parts counter..... but that what I run, and it seems to do fine.
I know this is a semi-religious topic over in C3... Maybe try a post over there?
Regarding the adjustment process.. I use the "8 stop 90 degree" method recommended by JohnZ and others.. They even mentioned the LT-1 cam as needing this procedure due to the long exhaust ramp.
Edit: Here is the adjustment procedure: https://www.corvetteforum.com/forums...post1561437667
On the receipt is hand-written "lash .024/.030". I don't know where that info came from, likely the guy at the parts counter..... but that what I run, and it seems to do fine.
I know this is a semi-religious topic over in C3... Maybe try a post over there?
Regarding the adjustment process.. I use the "8 stop 90 degree" method recommended by JohnZ and others.. They even mentioned the LT-1 cam as needing this procedure due to the long exhaust ramp.
Edit: Here is the adjustment procedure: https://www.corvetteforum.com/forums...post1561437667
Last edited by SDVette; 02-23-2017 at 11:12 PM.
02-24-2017, 11:35 AM
#6
Why are your rear spring shackles hanging down so low ? I don't think you are supposed to see them, are they upside down ?
As far as the valve adjustment I got caught the same way. With a LT1 cam I believe you CAN'T use the TDC for #1 to adjust half the valves and TDC for #6 to do the other half. AFAIK the valve ramps are too long and the valves have to be adjusted individually. If I am out in right field someone will set us straight.
As far as the valve adjustment I got caught the same way. With a LT1 cam I believe you CAN'T use the TDC for #1 to adjust half the valves and TDC for #6 to do the other half. AFAIK the valve ramps are too long and the valves have to be adjusted individually. If I am out in right field someone will set us straight.
Yes, in regards to the spring shackles. They are on my list to fix. When I build out the rolling chassis I placed the leaf springs below the rear frame cross member vs above. I noticed it was wrong when I put the body back in the car and saw them sticking out below the body.
As for the engine issue. I believe what I did is place my distributor with rotor facing #1. But with the cam and crank gears aligned dot to dot.. I believe that is 6 firing.
Thanks,
Mark
02-24-2017, 11:41 AM
#8
I have a real-deal LT-1 block in my '61. It's a short block that was purchased at the parts counter of the local Chevy dealer in 1971 by my father. I still have the receipt. It was $575!
On the receipt is hand-written "lash .024/.030". I don't know where that info came from, likely the guy at the parts counter..... but that what I run, and it seems to do fine.
I know this is a semi-religious topic over in C3... Maybe try a post over there?
Regarding the adjustment process.. I use the "8 stop 90 degree" method recommended by JohnZ and others.. They even mentioned the LT-1 cam as needing this procedure due to the long exhaust ramp.
Edit: Here is the adjustment procedure: https://www.corvetteforum.com/forums...post1561437667
On the receipt is hand-written "lash .024/.030". I don't know where that info came from, likely the guy at the parts counter..... but that what I run, and it seems to do fine.
I know this is a semi-religious topic over in C3... Maybe try a post over there?
Regarding the adjustment process.. I use the "8 stop 90 degree" method recommended by JohnZ and others.. They even mentioned the LT-1 cam as needing this procedure due to the long exhaust ramp.
Edit: Here is the adjustment procedure: https://www.corvetteforum.com/forums...post1561437667
I'll checked that procedure. That will help me out a lot.
Thanks,
Mark
02-24-2017, 02:27 PM
#9
Safety Car
Member Since: Jan 2000
Location: Poway CA
Posts: 4,844
Received 1,295 Likes
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2023 C1 of the Year Finalist - Unmodified
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I'm not an expert on this, but I believe the lash setting varies depending on head type (Iron vs. Aluminum), and may be the reason for the different data out there. The original LT-1 had aluminum heads I believe... While I'm running Iron heads on the LT-1 block.
02-24-2017, 05:10 PM
#10
Why are your rear spring shackles hanging down so low ? I don't think you are supposed to see them, are they upside down ?
As far as the valve adjustment I got caught the same way. With a LT1 cam I believe you CAN'T use the TDC for #1 to adjust half the valves and TDC for #6 to do the other half. AFAIK the valve ramps are too long and the valves have to be adjusted individually. If I am out in right field someone will set us straight.
As far as the valve adjustment I got caught the same way. With a LT1 cam I believe you CAN'T use the TDC for #1 to adjust half the valves and TDC for #6 to do the other half. AFAIK the valve ramps are too long and the valves have to be adjusted individually. If I am out in right field someone will set us straight.
You shamed me into fixing leaf springs.. Thanks for the motivation!!!LoL!!
Mark
02-25-2017, 07:17 PM
#12
Picture is my 1962 Corvette ready for paint.. I had the car painted about 12 years ago when I had the body off the frame. Was never happy with the paint job. I could see all the seams in the car and decided to redo it my self.
Now for the rookie mistake. A year ago, (with help from members) I decided to install the LT-1 cam into the 327 340HP motor. The other day I decided to fire up the car for the first time in 13 years. The result was not good. Motor didn't run well at all.
First of all. I had several issues all minor, that I have fixed. Felt pretty good since I had gone thru a complete frame off restoration. Now on to the motor. After a day of trying to figure out what was going on, well.... Let me just say, this statement I found on the forum captures my rookie mistake...
"Jim, when you're at #1 TDC, both valves for #1 cylinder will be closed; the other TDC position will have both valves for #6 cylinder closed. As Lars indicated, when the cam and crank sprockets are "dot-to-dot" (crank dot at 12 o'clock, cam dot at 6 o'clock), the engine is at #6 TDC, not #1 TDC."
Now you know my rookie mistake..
PS. Any recommendations for lash settings would be appreciated. I've read, use the card specs, and I have read use 24/30.
Mark
Now for the rookie mistake. A year ago, (with help from members) I decided to install the LT-1 cam into the 327 340HP motor. The other day I decided to fire up the car for the first time in 13 years. The result was not good. Motor didn't run well at all.
First of all. I had several issues all minor, that I have fixed. Felt pretty good since I had gone thru a complete frame off restoration. Now on to the motor. After a day of trying to figure out what was going on, well.... Let me just say, this statement I found on the forum captures my rookie mistake...
"Jim, when you're at #1 TDC, both valves for #1 cylinder will be closed; the other TDC position will have both valves for #6 cylinder closed. As Lars indicated, when the cam and crank sprockets are "dot-to-dot" (crank dot at 12 o'clock, cam dot at 6 o'clock), the engine is at #6 TDC, not #1 TDC."
Now you know my rookie mistake..
PS. Any recommendations for lash settings would be appreciated. I've read, use the card specs, and I have read use 24/30.
Mark
Ok, so today I check to see if distributor was installed correctly (#1 on compression stroke., and it was. So that was not the reason for my engine not running... I thought that I might have installed it incorrectly after installing my new Speed Pro LT-1 cam.
So then I rechecked my valve lash settings. I found the intakes to be very tight and the exhaust to be very loose.. I guess this would cause the issue I had. Actually, the engine did feel like it was trying to run in wet cement. I originally had set them to the card specs. I just finished resetting them to .024 / .030. Went aground three times to check myself. (since I apparently failed the first time). Tomorrow I'll get the plugs and stuff back on and see if that was the issue..
Hope it is,
Mark