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Discussion Starter · #41 ·
Yes--bummer for sure... I'm thinking these have been this way for a while so the debris is hopefully laying on bottom of the pan or in oil filter...You would never have known by the way it sounded that these were in such bad shape --9 damaged in this same way....a little racket but not too bad. Does anyone know why or how this could have happened... CHEAP STEEL?? Has any one ever seen this happen??
 

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Discussion Starter · #42 ·
After thinking it through, I remember over-reving about a year ago. This must be when the pushrods got messed up. They will be replaced with one-piece rods along with new rockers. In the meantime, moving ahead on replacing the heads. Have it almost cleaned up and ready to install new heads... BTW--After preliminary inspection, the rocker studs look pretty uniform...I will measure them. Even if the problem wasn't that they were pulling out, I am still glad to do this swap. Hopefully this weekend I will get new heads on and torqued down.

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Discussion Starter · #43 ·
QUESTION: It's been about 10 yrs since I've done this... After I clean up cylinder walls, what should I use to lube the walls for startup? Any recommendations? Thanks--Kim
 

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Discussion Starter · #44 · (Edited)
I just coated the cylinder walls with oil and installed passenger side head last night. Wednesday I should be able to get drivers head and hopefully pushrods, rockers, intake... I am using new ARP bolts this time. 10yrs ago I used the originals...

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Discussion Starter · #46 ·
NEW QUESTION! Before I put on the last head I tried one of the old spark plugs to see how they fit...
I have used Autolite #26 since I built engine 10 yrs ago... But they don't seem to fit the same as in the old head... They don't screw in as deep (these are in finger tight) ... Any thoughts?


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Discussion Starter · #47 ·
Haven't had much time but did 2 things this evening. Tested the pushrod length and with stock length 7.8" rods the rockers hit in the middle of the valve stems which is where they should hit if length is correct. I expected this but wanted to test to make sure. I got the new rods and rockers installed... next step to adjust them and then re-install intake...on Wednesday.
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Discussion Starter · #48 ·
Well I got some more done today...Got valves adjusted and intake on. Also, the temp sensor holes in these heads are 3/8" NPT while the old Chevy heads had 1/2" NPT. So I got a 3/8" plug for one side and a 3/8" to 1/2" adaptor today and installed. I will screw in the temp sensor into this adaptor... I think this will keep the temp sender wire further from the header too. Also settled today on NGK TR5 plugs.

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Discussion Starter · #50 ·
Thanks-- Didn't have much rtv excess squeeze out in front under intake...hope I had enough. May get to startup this weekend or certainly by next Wednesday.
 

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Discussion Starter · #51 ·
I realized I forgot to rtv the water ports on both sides of the gaskets so I pulled the intake back off. That's what I get for working on it when I'm tired!

QUESTION: Has anyone ever used block off plates for the EGR ports to keep things cooler under carb? I've used the little plates to make hole smaller that have come with Fel Pro gaskets in the past. Now I have a set of Mahle gaskets with no block offs. Can I just make my own to block off that heat?
 

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After thinking it through, I remember over-reving about a year ago. This must be when the pushrods got messed up. They will be replaced with one-piece rods along with new rockers. In the meantime, moving ahead on replacing the heads. Have it almost cleaned up and ready to install new heads... BTW--After preliminary inspection, the rocker studs look pretty uniform...I will measure them. Even if the problem wasn't that they were pulling out, I am still glad to do this swap. Hopefully this weekend I will get new heads on and torqued down.

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I'm no builder by any stretch but one thing I thought of was maybe the valves weren't adjusted quite right the first time and then then that combined with over reving like you said. I have over reved quite a few times over the years and didn't end up there .
Also what method did you use to determine pushrod length/proper rocker geometry if any ?
Scott foxwell who used to be with Straub technologies has a very good video on setting that up .
But again though....myself not being a builder I'm not sure that this would come into play with this problem you had.
I do know that I used his method recently and it did work out well for me.
According to the higher ups there can only be one optimal pushrod length for a given head and cam .
Course I've also had engines that were NOT set up this way and actually to the tune of .5 inches from being optimal pushrod length and I pounded the snot out of those motors without issue so ....
I just very recently for the first time used this method . Here it is . Maybe it'll be of some use . Using this method i ended up with an 8.6 inch pushrod and believe it or not I had several different guys telling me to just run the stock ones I had which were 7.8


Watch "Push Rod Geometry for Engines" on YouTube
 

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Discussion Starter · #53 ·
Thanks for you thoughts and the Interesting video. Looks like this method works for the roller rockers but not for the stamped rockers like I have. I did do a test which showed my rockers are hitting in middle of valve stems. Also my cam pretty mild...455/465 lift... So hopefully I have them adjusted pretty good got intake re-installed and distributor installed,.the rest should go quicker...
I'm no builder by any stretch but one thing I thought of was maybe the valves weren't adjusted quite right the first time and then then that combined with over reving like you said. I have over reved quite a few times over the years and didn't end up there .
Also what method did you use to determine pushrod length/proper rocker geometry if any ?
Scott foxwell who used to be with Straub technologies has a very good video on setting that up .
But again though....myself not being a builder I'm not sure that this would come into play with this problem you had.
I do know that I used his method recently and it did work out well for me.
According to the higher ups there can only be one optimal pushrod length for a given head and cam .
Course I've also had engines that were NOT set up this way and actually to the tune of .5 inches from being optimal pushrod length and I pounded the snot out of those motors without issue so ....
I just very recently for the first time used this method . Here it is . Maybe it'll be of some use . Using this method i ended up with an 8.6 inch pushrod and believe it or not I had several different guys telling me to just run the stock ones I had which were 7.8


Watch "Push Rod Geometry for Engines" on YouTube
Thanks for the interesting video! Looks like that method works with roller rockers. Mine are stamped steel. I did test mine and found that with the stock pushrods (7.8") the rockers hit the middle of the valve stems which is where they are supposed to touch. My cam is relatively mild .455/.465 Howards cam. I have checked with Howards and also Summit (about height of head) and they both say 7.8 rod length is what is best. So I feel pretty safe about the stock pushrod length.

Made a little more progress over the weekend and got the intake back on (again) and installed the distributor... Hopefully I'll have enough time to fire it up on Wed.
:)
 

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Thanks for you thoughts and the Interesting video. Looks like this method works for the roller rockers but not for the stamped rockers like I have. I did do a test which showed my rockers are hitting in middle of valve stems. Also my cam pretty mild...455/465 lift... So hopefully I have them adjusted pretty good got intake re-installed and distributor installed,.the rest should go quicker...


Thanks for the interesting video! Looks like that method works with roller rockers. Mine are stamped steel. I did test mine and found that with the stock pushrods (7.8") the rockers hit the middle of the valve stems which is where they are supposed to touch. My cam is relatively mild .455/.465 Howards cam. I have checked with Howards and also Summit (about height of head) and they both say 7.8 rod length is what is best. So I feel pretty safe about the stock pushrod length.

Made a little more progress over the weekend and got the intake back on (again) and installed the distributor... Hopefully I'll have enough time to fire it up on Wed.
:)
Roller rockers or not proper geometry is proper geometry and there's only one length that's optimal in any pushrod engine .
Will it run "ok" even with a pushrod that's being used is a half an inch too long or short ?
Yes
Is it right ? No
And BTW summits video on setting that up is 100 percent certifiably retarded lol
That guy is f^*^$'ing CLULESS hahaha
Its your motor man. Call the shot
 

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Discussion Starter · #55 ·
Got quite a bit done today but things took a bit longer than I thought (as usual :)). Because these heads have a 3/8" for my water temp gauge, I needed to use an adaptor from 3/8" to 1/2". Adaptor is pretty big so I needed to grind a slot in my header to make room for the adaptor so the header bolts would line up. I was hoping the adaptor would get temp sensor wire further away from header but..not very much.... Anyway, getting closer---should fire it up this weekend...

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Discussion Starter · #56 ·
Almost there but not tonight! I have a really good set of spark plug wires that I don't want to burn on the headers so I ordered 8 new heat shields for the boots. Wed will be startup day. One thing I notice about these heads is they are a slightly higher casting at the top which puts the valve cover up about 1/4"... pretty much touching my ac delete box. I may need to change the shape of that to provide a little clearance. we'll see...



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Discussion Starter · #57 ·
She fired up almost immediately! Runs GREAT! --noticeably much smoother on the power curve from high load/low RPM on up. Throttle response is better. Also easier to spin the tire! This is the best this car has run in 10 years! :). Low end is where I notice the biggest difference so far but we will see as I drive it more.

Also valve train noise is minimal just like I have always thought it should be but could never quite get there. I adjusted 1/2 turn past zero lash. We will see how all this continues to work but looks like a bullseye at this point. THANKS to everyone who had input on this head swap.!
 

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Discussion Starter · #59 · (Edited)
Thanks but It didn't last long! It changed overnight. I took it to work Thursday and it starts off from a stop sign and then totally bogs...then goes and pulls strong... Sometimes it will actually stall if I put it to the floor in neutral... Not sure what to check first but since it changed overnight maybe a vacuum leak on intake? About 6 wks ago I rebuilt carb and it was working great... I know I plan to re-torque intake... ANY SUGGESTIONS?
 

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Discussion Starter · #60 ·
Well... I had some time this evening to check this out and discovered that the initial timing changed from 10 degrees advanced to about 10 degrees retarded!! I guess I hadn't tightened the distributor down enough and once the engine had cooled down it moved when I started it the next morning. Anyway runs great again! :) I'm still going to re-torque the intake.

I was basically happy with the performance of the old heads...I didn't care about having more power because they were decent BUT there is noticeably more power...winds up quicker, and more easily spins the tire (open rear) which means I need to be a little more careful... In general less small hesitations --smoother power curve. Deeper exhaust sound too.:cool:

Thanks again everybody for your input!
 
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