CK5
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64 Vette….Rebuild 2.0
- Thread starter 76zimmer
- Start date
I like the new ones. Then again I like my new Silverado.
New personal bests for the car on a few different passes.
dropped ET for 60’ to 1.89, 1/8 to 7.93/91 and 1/4 to 12.24/115
Pretty happy with the car right now.
All passes but the last one were launched at 2000 on the foot brake. Spun 2/4 passes, so dropped to 1500 launch. Worked quite well. 36* timing.
I have some plugs to dissect when I get them out of the car.
one plug was a fresh plug w minimal idle time, and shutdown after a pass, then pulled, so Im anxious to read that one. The other set has had more than 25 runs plus some street time as well, but all the plugs were on race gas.
car #114 on the slips….
dropped ET for 60’ to 1.89, 1/8 to 7.93/91 and 1/4 to 12.24/115
Pretty happy with the car right now.
All passes but the last one were launched at 2000 on the foot brake. Spun 2/4 passes, so dropped to 1500 launch. Worked quite well. 36* timing.
I have some plugs to dissect when I get them out of the car.
one plug was a fresh plug w minimal idle time, and shutdown after a pass, then pulled, so Im anxious to read that one. The other set has had more than 25 runs plus some street time as well, but all the plugs were on race gas.
car #114 on the slips….
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Nice! Good runs Dave!
You just need some sticky tires to get into the 11s Zim, your MPH shows you got the ponies to do it.
You just need some sticky tires to get into the 11s Zim, your MPH shows you got the ponies to do it.
4 pt. Roll bar, 4 pt belts, Tires, wheels, shocks, springs, 31 spline axles, offset trailing arms, convertor, Engine refresh, trans refresh. Its a money pit!
pretty happy with it right now, but I definitely want to do the axle upgrades, and get some better belts in it, hence the roll bar. Should probably check the bearings, its been together for 13 years now, with a lot of full throttle action.
pretty happy with it right now, but I definitely want to do the axle upgrades, and get some better belts in it, hence the roll bar. Should probably check the bearings, its been together for 13 years now, with a lot of full throttle action.
First 2 pics are a new plug…installed, driven to staging lanes (part throttle), shut off and pushed until ready for a burnout, made burnout and pass, then killed it right after the line.
looks like timing is too far advanced?
not sure about mixture on that single pass, maybe lean?
the rest of the pics have 8 passes on them, including when it was sucking oil from the lifter valley and blowing a decent blue cloud on a few of those passes.
timing maybe advanced to far, mixture looks good?
looks like timing is too far advanced?
not sure about mixture on that single pass, maybe lean?
the rest of the pics have 8 passes on them, including when it was sucking oil from the lifter valley and blowing a decent blue cloud on a few of those passes.
timing maybe advanced to far, mixture looks good?
Excellent videos. So cool actually seeing a Vette from that generation going down a track. Very cool.
You must be running the 1/4 mile at a somewhat high RPM to be doing 115-MPH a little over 12-seconds. My 1970 SS Chevelle was running about 111-MPH at just barely under 12-seconds (11.98) at about 4750-RPM. I did not want to run it much higher that, and blow up a $5000 engine (1982 prices for a top of the line engine).
I have driven my friends 1965 Stingray 396, with 4-speed trans, a few times. I am the one that sold him a 396 out of a 1968 Chevy C20 Suburban back in about 1981 that is in his Stingray to this day. Those things handle like a truck. I cannot imagine driving one of those things at 115 MPH.
I have driven my friends 1965 Stingray 396, with 4-speed trans, a few times. I am the one that sold him a 396 out of a 1968 Chevy C20 Suburban back in about 1981 that is in his Stingray to this day. Those things handle like a truck. I cannot imagine driving one of those things at 115 MPH.
Just needs a touch of air dam up front
Took a boroscope video of cylinders 8 and 6. Looks like some carbon buildup, and some vertical scratches at the top of the cylinders.
if I do anymore, I’ll make sure the piston is down in the hole .
Cylinder 8…
cylinder 6…
if I do anymore, I’ll make sure the piston is down in the hole .
Cylinder 8…
cylinder 6…
Dave on motor only I don't use the ground strap as a timing indicator, I just use the MPH. Use the timing it wants for the best MPH, but no more. If it makes the same MPH at 36 and 38 for example, then use the 36.
Once you start adding power adders like boost or nitrous then I would look at the ground strap and the MPH.
Once you start adding power adders like boost or nitrous then I would look at the ground strap and the MPH.
So timing remained at 36* for all of these passes. 113-115. In the past more timing hasnt gotten me any more mph.
whats your take on the plugs shown, and opinion on the verticle scratch on the cylinders….looks like piston scuff as it goes all the wayto the top of cylinder. Worth a teardown for further inspection?
whats your take on the plugs shown, and opinion on the verticle scratch on the cylinders….looks like piston scuff as it goes all the wayto the top of cylinder. Worth a teardown for further inspection?
Did it slow down at 34 degrees of timing? I would guess it did? If so I would leave it at 36. I was running my old 388 locked at 38, because it didn't pick up any more at 40 degrees. Sounds like yours might like 36.
I'd do a compression and leakdown before I would tear it down. If the compression and leakdown are fine, then don't worry about it. If the scratches are deep enough to matter they should show up on the leakdown test. Just make sure to do the leakdown at TDC with the valves closed of course.
As for the plugs, they look pretty good, but on an N/A motor with your compression and pump gas, I again would go on testing. Does it want more fuel? Did you try more fuel? I'd increase the jet size and see if it likes it down the strip. Based on your statement that it bogged down when the temp was lower I would guess it might want more fuel. If the oil temp is warm and the coolant is at least 140 it shouldn't bog down, it should run better with a cooler engine temp.
When you get to boosted engines and nitrous the window is smaller. On an NA motor you have a larger window to hit without damage. And If it goes faster with more fuel and the plugs don't foul I'd run more fuel even if the plugs look a little rich. The only way to know that is try it. Jet up 2 - 4 jet sizes on both ends and see if it likes it. If you are running a power valve in the primary only keep the split at least 10 I would say, maybe even more if it doesn't like the large primary jets around idle and cruising.
Its all a compromise, if it goes faster with larger jets but fouls plugs on the street than increase the split or start playing with larger PVCR and high flow power valves, tuning the bleeds etc.
Or get EFI, ha ha
I guess what I am saying on a low compression NA motor, just test and see what it likes. The plugs are secondary in my opinion, if it wants it let it have it, the car will tell you it doesn't like it before it should hurt anything, if its stops picking up then back off to where you were. If it goes slower to the opposite. Of course if you ever get detonation then back it off to the last known good tune (and fuel) before making another run.
Now if you were super high RPM, very high compression, or on nitrous or boost the window is smaller and stuff can go boom without much warning, then it's more important to look at the plugs before making changes, because if you make the wrong change, then you might have holes in your pistons.
Disclaimer: I'm talking small changes, not huge ones. Don't lean the jets both out 10 sizes in one change and then wonder why it hurt something. I know you wouldn't do that Dave but some people probably would.
I'd do a compression and leakdown before I would tear it down. If the compression and leakdown are fine, then don't worry about it. If the scratches are deep enough to matter they should show up on the leakdown test. Just make sure to do the leakdown at TDC with the valves closed of course.
As for the plugs, they look pretty good, but on an N/A motor with your compression and pump gas, I again would go on testing. Does it want more fuel? Did you try more fuel? I'd increase the jet size and see if it likes it down the strip. Based on your statement that it bogged down when the temp was lower I would guess it might want more fuel. If the oil temp is warm and the coolant is at least 140 it shouldn't bog down, it should run better with a cooler engine temp.
When you get to boosted engines and nitrous the window is smaller. On an NA motor you have a larger window to hit without damage. And If it goes faster with more fuel and the plugs don't foul I'd run more fuel even if the plugs look a little rich. The only way to know that is try it. Jet up 2 - 4 jet sizes on both ends and see if it likes it. If you are running a power valve in the primary only keep the split at least 10 I would say, maybe even more if it doesn't like the large primary jets around idle and cruising.
Its all a compromise, if it goes faster with larger jets but fouls plugs on the street than increase the split or start playing with larger PVCR and high flow power valves, tuning the bleeds etc.
Or get EFI, ha ha
I guess what I am saying on a low compression NA motor, just test and see what it likes. The plugs are secondary in my opinion, if it wants it let it have it, the car will tell you it doesn't like it before it should hurt anything, if its stops picking up then back off to where you were. If it goes slower to the opposite. Of course if you ever get detonation then back it off to the last known good tune (and fuel) before making another run.
Now if you were super high RPM, very high compression, or on nitrous or boost the window is smaller and stuff can go boom without much warning, then it's more important to look at the plugs before making changes, because if you make the wrong change, then you might have holes in your pistons.
Disclaimer: I'm talking small changes, not huge ones. Don't lean the jets both out 10 sizes in one change and then wonder why it hurt something. I know you wouldn't do that Dave but some people probably would.
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I was thinking of pulling the engine for a bearing check anyway, good time to pull the heads and get a real good look at it. This engine was first built in 94, at that time all the machining, balancing, mag, deburr etc was done. It was a regrind on the crank in 09, and some new rings. Probably has 4-5k miles on the original machine work, and at least 250-300 full throttle blasts on it.
I did a compression check last fall…
as far as the specs for those 5 last passes at the track….
110 fuel, 36* timing, it may like 38 better. Didnt try it this time out, but I did last fall and it was slightly better at half track and finish line, not sure if it was really timing related though, and ET and mph
this was under almost identical weather conditions in June… check the specs 38* against last weekend w 36*
same launch rpm, tire pressure etc. first slip is last weekend, screenshot is from June.
I did a compression check last fall…
as far as the specs for those 5 last passes at the track….
110 fuel, 36* timing, it may like 38 better. Didnt try it this time out, but I did last fall and it was slightly better at half track and finish line, not sure if it was really timing related though, and ET and mph
this was under almost identical weather conditions in June… check the specs 38* against last weekend w 36*
same launch rpm, tire pressure etc. first slip is last weekend, screenshot is from June.
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It dont bog once the engine is warmed up, but its definitely cold blooded until that first warmup cycle happens. I removed the choke plate, jets are 72/80 w 3.5 PV. lightest spring on the secondaries. Cant remember squirter size.
Valve lash is .015
Valve lash is .015
