I was concerned about the bubbling sound the coolant system was making when the engine was shut off. The cooling system seems to keep sucking air from somewhere. There's no external coolant leak and there's no coolant in the oil. Last time at the track, the engine was also running much hotter than normal.

Tonight I decided to try something. With the rad cap off and the water pump on, I cranked the engine over and coolant came bubbling out. That's not good. First thought is a head gasket so the first thing I wanted to try was to see if any head bolts were loose. Taking the driver's side rocker cover off, I found #7 intake valve outer spring broken. Must have been that 7000 rpm water box burnout I did before my best run. I guess I better hook up the burnout rev limiter to the line lock.

Checked all the head bolts on that side. All were tight. Pulled all the plugs and #7 was the only one that wasn't totally black. Did a compressed air test into all the cylinders to see which one produces bubbles in the coolant but couldn't pinpoint a cylinder.

Did a compression test. Passenger head was from 185-205 across all 4 cylinders. Driver head started good at 180 on #1 and #3 cylinder but #5 was 165 and #7 was 150 psi.

Looks like I'm pulling the driver side head to replace the head gasket and replace the broken valve spring. Hopefully I don't find anything else seriously wrong.

I was supposed to race tomorrow but I guess that isn't happening now. Too bad. It's a $100 to enter and $5000 to win if a minimum of 100 cars enter. Winner takes all. No runner up prizes. First round losers can buy back in for $20. I could empty out the company truck and go race but I need to work on the car now.

If I had a spare set of head gaskets, I do but not for this block, and a spare set of valve springs, I do but not for these heads, I could have it fixed in time for tomorrow.

What's interesting is that I had the car running last night and tonight and it still runs fine. I guess that means I ran my best time with 2 weak cylinders.

 

I need more valve spring pressure. The double springs w/damper don't have enough seat pressure. Time to upgrade to triple springs. Guess that means both heads are coming off now.

 

Sucks that the motor was hurt and you had to miss the big money race. However its nice to know your new best was down on power by not one, but TWO cyl. I'm interested to see what she'll do at 100%!! Think it'll go 9.0's?

 

how do you know that?

 

With an on head spring pressure tester.

 

ah, gotcha. So the spring pressure has declined since you installed them?
Can you put on the triples without machine work, or is that in your future as well?

 

Triples are the same diameter as my doubles. Installed height needs to be 2.050 while the doubles are only 1.950. Because I have longer than stock valves, there are shims under every double so I know the heads are capable of the triples. If I install them with less than 2.050 height, they'll just have more seat pressure. The doubles I was using had 214 pounds on the seat. The couple that I checked were down below 180. The triples have 304 pounds on the seat. The triples are actually what the camshaft is recommended to have.

Got the head off. Doesn't look like I need anything other than gaskets and springs. There's no indication that the valve ever made contact with the piston. From the look of where the head gasket let go, it may be time to invest in the extra head bolt stud kit that fills in that gap at the top of the cylinder with an extra head bolt. 2 cylinders per head need that extra bolt because of the head bolt layout on a BBC. The head needs to be modified for the extra studs putting the stud nut inside an intake runner.

The big question will be if the local speed shops have the springs I want in stock tomorrow. If not, they'll probably be able to get them the next day. I'd like to get it all back together before next Wednesday July 9. My car is needed at work for the company BBQ and that night is our next T&T.

 

Looking at that head gasket I can see why my crankcase pressure was high and pushing oil out the intake end rail gaskets. It was doing that on my first pass this year so I wonder how long the gasket has been bad? Maybe I should yank the other head off and replace that gasket also just to be on the safe side.

This is the stud kit I need. It doesn't have a nut inside the intake runner. The stud just needs a hole drilled and tapped into the face of the head using a head gasket as a template. You definitely want the hole square to the deck.

http://www.jegs.com/i/Dart/301/64210240/10002/-1

 

holy clean pistons, batman

 

That's because that cylinder wasn't working properly. Here's what one of the other pistons looks like and the combustion chamber/valves. So lets see what happens next time when I'm running on all 8 cylinders

The hole in the top of the piston is so that the spark plug doesn't touch the dome of the piston. These domes are huge to put the compression ratio around 13:1

 

PSI makes double springs that will work with your setup. I just put a set on my 406. 225 @ 1.950 and coil bind @ 1.160, I'm only going to be running a 650 lift cam though. What brand of springs did you have on there? Are they the ones recomended for the cam? Don't seem like you have had the engine together that long.

 

I'd love to get a set on Manley Nextek springs #221424. The heads were set up with Comp Cams 991 springs because that's similar to what they originally had. After checking the cam catalog, my cam actually requires 947 springs. Spring diameter for both are around 1.640". I doubt your SBC springs were that big. My lift is .748" These springs have been on the heads for 2 years and the cam was replaced shortly after the heads were done so the springs were actually for a different camshaft. Somehow I missed that.

I pulled off the broken spring tonight and checked the installed height. 1.950. Taking out the 2 large shims and leaving the small one, install height changes to 2.050. Perfect. I'll pick up a shim kit when I get the new springs just in case the rest of them are not as easy. I'm going to need a different valve spring compressor. The one I have won't handle the pressures of triple springs. It has trouble with these doubles. Not sure if I can rent the heavy duty model. I want one that can compress the springs while the head is still on the engine.

I've got a shopping list of things I need to pick up tomorrow. I want a set of Cometic head gaskets. If they have a set, I'll change both. If not then I'll replace the one head gasket with what I took out and put in a set of Cometics later on. Unless you damage them, Cometic head gaskets will be the last set you buy.

 

I wasn't saying you could use sbc springs, just saying that psi makes springs in the range you're looking for. They are smaller in diameter than what you're running. If you had a installed height 1.950 -.748= 1.202. Where do your springs coil bind? I have an installed height of 1.950 and my springs coil bind at 1.160. I have 225 seat pressure and open pressure at 550 @ 1.250. Sure wish I had an power spring compressor. Heck it took my son and I to put my heads together. I couldn't hold the head and compress the springs with my hand compressor. I should have bought +.200 long valves for my heads, and set them up at 2.030, so I could have ran a cam with more lift, but I didn't. The guy that balanced my engine likes a little less intake duration and about .100 more lift than I bought. Can't do it now, all new hardware.

 

The 991 springs have coil bind at 1.125. Adding a .060" safety margin, I was still ok.

The 947 triples have 304 pounds at 2.050. At .748 lift, open pressure will be 815 pounds

 

Engine is all back together and I fired it up tonight.

 

Glad to see it's all back together. I follow your racing pretty well on here.

 

You'd be surprised to know how many internet fans my car has. Lots of locals know it also from the local car forums.