Restarting My '70 Nova Project

BravoXray · Aug 28, 2024

UPS dropped the heads and gaskets off today, so I got started putting it back together. The AFR heads are really nice pieces of equipment, and although they are an as-cast head, the unmachined cast surfaces are pretty smooth. The water passage that was the problem on the Procomp heads is properly located, but I forgot to get a picture of them.
I applied sealant to the head studs and installed them in the block. This is messy, as some of the sealant always ends up on the block deck, and it's a pain to get it all wiped off. Sliding the head gasket down over the studs is a fiddly process, but you can't really put it on first because of the thread sealant mess. The heads slid part way down, as is usual when using studs, but some gentle work with a dead blow hammer got them seated all the way down.
The stud's threads and nuts have to have a coating of ARP lube, which is a bigger mess than the sealant, just as bad as never seize, but black.
After snugging them up, I torqued the nuts to 30 ft lbs, 50 ft lbs and final torque of 70 ft lbs.
I still have to align the pushrod guide plates and torque the rocker studs, but at least the heads are back on.
One other thing different on these heads that the plugs are set in the head at an angle, leaning them away from the header pipes, which will help keep from burning plug boots.

Alan46 · Aug 29, 2024

BravoXray said:
UPS dropped the heads and gaskets off today, so I got started putting it back together. The AFR heads are really nice pieces of equipment, and although they are an as-cast head, the unmachined cast surfaces are pretty smooth. The water passage that was the problem on the Procomp heads is properly located, but I forgot to get a picture of them.
I applied sealant to the head studs and installed them in the block. This is messy, as some of the sealant always ends up on the block deck, and it's a pain to get it all wiped off. Sliding the head gasket down over the studs is a fiddly process, but you can't really put it on first because of the thread sealant mess. The heads slid part way down, as is usual when using studs, but some gentle work with a dead blow hammer got them seated all the way down.
The stud's threads and nuts have to have a coating of ARP lube, which is a bigger mess than the sealant, just as bad as never seize, but black.
After snugging them up, I torqued the nuts to 30 ft lbs, 50 ft lbs and final torque of 70 ft lbs.
I still have to align the pushrod guide plates and torque the rocker studs, but at least the heads are back on.
One other thing different on these heads that the plugs are set in the head at an angle, leaning them away from the header pipes, which will help keep from burning plug boots.

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Thanks for the update!

Fuddyduddy1952 · Aug 29, 2024

Curious if you cc'd the piston dish(es) and combustion chamber(s)?
That w/ crushed head gasket what will the static compression be?
Have you checked cam degree?
(My gearhead wife wants to know

)
She went into this lengthy diatribe about SBC 400, heads, steam holes, etc.

BravoXray · Aug 29, 2024

Fuddyduddy1952 said:
Curious if you cc'd the piston dish(es) and combustion chamber(s)?
That w/ crushed head gasket what will the static compression be?
Have you checked cam degree?
(My gearhead wife wants to know )
She went into this lengthy diatribe about SBC 400, heads, steam holes, etc.

Yes, when I assembled the engine I calculated the static compression ration, taking all those things into account.
Attached is the spreadsheet I used to calculate it.
The static CR is 10.784:1, dynamic CR is 8.08:1.
I also degreed the cam when I installed it. I set it straight up, neither advanced or retarded.
The cam is a Comp Cams Nostalgia 30-30H, a hydraulic grind equivalent of the old 30-30 cams used in 327 350HP engines, and also maybe in the Z-28 302 engine. It's actually a pretty mild cam with only .483" intake and .477" exhaust lift, with 239° and 246° durations at .050" lift and 112° lobe separation.
It does sound pretty nasty though.
The 400 SBC was/is a controversial engine, with siamesed cylinders with 4.125" bores and 3.76" stroke, some saying it's junk, others love them. The important thing when building a 400 SBC based engine is having the bores sonic tested to verify cylinder wall thickness, which I did have done on my block. I also had to drill additional 3/8" holes in the deck that aid coolant flow.
I used an Eagle stroker kit with 6" rods and 4.155" pistons that is internally balanced, so I don't need the externally balanced flywheel or harmonic dampener. The rods are machined asymmetrically to clear the camshaft with the long stroke.

I got the pushrod guide plates aligned and torqued down this afternoon. Then I installed all the pushrods and tocker arms and set the lash/preload on the valves.
I installed the intake manifold and gaskets and for the first time, I used a bead of RTV on the China Walls or ends of block, instead of using the cork of rubber gaskets. A 1/4" tall bead laid out seems to have worked well, with some being squeezed out, so it should seal just fine.
I installed the 1/4" studs I use in the heads for the valve covers, as it makes installing the gaskets and covers a lot easier, and installed the valve coders.
The I rolled the engine over and wiped the pan rail down and put a dab of sealant in the corners where the rear main and timing cover seal, laid the pan gasket on it and set the pan in position. The Fel-Pro 1880 gasket is a blue silicone gasket with a steel core and inserts to prevent over torquing the gasket, and it works really well.
Lastly, I filled it with oil and used the oil pump priming shaft and drill to prime the oil system.
Tomorrow, I'll get the flywheel, clutch, bellhousing and transmission installed and it will ready to get back into the car. Again.

Alan46 · Aug 30, 2024

It seems to me that you sure have done your homework!

Sorry, couldn’t help myself!

BravoXray · Aug 30, 2024

Nor could I.

BravoXray · Aug 30, 2024

Well, it's back in the car, again.
Put the flywheel, clutch, bellhousing and transmission on this afternoon. Got it rigged up on the cherry picker with a ratchet strap to get the angle right when I lowered it back into the car. It went in without a hitch, and got the trans mount in and bolted up and the motor mount bolts in and tightened up.
I also put the distributor in and hooked up the coil and oil pressure wires, after spending a while searching for the nut for the oil pressure sender that I managed to drop into the black hole that resides somewhere at the back of the engine. I ended up getting a new one and using it. The old one will undoubtedly get regurgitated as soon as I start the engine, and will be staring up at me when I move the car.
That was it for today, it was really hot and humid and I don't function well when sweating profusely.
It's supposed to be a lot cooler and less humid tomorrow, so hopefully I can get it wrapped up and ready for the road.

dodge man · Aug 31, 2024

I hope once you get it fired up and running you get to enjoy it a while.

BravoXray · Sep 3, 2024

Well, I'm an idiot sometimes, but we'll get back to that in a few minutes.

So, Saturday I worked all afternoon getting everything reassembled and reconnected on the car. Filled the cooling system, everything looked good. When I started it, the loud scraping noise let me know I didn't get the flywheel cover positioned correctly and it was rubbing the crank flange.
Well, horse hockey! I was beat, so I decided to fix that on Sunday.
Of course, to get one of the four bolts that hold the cover in place, you have to remove the oil filter. Messy job, but got it done. Started it up, no more noise, so I let it run for 10 minutes or so and shut it down. That's when I noticed coolant still dripping from the starter area. I used some of my most vile language to describe my displeasure with the leak still being there. Went back up to the house and sulked for a while.
Went back down on Monday, started it back up and let it warm up to operating temp, and the leak nearly stopped.
Hmmmm.
I decided that since it had been heat cycled a couple of times, maybe the head bolts might need retorquing. It was worth a try. I had to take the plug wires off and the header loose from the head, and with a rigged up offset adapter for the bolts under the exhaust ports, the rest I could used a regular 12 point socket on. All the bolts (actually nuts, I have studs installed) were down 5 to 10 ft lbs, so I brought them all back to 70 ft lbs and put it all back together.
I started it up and after a few seconds, it started backfiring quite often, really loudly. Shut it off and checked everything over, but when I restarted it, more backfiring.
More foul language ensued.
But, the leak slowed to only a couple of drips over 10 minutes or so.
Time to mow the yard and sulk some more.
Today I went back down and tried to fathom what was causing the misfire. I pulled the valve covers and rechecked all the valve adjustments, they were good. Pulled the distributor cap and rotor and they looked good. I even hooked up the timing light and rechecked the timing. It was right on 14° BTDC, right where it should be. Finally I decided to pull the plugs, as I was about out of ideas. The left side plugs looked good. Then, when I went to pull the wires off the right side, I discovered I had somehow swapped the wires on #2 and #4 cylinders when I had reassembled it after taking the header loose. I have no idea how I managed that, but I spent a good four hours chasing down a stupid mistake.
Swapped to wires, started it up, sounded great, no backfiring. Diet Coke to celebrate!
The funny thing was, with the wires swapped, it really didn't have a noticeable miss, it sounded fine otherwise.
So, I buttoned everything up and took it for a 15 mile test drive and everything is fine. No oil leak and no apparent coolant leak.
I think I'm going to retorque the left head also, but it's going to be more difficult with the brake booster and header in the way. I ordered a Proto torque adapter from Amazon for the 1/2" 12 point nuts that will work better than my rigged up one.
Tomorrow I'll call the alignment shop and get a date setup to do that, and then I just have the problem remaining of the drip rail trim and how to get that installed.
So, it looks like Thursday I can finally take the Nova to the cruise-in at the Essen Haus.

Oh yeah, when I was pulling the plugs on the left side, I found the bolt for the steering shaft coupler I had lost. It was laying under the inner fender splash shield, Not sure how it got there.