[slowbird]

Haven't read all the post so not sure if it's been said, Ford runs 4 head bolts and they hold up good. 5 is better but 4 will do fine.
The number of head bolts isn't what causes Langer to replace head gaskets every 25-35 passes it's heat from the paired exhaust ports. The end cylinders are happy and could go a A LOT longer but the center cylinders just can't deal with that heat in that area

[PunchT37]

Originally Posted by shoebox1.1

Bulletproof engine.. only ruined by drunken idiots hitting roots bending cranks! HA!

Honda GC/GCV engines have NO head bolts.

[SRR]

Originally Posted by Sirrotica

That statement makes me laugh, I've been turning wrenches most of my adult life for a profession. I've changed a lot more SBC headgaskets that were blown than Pontiac. Only one Pontiac gasket in all that time and dozens of SBC gaskets that were blown.

As I said the engineering has to be correct for the 4 bolt per cylinder to work efficiently, Pontiac engineers got it right from the first design and even though bean counters and fuel mileage requirements lead to cheapening of the castings, the engineers seemed to have left enough heft to keep the head gaskets intact.

The worst GM division for blown headgaskets by far is Buick, in everything they made and designed, V8s and V6s had headgasket problems for many years. Working in a buick dealership it wasn't unheard of to have both of my bays with headgasket jobs...……………….....

Buick also used 4 bolts per cylinder, and they didn't get it right, not even close.

Olds used 4 bolts per cylinder and as far as gasoline engines they got it right, when the designed their diesel based on the same architecture it was flawed, however doubling the compression ration from 10.5 to 22 to one probably had something to do with that. Even though the increased the bolt size they still wanted to leak. I changed a few 5.7 diesel gaskets back in the day.

From your screen name I'd hazard a guess you're a chevy guy, lots of misinformation that circulates about why some feel chevy has a superior engine over other brands. Most of this circulates around the fact that GM made millions of them and they are dirt cheap to buy new and used parts for them. Superior engineering or manufacturing isn't the main reason for their popularity. Without the aftermarket the chevy would be severely handicapped if owners relied strictly on GM factory parts, as Pontiac enthusiasts did for so many years.

If chevy quit producing their own division engines in 1978, or 1981, (depending who you ask) as Pontiac did, I doubt there would be the following that Pontiac has sustained over roughly 40 years.

Which Buick engines? I've had numerous GM engines and never lost a head gasket. I think a factor not mentioned here is neglect and the engine being over heated to the point that the head gasket gives up the ghost. Most of the knuckle dragging public will just keep adding water or pouring in stop leak plugging up the coolant passages. Most of the problems with the later SBC engines were thin castings that would crack between the valve seat before the head gasket would give out. I remember a few years ago going into a machine shop and seeing 6 sets of SBC heads on the counter...all cracked between the valve seats. Yikes.

The prior owner of my Buick 455 used studded head bolts...maybe your right.

[Sirrotica]

Originally Posted by SRR

Which Buick engines? I've had numerous GM engines and never lost a head gasket. I think a factor not mentioned here is neglect and the engine being over heated to the point that the head gasket gives up the ghost. Most of the knuckle dragging public will just keep adding water or pouring in stop leak plugging up the coolant passages. Most of the problems with the later SBC engines were thin castings that would crack between the valve seat before the head gasket would give out. I remember a few years ago going into a machine shop and seeing 6 sets of SBC heads on the counter...all cracked between the valve seats. Yikes.

350 V8
455 V8
3.8 V6
4.1 V6

I worked in a buick dealership from 1982-1985. We were constantly doing head gaskets for customer pay work, as well as warranty work.

Coolant leaking into the cylinders and burning out the exhaust. Coolant leaking externally from head gaskets running down the block. Oil seepage between the head and block. Bowed deck surfaces on the blocks between cylinders leaking compression between cylinders.

The 4.1 V6 had 6 head gasket revisions while I was working there, many times we replaced head gaskets 3-4 times on the same car before the customer either got rid of it, or the warranty expired.

Buick had a real problem from 1970-76 on their V8s, and later on the same problems existed on the V6s until at least the mid 80s. If you overheated a V8 Buick you probably doubled the possibility of a blown head gasket, running one hot (stuck thermostat) was almost a guarantee of a failed head gasket.

Unrelated to the head gasket problem we had a few V6s that had porous castings that leaked coolant, and oil behind the flywheel too. That was GMs worst time that I know of for crappy castings and soft iron from trying to save a couple dollars cutting alloys out of the base cast iron to save money and causing premature wear problems of the cylinder walls.

I had a friend that used to do valve jobs in the evenings for extra money at his house, He bought a pickup truck load of late 70s SBC cylinder heads from a wrecking yard thinking he would get some un-cracked heads to replace the cracked ones he was running into. Out of the whole load of heads, he only got 3 heads out of the whole pile. I would guess 50-60 heads with 3 un-cracked in the valve seat area. 6% good 94% cracked...….LOL.

[Tom Vaught]

Originally Posted by slowbird

Haven't read all the post so not sure if it's been said, Ford runs 4 head bolts and they hold up good. 5 is better but 4 will do fine.
The number of head bolts isn't what causes Langer to replace head gaskets every 25-35 passes it's heat from the paired exhaust ports. The end cylinders are happy and could go a A LOT longer but the center cylinders just can't deal with that heat in that area

Have to agree, Brian, totally with that observation.
The center cylinders head material sees twice the heat cycles of combustion from the paired exhaust runners.
With most engines, ideally, you would have have each runner see one heat cycle in 8 firings. In the case of the Pontiac,
4 cylinders are seeing that double heat cycle. 3 and 5 on the drivers side and 4 and 6 on the passenger side.

50% more heat per engine combustion engine cycle than necessary vs using the Ford or RA-V exhaust design.
AND the Pontiac Engineers knew of the issue in 1967 and earlier, when they were doing the initial engine work on the RA-V engine.

Tom V.

[pastry_chef]

Originally Posted by John Langer

The head bolts are in the wrong place. There isnt enough material between the center combustion chambers, There isnt enough head bolts for the bore spacing.

Bore spacing vs head bolts, interesting.

[Schurkey]

Originally Posted by Sirrotica

I had a friend that used to do valve jobs in the evenings for extra money at his house, He bought a pickup truck load of late 70s SBC cylinder heads from a wrecking yard thinking he would get some un-cracked heads to replace the cracked ones he was running into. Out of the whole load of heads, he only got 3 heads out of the whole pile. I would guess 50-60 heads with 3 un-cracked in the valve seat area. 6% good 94% cracked...….LOL.

Sounds to me like the salvage yard cleared-out their scrap pile. I'm having trouble accepting that that high of a percentage of heads that were "supposed" to be good--or even a random sample of good/bad--would be defective.

I think they knew the heads were bad, and they dumped them on him.

[pastry_chef]

Originally Posted by Schurkey

I think they knew the heads were bad, and they dumped them on him.

Bingo! LOL but people can believe what they want.
Harvesting heads from the yards.. takes me back 25 years

Mark Jones frequently refurbishes and ports castings from the 70s, he builds hundreds of engines. https://www.youtube.com/user/VORTECPRO/videos

[Sirrotica]

Originally Posted by Schurkey

Sounds to me like the salvage yard cleared-out their scrap pile. I'm having trouble accepting that that high of a percentage of heads that were "supposed" to be good--or even a random sample of good/bad--would be defective.

I think they knew the heads were bad, and they dumped them on him.

The deal was, he kept what was good, and returned the rest, no one thought that there would only be only 3 good heads in that batch. I'm friends with both the owner of the yard, and the guy looking for cores. Just a lot of wasted effort for only 3 good core heads. GM put out a lot of crap during that time and lost their market share because of their greed.

Neither party knew what was good, or bad, until it was all over with, and neither party was trying to misrepresent the goods. I know the guy that was looking for good cores wouldn't have even started the project if he had any idea there would only be 3 usable heads out of the bunch, he was pissed he only got 3 cores for all that work.

Of course not every batch of 100 heads were defective to that ratio, or else no one would have bought their cars. (I never implied that in the post either..) There were 2 bad casting numbers that people steered clear of that were later identified, at that time no one yet knew what the ones to be avoided were.

This was right at the beginning of the bad heads, bad cams, SBC debacle. In 1978 I had a 305 1977 chevy Caprice with 17,000 miles with bad guides come in my garage for a ticking noise. At that time if you got 65,000 miles from the late chevy 305, you were blessed. The money making 305 tune-up was common in the late 70s early 80s. It consisted of new cam, lifters, timing chain and gears, pull the heads, and repair the guides and valves that were bad, and a valve job. If the heads were cracked, then new, or good used, needed to be procured. I did dozens of them myself. GM pushed a bunch of loyal customers to other brands during those years, that never returned.

[slowbird]

Originally Posted by pastry_chef

Bore spacing vs head bolts, interesting.

Hate to argue with Langer but Warp6 heads and RA5 heads don't burn the centers out of head gaskets, kind of points back to the paired exhaust ports and heat.

[Sirrotica]

GM later had a bulletin that even though there was a surface crack in the heads in that area didn't mean the head leaked water. It stated that the head needed to be pressure tested to be deemed junk. It went on to say lots of the castings were junked that were still serviceable. Just because of a visual inspection showed a crack, didn't mean they leaked water.

I know if it looked cracked we replaced it, so they could have been correct that the casting didn't leak water, but who wanted to chance putting it back together and warrantying it to be leak free when you could see the crack? That bulletin came out much later in the scheme of things, many had already been scrapped at that point by visual inspection only. The rush was over when that bulletin showed up.

[pastry_chef]

Originally Posted by slowbird

Warp6 heads and RA5 heads don't burn the centers

The split exhaust ports help for sure, but how many 1250 HP plus Warp6 or RA5 heads lay down regular passes at the track? None.

[slowbird]

Originally Posted by pastry_chef

The split exhaust ports help for sure, but how many 1250 HP plus Warp6 or RA5 heads lay down regular passes at the track? None.

I think bossbird would expose head gasket issues on ra5 heads by now. Nitro seems to find the weak link. And again if it was head bolt related why doesn't anyone ever blow out the end cylinders? Why is it that the gasket fails between the center cylinders right where the exhaust valves are everytime and no place else? Why when adding better cooling to that area do the head gaskets last twice as long? To me that all points to heat not a head bolt issue.

[pastry_chef]

Bossbird, the billet head is a different animal it seems.

Originally Posted by mgarblik

Believe it or not, we are still on our first set of head gaskets from 2011!. 10 head studs, 9/16". The secret is the solid, billet head. Thick and uniform around the studs, Eric did a wonderful design job leaving lots of clamp column around each stud. It's clamped down tight and doesn't move.

[slowbird]

Originally Posted by pastry_chef

Bossbird, the billet head is a different animal it seems.

No extra head bolts, they are located in stock location. I agree they're a different animal

[tom s]

Picketts layed down a bunch of quick laps with Warps when they were racing.They did not have 1250 HP,just 2.46 HP per CI with their 428.Ran high 7s in match race trim.Tom

[242177P]

Originally Posted by slowbird

Hate to argue with Langer but Warp6 heads and RA5 heads don't burn the centers out of head gaskets, kind of points back to the paired exhaust ports and heat.

Pretty sure you're both on the same page. Here's the entire post, because context. Note CENTER combustion chambers.

Originally Posted by John Langer

Pontiacs are junk, I dont know why anyone would ever want to try to build a serious race engine out of them. The bore is too small, the strokes are too long. The deck heights are too tall, the valve train geometry is whacked. The push rods are too long. The head bolts are in the wrong place. There isnt enough material between the center combustion chambers, There isnt enough head bolts for the bore spacing. The cranks are too heavy, the main and rod journals are too big. The cooling system is junk. the oil system is junk. The only good thing about them is that you dont have to pull the distributor to change the head gaskets every 7 passes. When I was making under 1000 hp head gaskets would last around 35-40 runs, under 1070 runs 20-25 runs, under 1090hp 10-15 runs, 1117hp, they leak after warming the motor up. A maximum effort Pontiac will never be able to compete with a maximum effort bbc. If I destroked my motor to 500" and put a dry sump on it and 2 dominators I think I could make close to 1100hp. NHRA pro stock BBC's make over 1430hp at the same displacement. That gap will never be closed!

[64speed]

I have been very fortunate. Blessed by the automotive gods you may say and my biggest fear is that my luck will run out with this mega dollar build I just finished. I have only ever had two terminal failures in my 25 years of driving. A 85 K5 Blazer and a 67 Buick Lesabre. The Blazer ran hot and I wasn’t paying attention cause as you know in those trucks the factory gauges suck. Water fills the oil pan, water begins to circulate and next thing you know a rod is making its appearance out the side of the block. The Buick was the one year only 340 and it was MINT beautiful car! Every option and truly owned by a little old lady. It had been sitting in her garage for years and I got it out and tuned it up and had the AC fixed and proceeded to cruise. I was doing about 85 down the interstate in the car about a year after I bought it and it suddenly acted like it had skipped a tooth on the distributor. Before I could get safely off the interstate POW and a windshield full of some good old antifreeze. I was determined to save that car and I looked everywhere for a 340. Never found one so I sold the car to a guy who rigged a 455 in it and then constantly stopped by when he saw me outside because this or that wasn’t working right. I have abused every make model and design of GM motor and I mean ABUSED and I have had no other failures. Before I knew what spark knock was my Lemans with 66 GTO 389 did it like crazy under hard acceleration. Never blew up or gave me any trouble but I would love to know what the bearings looked like when that motor got torn down. I guess they all have their shortcomings but I haven’t found them in GM V8s. And as far as brand loyalty the only other marque that may have us beat is the mopar crowd.

[AIR RAM]

Originally Posted by Tom Vaught

Joy Fair and Al Gonsales told me that the Pontiac block needed "tie bars" between the two heads to keep the blocks from cracking in the crank main web to camshaft bore area. Some members will remember I posted about this many years ago.

Tom V.

This is a bit off topic however since it was mentioned... I have to ask... LOL

Tom, this sounds like a modification that could be useful for those building (or running) our engines over 750HP+ level. Do you have any idea if they where they having any success with using the "Tie bars"?

Is there any pictures of what these would look like and how they would be installed? Where they just from head to head or head/block/head? I'm wondering if incorporating the "tie bars" theory into the engine plate and mid plate design would add and significant stability? If one where to make the mid/engine plates the shape of the front and back of the engine from the top of the head to the bottom of the pan with ears that mount to the frame... Would they offer significant rigidity at those power levels?

The "Tie Bar" idea seams to be a low cost mod that certainly will not hurt but could potentially be beneficial.

Any additional input you may have on these would be interesting to hear.

SPEED SAFE, NICK