Technical Blowing water pump gaskets on a SBC

I’m rebuilding a Sbc in my buddies 1954 Ford F100 . It keeps blowing out water pump gaskets . It literally disintegrates the gasket after 10min of run time. First try was felpro blue gaskets with Rtv. Destroyed! Second round just the plain felpro blue gasket . Same result. Very frustrating. Anyone ever have this problem?

 

What are the spacers on the bolts for? I’ve never seen anything like this before, what are you using for coolant? Torquing the bolts or tighten until they “feel right’?

 

never.

Looks like there's something hanging off the front of the pump, and the bolts are really long. Perhaps you have something that's making the pump move around? Move the camera back further, so we can see the whole picture.

 

I had the blue RTV blow out once, maybe it was old, my best defense has been Blue Monster, never failed me yet.

 

Are the faces on the pump flat and no bumps or lumps on them?

 

I've had a lot of SBC's never had a waterpump gasket leaking issue..now chrome aftermarket water outlet's are another story.
I use Permatex #2 along with any brand of paper gasket.

 

Never seen this before. Bad batch of gaskets...? They look more like shop rag paper than gasket material.

 

Leave the RTV off the gasket, it's not needed
It appears to me also that the pump is moving on the block, if you have to mount something off the front use bolts with studs on the heads, threaded rod with nuts at the pump, or double check the length of the bolts to make sure you are not bottoming out the bolts.

 

Is this a new pump? Did the block have this problem before, I’m guessing this is a “seasoned” block? If this was a cork-rubber gasket(I realize it’s not), I would tell you that you over torqued the mounting bolts and pushed the gasket out.

 

The engine has a CVF serpentine pulley system. New water pump. The block and pump surfaces are flat. Initial 30 minute cam break in at 2800rpm ,no leaks. Nothing was changed . First gasket was felpro blue with permanent black rtv. Didn’t leak during break in . Leaked days later with a 10 min run. I changed out the gasket today and replaced it with a felpro blue only. No sealant.... it leaked within 5-8 minutes.
The gasket oozes out. Never seen this before.CVF is sending us a new water pump. Yes its a reverse flow and we do have a reverse fan and clutch in place. Maybe the pressure is blowing it out. May get a new radiator cap.

 

Torqued the bolts at 30 ft lbs

 

Make sure the mounting flanges are flat.
Clean up threads in the block.
Make sure the bolts are the correct length.
If too long, it won’t seal.
Toss the blue RTV in the nearest garbage can

 

Bolts are correct length . Did not use RTV second time. Awaiting manufacturer to send us another water pump. Really can’t explain why no leaks during the cam break in.

 

Have you checked the mounting surface with a straight edge?

 

Is all that " Stuff " on the front of the engine all hanging on just the 4 water pump bolts , or are there other attachment points on the front of the engine ?
If all that " stuff " is hanging on just the 4 bolts , I think it's trying to move around because of the belt pull from the crank pulley to all the accessories .
Factory mounts spread the load out to attachment points on the block as well as the pump for a reason .

 

Is the timing cover hitting the back of the pump causing it to seat improperly? The gasket’s sealant blown out like that suggests the two surfaces aren’t fully mating.

 

Thermostat stuck shut? I had one stuck on a 307 and it blew the water pump shaft and fan into the radiator.

 

Yea. Also had one hit a timing cover

 

Is there a spring loaded tensioner on the belt? If not, maybe a pulley is not concentric and the water pump is being pounded with loaded/unloaded cycles.

Gary

 

Do the reverse flow pumps/engines have any specific differences in plumbing the heater core? Just grabbing at straws here, but maybe try disconnecting the heater core and shunting the hoses together at the engine?

 

I installed one of those CVF serpentine kits on a customers car. It was a huge POS. It rattled and loosened bolts and ultimately broke bolts. It was on a Small block Ford but the engineering was poor to say the least.
My guess is all that load on the 4 water pump bolts, and an alignment/balance/load/torque/ design problem are the issue.
I too am in the I’ve never seen any water pump gaskets fail like that on any engine, in any timeframe.

 

You might have to build extra support for all that weight hangin out there,

 

When you rev it , You should see it .if thats the problem,

 

I've seen/installed similar kits but they used studs in the block and the spacers were threaded at either end. That way, you can get the water pump nice and snug using the spacers (like a tie rod adjuster) and then the brackets bolt to the other end of the spacer (IE, no long-***ed bolt trying to hole everything in place). I might try that if you find your water pump/timing cover clearance is good.

 

The block was cleaned

 

The gaskets look like they've been hammered....I also think you have too much **** out there, moving around, and the problem is that the drive system is a bad design.

Good luck....

 

Run temps sitting 180 -200. Thermo is working. I too was a bit cautious on the CVF system. I did do a little research prior to installing this. Bolts are high tensile strength so no worries about stretching. Having four bolts really balances the aluminum bracket which holds only the alternator, power steering pump , tension pulley and idler pulley. The aluminum spacers aids in equal load distribution . I did run a dial indicator on this set up in a crank no run and had zero movement. There is plenty of clearance from the water pump to timing chain cover.
Funny thing is how both gaskets are blown outward . If the 16 psi( 1.1 bar) radiator cap is not dumping at its pressure this just might be the culprit. Pressure goes out in all directions. This gasket seems to follow this. I’m calling felpro tech guy’s tomorrow and going to run my issue by them. This is definitely frustrating.

 

Hmmm short water pump.. do you have correct timing cover?

Proform Parts SBC SB Chevy Steel Chrome Timing Chain Cover 141-904
Timing Covers, 1-Piece, Steel, Chrome Plated, Chevrolet and Bowtie Emblems, 1955-1995, Chevy, Small Block, Gen I, Each

UPC: 037995869046
Cover Style: One-piece
Cover Logo: Chevrolet and Bowtie Emblem
Cover Material: Steel
Cover Color: Chrome
Timing Pointer Included: No
Bolts/Studs Included: No
Gaskets Included: No
Quan***y: Sold individually

Notes: Supplied with GM production oil seal

May require extra gasket thickness or shim under short pump to clear cover

 

Correct TC. stock Chevy

 

squirrel is right too much **** on 4 bolts a bad design