Hello Everyone I am looking for advice for head gasket material for my 1968 430 Wildcat. Most suppliers only offer composite material head gaskets. The steel head gaskets don't seem to be around. What would you consider to be the best material to buy for head gaskets, composite or steel and if its steel where can I go to buy this type? Thank you John
If you have not had heads and deck resurfaced, you may do better with composites. The steels like a good surface. TA Performance has various composite and steel. https://www.taperformance.com/products.asp?cat=285
Hello Michael Thank you for your comments. I fitted new cylinder heads about 5000 miles ago, (and many years) and the block was reconditioned. It has been using coolant over the last year. Today I started looking for the issue and pressure tested the cooling system and found no leaks. I then compression tested the engine and right bank has compressions around 115 to 125. The left bank are around 150 to 115. The engine runs well and the spark plugs looked clean, so I will remove the heads and take a deeper look and most probably if nothing is obvious, I will have the heads magnafluxed. and hope like hell that they are not cracked. The engine has never run hot and the oil is not emulsified. Thank you once again. Regards John
You would want to follow up on that compression test, with a cylinder leakage test. Invest in that tester, it's not super expensive and it's going to be cheaper than R&R on the cylinder heads, looking for a ghost. I also recommend doing your cooling system pressure check, with the engine cool, and then again with the engine at or near operating temp.. if it's losing coolant, it HAS TO show up with a pressure test. Maybe 2% of these types of leaks are flukes that won't show up with that test. Dye the coolant with UV dye so the leak will show up with a UV light.. and you may have to leave the pressure tester on there for hours.. Look for coolant trails on the block, or around the radiator and hoses. Could be simply a hose leaking slightly at a particular temp. Tearing the heads off is way down the line in the diagnosis chain.. Re-torque them and see if your mysterious coolant loss goes away would be the first order of business with the heads. And yes, some casting number 400/430 heads are prone to cracking around the valve spring pads, although this usually does not produce a coolant leak, although it is possible, if the crack extends away from the spring pads far enough. Good luck JW
IF you're going to buy a cylinder leakdown tester, get one intended for aircraft use (cylinder bores less than 5") that has a "Master Orifice". The "Master Orifice" allows you to calibrate your expectations for the leakdown test results. This one is more expensive now than when I got mine a decade ago, but still not horrible. Be sure to ask for the 14mm cylinder adapter instead of the 18mm it normally ships with. https://www.aircraft-tool.com/Detail?id=2EM
If you want original Head Gaskets. They are still out there. https://www.ebay.com/itm/2545241059...409hShOLqLzsic5E32sHMS3g==|tkp:Bk9SR6yZ36LLYw
Hello Everyone Thank you for the replies and for your expert collective advice. I have taken Schurkey's advice and placed an order for a new Cylinder leak down tester. In the mean time I borrowed a Harbor Freight tester from a friend so that I can get on with this job. I have not started up the engine in recent months as it has a "large" transmission fluid leak from the front bell housing area. My plan was to get the car running and then put it up on a hoist to remove the transmission. Hopefully it is the front seal on the transmission. The leakdon test results showed; Cylinder 1 3% Compression 150 Cylinder 2 7% Compression 115 Cylinder 3 3% Compression 155 Cylinder 4 6% Compression 125 Cylinder 5 5% Compression 125 Cylinder 6 16% Compression 115 Cylinder 7 18% Compression 120 Cylinder 8 14% Compression 120 I had topped the radiator coolant up before starting the leakdown test and I soon noticed that the fluid was leaking out of the over flow hose, (cap had been removed prior to testing). I presume that this happened when I pressurised each cylinder. If I stopped the testing the fluid level settled down and stopped leaking. The leakage air noise seemed to come from the centre of the intake manifold. I would presume that from this situation I have a leaking intake manifold. I checked the torque settings for the Cylinder Head bolts and the Intake Manifold bolts and they all chcked out to their correct settings. As I said before the engine always ran well, it just used coolant. As Jim said it was like tracking down a "ghost". Your comments and advice will be appreciated. Regards John
If your doing a leak down test, both intake and exhaust valves are closed, therefore the ONLY way to pressurize the cooling system along with the cylinder being tested is either a bad head (crack), head gasket ( blown), or a cracked cylinder.
I don't know what "noise from the center of the intake manifold" means. Is the noise coming from the throttle body? From the intake gasket? From a crack in the intake manifold? It "sounds" like "the middle of the intake manifold" but actually escaping from an oil fill cap or PCV hose or somesuch? If the noise is coming from the throttle body, the intake valve isn't sealing. If it's coming out the oil fill cap, a crack in the manifold, or the PCV system, it's blowing past the rings. If it's coming out the intake manifold gasket, it's probably the rings but could be a failed seal on the intake port, which leads back to the intake valve. As said...if it's causing the radiator to overflow, it's a cracked casting or failed head gasket.
Hello Everyone Thank you Schurkey and Mark for your prompt reply, which is appreciated. I will perform "surgery" on the engine in the coming days and I am keeping my fingers crossed that at the worst case its a head gasket, as I had fitted new cylinder heads less than 5000 miles ago and they are hard to find. I had removed the dip stick prior to the testing and nothing came out of that hole. Looking at the results from the compression testing and leakdown testing, the problem seems to be coming from the rear of the engine, cylinders 6, 7 and 8. Thank you once again and I will let you know what I find. Have a great Easter weekend. Regards John
