It sounds like quite a few heads ----- crack ------ Any ideas why? You mentioned that the two center pistons had gotten hot ----- maybe a cause ----- and why hot ---- maybe carburetion ------ any particular year more so than others? ------ A good tip ----- if putting on a Header and head is off ---- get Header down in first and the tip of leaving out the two studs on the end to get a Header in ------ Curios though about ---- what's making the Heads crack ----- I have a '69 MGB-GT --- Thank you for the video ---- Hope you have a Good week ---- Rodney
The two center pistons got hot because both exhaust valves had receded to the point that they were leaking pretty bad, and that is a result of running unleaded fuel for years without hardened seats. Almost all of these cylinder heads nowadays are more than 40 years old, while cracking has always been a bit of an issue as more time passes it just becomes more of an issue. The worst ones are the rubber bumper cars as they had an induction hardened valve seats instead of inserts, the difference in the expansion rate of the two hardness areas causes cracks over time.
Ask three mechanics, and you’ll get three different answers to that question. In this case, I had three lifters in stock, and I replaced all three that showed even the slightest bit of surface hardening coming off. I know many will say you should just replace them all though.
MGBs had a terrible reputation for failing without strict adherence to the service interval. It was if the damned thing knew when you got to 3001 miles. Coz that's when it failed. Anyone that owned the MGB or GT spent more time repairing it than driving.
In my experience they tend to be as reliable as the work that was done to them. The reliability is on par or better than just about anything else from the same time period. I have been driving my BGT for 25 years and so far it has never had to be towed even once. I have had customers drive for many years with little more than just regular maintenance, and even drive across the country with no issues. Anyone who has spent more time repairing one than driving it either had a terrible mechanic or is/was a terrible mechanic.
Excellent comments. Thank You
My 1964: found crack in head; repaired via thermite welding
It sounds like quite a few heads ----- crack ------ Any ideas why? You mentioned that the two center pistons had gotten hot ----- maybe a cause ----- and why hot ---- maybe carburetion ------ any particular year more so than others? ------ A good tip ----- if putting on a Header and head is off ---- get Header down in first and the tip of leaving out the two studs on the end to get a Header in ------ Curios though about ---- what's making the Heads crack ----- I have a '69 MGB-GT --- Thank you for the video ---- Hope you have a Good week ---- Rodney
What is with all of the hyphens? Ever heard of commas, full stops? Really weird.
The two center pistons got hot because both exhaust valves had receded to the point that they were leaking pretty bad, and that is a result of running unleaded fuel for years without hardened seats. Almost all of these cylinder heads nowadays are more than 40 years old, while cracking has always been a bit of an issue as more time passes it just becomes more of an issue. The worst ones are the rubber bumper cars as they had an induction hardened valve seats instead of inserts, the difference in the expansion rate of the two hardness areas causes cracks over time.
Thank You
5:45 If you find one lifter with an issue, do you only replace that one? Or do you replace all lifters?
Ask three mechanics, and you’ll get three different answers to that question. In this case, I had three lifters in stock, and I replaced all three that showed even the slightest bit of surface hardening coming off. I know many will say you should just replace them all though.
@@mgbgtguyThanks, clear reply.
MGBs had a terrible reputation for failing without strict adherence to the service interval. It was if the damned thing knew when you got to 3001 miles. Coz that's when it failed. Anyone that owned the MGB or GT spent more time repairing it than driving.
In my experience they tend to be as reliable as the work that was done to them. The reliability is on par or better than just about anything else from the same time period. I have been driving my BGT for 25 years and so far it has never had to be towed even once. I have had customers drive for many years with little more than just regular maintenance, and even drive across the country with no issues. Anyone who has spent more time repairing one than driving it either had a terrible mechanic or is/was a terrible mechanic.