It's been one year since I last posted regarding this project. I found other projects including my Land Rover and my Audi A4 Avant taking up my attention and money over the past year. (The Land Rover was a money pit!--thankfully it is now gone!)
I have to admit that the setback really cooled my motivation for this project. I did very little with the Corrado since May of 2013. My brother is also rebuilding his G60 Corrado and he's actually made some progress rebuilding a spare PG block that I have given him earlier. We've worked together often and have exchanged parts frequently. This is the only thing that has made me continue forward.
His intention was to rebuild a PG block and put it into his corrado. He used a spare block that I had in my garage as a basis for his rebuild. The spare block was tanked and cleaned thoroughly. Then ARP main bolts were installed on the block as well as ARP studs on the crank arms. Crank arms were cleaned and balanced. Once the mains were installed, then an align bore was performed on the block. Each cylinder bores was honed and new pistons, rings and wrist pins were purchased in stock size. We were ready to reassemble the short block--or we thought we were ready.
Closer inspection of the crank revealed that the block I had purchased from a fellow corrado owner in San Diego had experienced a failure at the woodruff key near the main pulley. This is not uncommon for these PG blocks. The damage occurs at the end of the crank and the result is the main pulley will spin on the crank. Looking back in hindsight, I wish the seller would have revealed this to me this before I bought the short block. Lesson learned. Although it is repairable, its not one of those repairs that inspires confidence once one starts to rebuild a motor. My brother was about to install new bearings and reassemble the short block with standard sized pistons. It was when the crank was cleaned and polished that he noticed the damage. So the crank from the used PG block was not going to be used in this project. So my brother used the crank from his original PG block to continue the rebuild. It was cleaned and polished at the machine shop and proper main bearing were purchased. That problem has been solved.
To our disappointment, closer inspection of the finished block revealed that there was a noticeable "edge" in the cylinder walls where the previous rings would contact the cylinder walls. It is barely visible but one could feel the ridge left behind if one rubbed their finger inside the cylinder. This ridge would not be ideal for the new rings. If assembled, the ridge could possibly damage the new rings resulting in oil passage through the engine. Even worse, it could prematurely fail the piston rings and I'd have to rebuild the block once again. So that's where it stands at this point.
My brother has been preoccupied with two other motors for his MK1 Caddy and his MK1 Jetta Coupe. So he told me that if I bought the other necessary parts he would assemble the engine block and whomever could use it first would get the motor. We'd still have the two original engine blocks as platforms to rebuild which ever car remains to be rebuilt. So the next step is to bore out the cylinders to the next size and buy the appropriate pistons. I have a choice of boring up the next size overbore that would eliminate the ridge (Guesstimate is 82.5mm) , or step all the way up to a 1.9 liter motor. (83mm) Either way, piston set with rings and wrist pins is going to cost around $550 for the set of four.
Moving on to the cylinder head, I removed it to have it rebuilt in a shop. Once the head was out of the car, I discovered why it was so difficult to pass the smog certification previously. It took me three attempts before I finally overcame the high oxygen levels in the tailpipe. Upon closer inspection, I discovered that two exhaust manifold studs had broken off and air was entering the exhaust system ahead of the catalytic converter. I purchased two brand new catalytic converters before I finally passed the test. So whomever does the rebuild on my cylinder head will have to remove two exhaust studs too. I'll use the extra catalytic converter on my Golf MKII project car.
I'll decide which size pistons then purchase the set. I'm inclined to stay with the 82.5mm pistons which allows me the option to rebuild once more in the future. Cylinder head is now off and on its way to a machine shop for its rebuild.
This project is on life support but it isn't dead just yet.
I have to admit that the setback really cooled my motivation for this project. I did very little with the Corrado since May of 2013. My brother is also rebuilding his G60 Corrado and he's actually made some progress rebuilding a spare PG block that I have given him earlier. We've worked together often and have exchanged parts frequently. This is the only thing that has made me continue forward.
His intention was to rebuild a PG block and put it into his corrado. He used a spare block that I had in my garage as a basis for his rebuild. The spare block was tanked and cleaned thoroughly. Then ARP main bolts were installed on the block as well as ARP studs on the crank arms. Crank arms were cleaned and balanced. Once the mains were installed, then an align bore was performed on the block. Each cylinder bores was honed and new pistons, rings and wrist pins were purchased in stock size. We were ready to reassemble the short block--or we thought we were ready.
Closer inspection of the crank revealed that the block I had purchased from a fellow corrado owner in San Diego had experienced a failure at the woodruff key near the main pulley. This is not uncommon for these PG blocks. The damage occurs at the end of the crank and the result is the main pulley will spin on the crank. Looking back in hindsight, I wish the seller would have revealed this to me this before I bought the short block. Lesson learned. Although it is repairable, its not one of those repairs that inspires confidence once one starts to rebuild a motor. My brother was about to install new bearings and reassemble the short block with standard sized pistons. It was when the crank was cleaned and polished that he noticed the damage. So the crank from the used PG block was not going to be used in this project. So my brother used the crank from his original PG block to continue the rebuild. It was cleaned and polished at the machine shop and proper main bearing were purchased. That problem has been solved.
To our disappointment, closer inspection of the finished block revealed that there was a noticeable "edge" in the cylinder walls where the previous rings would contact the cylinder walls. It is barely visible but one could feel the ridge left behind if one rubbed their finger inside the cylinder. This ridge would not be ideal for the new rings. If assembled, the ridge could possibly damage the new rings resulting in oil passage through the engine. Even worse, it could prematurely fail the piston rings and I'd have to rebuild the block once again. So that's where it stands at this point.
My brother has been preoccupied with two other motors for his MK1 Caddy and his MK1 Jetta Coupe. So he told me that if I bought the other necessary parts he would assemble the engine block and whomever could use it first would get the motor. We'd still have the two original engine blocks as platforms to rebuild which ever car remains to be rebuilt. So the next step is to bore out the cylinders to the next size and buy the appropriate pistons. I have a choice of boring up the next size overbore that would eliminate the ridge (Guesstimate is 82.5mm) , or step all the way up to a 1.9 liter motor. (83mm) Either way, piston set with rings and wrist pins is going to cost around $550 for the set of four.
Moving on to the cylinder head, I removed it to have it rebuilt in a shop. Once the head was out of the car, I discovered why it was so difficult to pass the smog certification previously. It took me three attempts before I finally overcame the high oxygen levels in the tailpipe. Upon closer inspection, I discovered that two exhaust manifold studs had broken off and air was entering the exhaust system ahead of the catalytic converter. I purchased two brand new catalytic converters before I finally passed the test. So whomever does the rebuild on my cylinder head will have to remove two exhaust studs too. I'll use the extra catalytic converter on my Golf MKII project car.
I'll decide which size pistons then purchase the set. I'm inclined to stay with the 82.5mm pistons which allows me the option to rebuild once more in the future. Cylinder head is now off and on its way to a machine shop for its rebuild.
This project is on life support but it isn't dead just yet.
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