Hello, new on board here. Got the advice to join from a great local resource, Buffalo when i picked up one of his last remaining Nicson Exhaust Manifolds.
Been working and building cars and bikes pretty much all my life with my old man. Even already did a 235 Full Pressure in a 51 Chevy Coupe we built. I got the itch to finally get my own build in and the old man has a soft spot for 5 window Pickups. A good friend had a great start on a 54 GMC 100 5 Window. Tons of parrs, pretty much everything we needed to get most of it built.
Upon getting it home things started going no so good. He opted to drop the torque tube, who can blame him, and put in a 55T rear end with a Muncie 318. Well neither one was in really good condition so out with that and now has a bullet proof 9� and found and fixed up a low mile T5 to run behind the 248. During winterizing the motor being in a unheated barn, motor ran but had some rod knock, and upon examining the inside found lots of carbon, and some serious wear on the cylinder walls.
So I knew of a 270 locally, and knew it was a low mile rebuild, and i helped personally pull it out of the 2 ton wrecker the shop i help at do a V8 swap. So i made an offer and brought home the 270.
All it really needed was a few gaskets as they probably used 3-4 tubes of RTV squeezed out between layers. So i ordered a Best Gasket Kit off the interwebz and started tearing into it. Pull the valve cover off and the oil pan, and it looked super clean. A bit of oil sludge at the bottom of the pan but i half expected that. Pulled the timing gear cover off and the fiber gear looks brand new, again super happy.
But sadly thats where the good ended. I figured since i had the kit, id pull the cam out and sure enough no gasket or shim under the retainer. Pull the cam out and it looks brand new except for some scratches on the last bearing surface on the cam, then look at the bearing itself and appears ot was beat in with a screwdriver. And i am not talking about to stake it. Deep scratches and divots on the bearing.
So i started pulling rods and main caps. And one after another im finding trash and fod in under the bearings and scratches on the journals. My heart is sinking at this point.
Pull all the pistons out and not a joke pretty much all the ring gaps are dead in line, and the piston skirts are all knurled. And i have a tiny bit of rod slop but not terrible.
All the bores have a pretty good ridge at the top and some fresh honing marks telling me they probably just dingle balled the cylinders tossed some rings (3 out of six had rings out of order to the manual)
Crank has been turned for 10 unders and all bearings are 10 unders
Block is a D Block so it left the factory as a standard rods and mains with a .005 overbore.
The head is a different story. I have some sunk and some protruding valves. And i think it was not touched during rebuild. When i checked vakve lash i found they had set the lash with the motor 180 out. With it 180 out the #1 valves were in rocking position and #6 was tight. With it at TDC Compression #1 was tight. I am surprised how well this motor ran before we pulled it.
So hopefully I can drop the short block off with my local old school machinist. And he gives me good news.
I have a complete 248 for parts as well as another cam, crank and head. All 3 heads are small port. And to my understanding the 248 crank and 270 are the same?
Second part is finding 20 under rods and mains and prob 20 over piston and rings. All mine are flat top and not domed like Egge sells but even then it looked like all they had were standards.
So im stumped and a bit disheartened tonight. And apologies for no pics. Not letting me upload jpeg photos but can supply my Drive album privately if someone wants to see the pics.
Do not want to V8 swap this thing. I know personally what a nightmare it is. Lol. But i look to be heading down a deep rabbit hole getting this thing proper and running strong.
-Dan
Thanks in Advance
