Tomorrow I'm picking up a complete running (though not well) 71 455 from an Estate wagon. I think this is a 10:1 compression motor but I'm not sure. Anyway, as long as I don't find any big issues I plan on slapping in new bearings, mild cam, rings, honing job and valve job... as well as new oil pump and such. If I find the cylinders are worn then I'll have to have new pistons fitted, which brings up my main question. Any piston manufacturers have 9:1 pistons on the shelf? Below is a video the PO made to show that the engine does run. The adapter and carb are there because the factory carb is shot... needles to say I'll be rebuilding that too. Any comments? http://www.youtube.com/watch?v=3HADiOAJ4mU
Does it smoke? It needs lifters or maybe the oil pressure is so low they won't pump up.. Look at the bearings and do a leak down test. You may just need a cam and lifters which isn't bad since you want to put a mild cam in anyway. The 71s were an 8.5:1 engine. Good Luck Bob H.
Thanks Bob. 8.5:1 compression for a 455 seems low... I thought all the 71 455 4 barrels were 10:1 and the Stage 1 was 10.5:1. Will need to do more research before I get started on this.
Up to '70 the compression was 10:1, stage or not. Bob's correct, in '71 it dropped to 8.5 This was achieved by increasing the cc volume of the dish in the piston from 25cc's to 42cc's. Lot's of good info on George's site. http://www.buickperformance.com/pistons.htm
I was going to look into this engine too, craigslist huh? I'm also located in San Jose, Nice car by the way, $350, is not too bad, you can build it
First off... Sorry for posting this in the wrong form, as this will not be a racing engine. My bad. Can anyone move this over to the correct form? 68Rivi... Have I met you at any of the meets? Yes, I did get it via Craigslist, but for $300. A friend has lent me Steve Dove's GS book and it says that it is a 71 TR (engine code) w/ 8.5:1 pistons and rated 315 HP. Will start cleaning it up next week during the holiday, hopefully I'll also have time to do a leak down test. I'm most worried about the cylinder ring wear, w/ 100,000+ miles there's about a 75% chance I'll need to bore and fit new pistons. Would love to find some 9:1s. The same friend is going to open up his parts cash and make me a deal on a Poston Stage1 cam and an aluminum intake, not sure which but he did say it was the best one for a mild build street engine. Regardless of the ring wear I'm sending the block out to be checked, drill out the oil galleys, hone the cylinders and install the grooved cam bearings. Took me 3 sets of cam bearing to get them in right on the 340 I did last year... and I'll not do that again. I'll also install a booster place in the oil pump along with new impellers and send the carb out to have it rebuilt and reworked. If I have time I'll do some mild porting to match the ports, not sure if it's really worth the time. I did the port match on the 340 and that took forever, most of that work was on the intake. Thanks,
