12-28-2007, 12:38:20 AM
Now I know if it sounds to good to be true it probably is, but I was offered a 454 .060 over 9.5 comp. merlin II heads ported and polished never been ran for 1700. Heres the catch. The guy says you will have to fly cut the pistons.
The problem with that is the fact that the cam is only supposed to be .650 lift. The valve that is hitting is the intake. The guy is saying that he just never got around to it. I could be wrong but why would the intake valve hit. Doesnt that go aginst the suck squish bang blow. i would feel good about buying it if it was the exhaust, but the intake just doesnt make sense for a street engine.
I was thinking maybe this guy put the cam in wrong or used the wrong keyway on the crank. what do you guys think???
heres a list of the parts: assembled short block
solid roller cam
crane roller rockers gold
I figured even if the short block doesnt work out would the heads, cam and roller stuff be worth the $1700 even if I have to put it on my 427??
12-28-2007, 02:53:42 AM
WHy would the pistons be so tall if its only 9.5:1? Whats the deck height? Can you get away with installing a little thicker head gasket? Sounds like a good enough deal if you have the extra cash and can afford the "issue"
like you said, proally sell the pieces and make back most
12-28-2007, 06:23:47 AM
mike,, with a solid roller at that lift range,, if it's ground on a narrow lobe centerline angle and the cam is installed way advanced,, it will hit the intake valves first. although it sounds like it could be a missmatched combo like the other andy said. if it's only 9.5:1 compression with that much cam,, probably best to sell the parts.
not the best deal with a .060 over block as well. you can bore a 454 up to .100 over or a bit more,, but why weaken the cylinder walls any more than that. so,, you'd get one effective run/lifespan on the block before searching for another one on the next rebuild.
i have the L2307AF.060 pistons in my 467. has a .731.731 solid roller ground on 108 lsa installed straight up at 108 intake centerline with .580 dome pistons. i had to cut about I-.060/E-.080 on the valve reliefs from my pistons. on the basic trw generic forged pistons,, .650 is about the limit depending on the deck height/gasket thickness, valve diameters, and cam profile.
sounds like a missmatch of cam/piston like said though.... definately could use more compression with that much lift. guessing arround a 255-265@.050 cam. mine is 276/284@.050 with 13.0:1 compression. hope it helps.
12-28-2007, 09:56:02 AM
Buy it, swap the cam to something smaller and better matched to the compression ratio and have fun??? That's probably the route I would take. 'Fer instance..... in my 454 with AFR heads (2.25" intake, 2* rolled valve angle) and off the shelf domed TRW "LS6 replacement pistons" checks in at just shy of 10:1 compression and MILES of valve clearance with a modest Comp 282S solid flat tappet cam installed exactly to cam card specs (106* ICL against a 110* LSA).
Intake valve looks like it would almost always be the first thing to contact in a big block. Edge of the intake valve is very close to the bottom edge of the chamber, similar to a small block. But the exhaust valve sits an easy 1/4" up in the chamber. That's why you'll see many big block pistons that have only an intake valve relief (my LS6 pistons have no exhaust valve relief).
The heads and rockers alone would run you a lot more than that if you bought them new.
FYI- the reason for the relatively low compression is that those are open-chamber style heads, as most aftermarket BBC heads are these days. Tough to build compression without some farily sizable domes if you're under 500 ci. Obviously, with big domes and big cams you are always in danger of having a clearance issue with off-the-shelf pistons.
12-28-2007, 10:53:12 AM
Yeah, like Damon said - swap cams....or just sell off the solid roller stuff and go hyd roller with a smaller lift.
Or just go straight to a solid flat cam as mentioned and be done with it.
I wouldn't sweat it, but if you can get it for less for the CA$H price, then DUIT....
12-28-2007, 03:34:33 PM
I saw A 454 core for sail in the Atlanta adv. what do you wount for 1700 the parts arre worth that you would think .. I gave 500 for a 454 10 years ogo .
12-30-2007, 01:18:18 AM
THanks for the info guys. I dont know maybe I should play the lotto. I just got another offer for a 461 with gmpp rectangles on it from a guy I do know. in his 3200 split bumper ran10.80s for 1500 with about 20-30 passes on it intake to pan witha a new msd dist. just bought a 496. and now needs to pay the taxes on his house. This engine just got valvesprings and needs sparkplug wires and a carb to run. it aint solid roller but if I can get a 11.50 out of my 3800lb 81 z28 I could die happy (for now)
12-30-2007, 10:00:24 AM
Buy them both, I'm moving down by you so I can hang with you and score endless deals. Play the numbers someone's looking over you sholder and smiling down on you. Take advantage of it.