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Post Info TOPIC: Budget SBC and Questions


- Ben #2 -

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Budget SBC and Questions
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I've got a small block I'm thinking of doing a budget rebuild on and looking for some insight. Got this from a friend who said it ran fine 10 years ago but he pulled it to put in an efi crate motor. Was developing a tick when he pulled it. He said it was a hi-po vette motor with low miles (aren't they all?). Ran the stamp numbers and it's a late 70's 2 bolt 350. 

Pulled it all apart yesterday and it is .030" over with trw L2256 flat top pistons, Comp 252H cam, 487 heads with 1.94"/1.5" valves. Timing chain was really sloppy.

My biggest questions are:

1. The cam looks and feels smooth, but there's jagged edges around the lobes. Would this just be casting flash from a cheaper cam or maybe the metal wearing down? (Pics) I'll get a new cam/lifters, mostly just curious if this was normal.

2. The rods on cylinder 1 and 2 wiggled just a tiny bit. Not side play but axial/radial play. Meant to get bearing pics but most of them look really copper or worn. I mic'd the crank journals and they all measure the same across the journals (at a few spots the width of the journal). 

I think I'll get the crank checked out, anyone have any suggestions where? I'll basically be building this for interim fun until I can put together the stuff to do a big block/manual swap, so I don't want to spend a lot on this motor. Cylinders look great. I figure I'll need gaskets, bearings, timing chain, new cam/lifters, rings (may reuse rings?), a little port work for the practice mostly and maybe shave heads a little to bump compression (after verifying what it is). Hoping for 300-325 hp, just a little more fun than the 307 really. 



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68 Malibu 307/PG. For now.....


- Beemer Brett - Redmond, WA

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I'm not expert but I'm sure others with more experience will chime in.
1. I think that's normal for the jagged edges. They are rough cast and the lobes and wear surface are ground into them. Lifter should ride more or less in the middle of the lobe. Looks like some of those lobes have a bit of irregular wear. May have quite a few miles or some metal started going through it. Obviously new cam and lifters!

2. Copper and worn bearings another indication of metal starting to go through system, dirty oil, or too tight. I would definitely measure the crank even if it looks good. No scoring or anything you can feel with a finger nail?

I would recommend doing a light hone on a drill and pop new cast rings on the pistons. Looks like it will be a fun build and should be able to get away pretty cheap.

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- Ben #2 -

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Nothing i could feel with fingernail. I did measure the crank quickly and everything was the same, but figure I should have someone more knowledgeable look at it. Haven't measured rod ends/bearings yet. 

But otherwise your suggestions sound like my initial plan: hone, cam/lifters, rings, burnouts. 



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68 Malibu 307/PG. For now.....



- Mike -
Puyallup, WA


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I would add I'd have the rods/pistons pin fit checked.

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'67 Chevelle -- 383ci, Jerico DR4, S60 3.54

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- Big George -

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avoid the Edelbrock "Performer" cam.
DO consider new valve springs and new cam, matched set ;)

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- Shane -
Graham, WA


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i ran this camshaft in a 350,with a performer intake and headers.194 heads.in a 72 gmc 3/4 ton with 3.55 gears. had a lovely choppy idle.made great power in the 2200-5500 area..

www.compcams.com/Company/CC/cam-specs/Details.aspx

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- Ben #2 -

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Thanks everyone for the input!

Hpaven't quite got to cam selection yet, but the one you posted Shane is one I wrote down. Also a few of the summit and lunati cam sets. Figure I want my usable power in 1500-5500 or so range. Anyone that went to Ben's bbq and drove to the cruise in knows I must have a stiff accelerator pedal I have to overcome right off idle. That thing just goes idle or floor....  

Biggest thing for me now is have my crank and rods checked out. I don't want to dump a bunch of money in this motor because it's robbing money from the ultimate goal of a big block and a manual. I talked to Terry that set up his machine shop in Bryant and I'm going to swing out there next week and he's going to measure stuff for me and go from there. I'll update as it goes.

And suggestions are more than welcome!



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68 Malibu 307/PG. For now.....


- Ben #2 -

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Here's some rod bearing pics if they mean anything. The main bearings don't look copperish like the rods do. 



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68 Malibu 307/PG. For now.....


- Durand -

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I have a pump gas friendly 454 for sale.
Fresh build comes carb to pan with ignition.
Runs 12.35-12.45 in the 1/4 in a 3700lbs car.

DSC_0007.JPGDSC_0009.JPG



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'65 Pontiac Lemans 468 t400 4.10 12 bolt

Best ET  11.43 @ 117.7



- Ben #2 -

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I've got a 454 already that I plan on building. The engine is just part of the equation though. I'd like to switch to a manual trans, better cooling system, better fueling system, upgrade brakes, exhaust, etc. I can't afford all that right now so as I gather parts and wait, I just figured building a budget sbc with more power than my current 307 would be an acceptable diversion of funds. If I find out crank, rods, etc. are not usable or will cost too much to be usable, then it all goes back under the bench and I just live with the 307 a little longer. 

 

But that fat block is sexy! Makes me want to paint mine and bolt it together as is just to look at it on an engine stand. 



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68 Malibu 307/PG. For now.....
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