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SBC build

4K views 48 replies 18 participants last post by  NewdRiver_ 
#1 ·
I know its just an engine build, but I figure that I should document this stuff somewhere, and you guys like looking at pictures.

The motor is a small block Chevy, your run of the mill 2 bolt 350 out of a '77 Camaro. Looks like it is all virgin. Came in the Jeep. Ran well enough to drive it home. Then it sat, for 3 years while I was away at college and had no money.



We moved a year ago and it ran fine going onto and coming off of the trailer. Then it sat, for 8 months, in the garage. I was going to paint the block proper orange and clean everything up. Took the plugs out and rusty water started shooting out. Uh oh.



I guess water or condensation got through open valves?

Cleaned the walls. #3 has some pitting.

I wanted to build a hotter motor and drop it in when I was ready, but I don't have that option anymore. I want to drive this damn Jeep already.

I talked with some of you guys, my machinist, and Comp Cams, and I have a plan of attack.

My budget is $1500, but I'll spend more if it means not cutting corners. Nothing crazy, just a slightly-over-stock rebuild. I'll keep a running total.

I scored a set of 062 Vortec heads off my friend's toasted Suburban engine. They might need a valve job. All of the seats and seals looked clean except for one exhaust valve that is a little rough. Machinist said he might be able to just lap that one. Hopefully all they will need is a hot tanking and the guides trimmed. If he recommends a valve job or replacement valves, then I'll do it. Reusing the stock self-aligning rockers.

Machine shop is going to hot tank, freeze plugs, bore 0.030" over, and install cam bearings. My crank is a bit groovy and might need polishing as well.

The pistons will be -12cc dished 1.561" CH. These.

Head gaskets are 0.026", bringing the static CR to 9.34:1.

The cam is a Comp 12-318-4. Comp thought this was the best fit for my application, and what I wanted to do. I'd hate to say it, but she's going to be cruising on Saturday nights more than on the trails, and I'd rather trade off a bit of low end torque for a rumpity idle and more mid range. It's extremely similar to the Isky 270 Mega that someone else on here recommended. I was shocked that Comp recommended their equivalent cam.

I'll be flushing and buying a friend's B&M 2500 stall. The electric fan should be able to handle the extra heat this will put out.

This cam brings the DCR to 7.65:1 and the cranking PSI to 150PSI. Well within pump gas territory.

I just finished rebuilding my Quadrajet. I'll also be needing an Edelbrock Vortec intake.

I'll update as things progress. Going in to the shop Monday.



-------------------------------------------------
Spent so far:
Cam, lifters, locks, retainers, seals, springs: $359.23
Head gaskets: $53.98
Oil pump: $22.95
Pistons: $277.95
Rings: $35.95
Heads: $0.00
Total: $750.06
Remaining: $749.94
 
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#4 ·
That sounds like a pretty good build to me. you'll have plenty of power. I have used the vortec heads and like them for this type of build. You will need to check that they will handle that much lift. Don't go by magazine here-say. Measure them. You might need upgraded valve springs too if you plan to run it hard. I bought the cutter tool from Comp Cams and turned down the valve guide boss and enlarged the spring seat using the tool and a drill and WD-40.
 
#7 ·
Regarding the measurement, you have it correct. It is a little tricky to measure with calipers, but you should be able to do it. A dial indicator and magnetic base will work too. 0.060" is generally the accepted clearance for retainer to guide and also coil bind. I have done the "ghetto grind" on the retainers to gain a little extra clearance. Just take the bottom of the retainer to the grinder and take 0.030" or so off. Detail it with a file and some sand paper......make sure all the burs are gone.

I have heard of guys running the springs without the dampers without issue. for a 5500 rpm engine, it would probably be ok, but i have personally never done it.

Tom
 
#9 ·
Dropped off stuff at the machinist's place today.

His list prices for the work are:
$70 for caustic soda bath
$160 for boring/honing
$125 for valve job and guide cutting

Didn't have a set price on inspecting and possibly grinding the crank or freeze plug or cam bearing install.

He used to do work for my dad back in the day. More than likely, these prices plus new rod, crank, and cam bearings will be what he charges me. He tends to make up prices; the more parts you buy from him, the cheaper the work is :laugh: Really cool old school engine builder.

We talked about balancing a bit. He said it's not really necessary, but that a lot of guys have it done any way, and he didn't have a solid opinion on whether I should have it done or not. He mostly does work for the bracket racers that race at Route 66, and doesn't build a lot of street engines. He was leaning more towards not doing it, as it's not typically done with rebuilds, but welcomed an extra $160.

The new pistons and pins are all within a tenth of a gram of each other. I'm reusing the stock rods (which should all be equally weighted), and the stock crank (which should already be balanced with its harmonic balancer).

What does JF say about balancing?
 
#10 ·
The main question is how do the new, hypereutectic, .030 over pistons compare to the old, cast, standard bore pistons? That is what your crank was originally balanced for.

Does he use a torque plate to bore and hone?


Shawn
 
#15 ·
Rods came today. Taking them to the shop tomorrow so he can balance everything.



Machinist sent the crank out to be ground. The mains were trash but the throws just needed polishing. The mains were so bad that they needed a 0.020" grinding.

Feels good to know that quality parts and quality work are going into this motor. Almost justifies spending all this money.

I want to file the rings myself. Can someone point me in the direction of a good and cheap ring grinder?
 
#16 ·
Picked everything up at the machine shop today. Looks awesome.

Few extras tacked on to the cost a bit. My crank was trash so I got a new one. One of the heads was warped a bit so the pair were taken 0.006" down for a clean up. One exhaust valve and guide were trash. Got all Clevite P series bearings from him. Used spiral locks on the pins instead of the clips the pistons came with.

I'll take some pics later.

Total cost for everything was $828. That brings me to:

Cam, lifters, locks, retainers, seals, springs: $359.23
Head gaskets: $53.98
Oil pump: $22.95
Pistons: $277.95
Rings: $35.95
Heads: $0.00
Connecting rods: $207.96
Shop work: $828
Total: $1786.02
 
#20 ·
Wow, they didn't put it back together for you? I got a price of 1800 for a complete rebuild and getting a ready to drop in motor when done. Other then that, looks great...
 
#22 ·


Been working on it when I find the time.

I have a question about the heads. One of them will not sit down over the dowels, on either side of the block. The head gaskets fit over the dowels just fine, and appears to line up correctly with the dowel holes on the heads. One end of the head will sit all the way down, but the other will not. This was a problem before everything went for machining. One of the heads was warped, and they were both given a cleanup cut. I was hoping this would fix the problem, but it hasn't. The dowels look fairly clean. Should I lap the dowel pins? Tap the head on with a mallet?
 
#23 ·
Don't tap on the heads!!! A similar problem was asked on hotrodders.com and the advise was to take the right size drillbit and clean up the hole on your heads. I think it was 3/16 but just check the sizing and try that out. Offset dowels are available if needed too but you should get by with cleaning up the hole. I'm doing a similar build myself with a 72 Z28 350 block. Haven't picked out heads yet but will go Vortec if my buddy decides not to sell me the Bowtie heads he has on the bench. Vortec heads vary in clearance because a lot of the valve guides are not seated all the way, I've read to take a socket and lightly tap them down to seat them all the way down. Most are advertised as good to .475 lift. I'm going with the Comp cams extreme energy 4x4 4262 cam. It has a decent lumpy idle but a sick torque curve from idle to 5500. I have .040 over pistons, 4 valve reliefs and a 9.7:1 compression ratio with 64cc Vortecs. I didn't know Comp cams sells a small tool to machine the valve guides at home. I think I prefer to have the machine shop put their name on that one and tell me the spring retainers are going to clear the guides for sure!
 
#24 ·
Alright, I'll take a look at the holes tomorrow. To the eye, they appear round and undamaged. I recall that one head was a pain in the *** to get off the donor motor. Might be the same one that is causing problems now.

My machinist was going to cut the guides down, but he determined that I didn't need to after the valve job and shimming and with the new springs and retainers. He said that I was good to around .500 lift. He builds stock car motors with Vortecs all the time, so I'm going to trust his judgement on that. He also talked me out of screw in studs, since I'm not running guideplates, and this is a 5500rpm redline motor.

Also, tapered aluminum ring compressors are your friend. I've heard horror stories from my dad and a couple friends about the contraptions they used back in the day. I got the entire rotating assembly together in an hour and a half. If anyone is interested, my plastigage clearances were as follows:

Main bearings: 0.002"
Rear main bearing: 0.003"
Rod bearings: 0.0015"
End play: 0.005"

The short block breaks loose at 30lb-ft. A little on the high side, but I'm attributing that to the thick rings. My machinist told me that some of the drag motors he builds will break over at 7lb-ft. Of course, those are running super trick plasma rings and super slick hones.
 
#32 ·
Can I please get some info on that alternator bracket/lolipop. I have the heads with no front bolt holes and my setup now is less than ideal, I like the looks of that setup.
 
#28 ·
These are just my questions. Not trying to be a jerk. I have done a lot of hot rodding over the years. What gear are you going to run and size tires? Your cam is not that big. The 2500 might be a little much and you could have power loss through the converter. The cam with you intake and q-jet should have good low end power. What heads do you have 461,462 or 291? Looks great. What make are the headers?
John
 
#30 ·
What gear are you going to run and size tires? Your cam is not that big. The 2500 might be a little much and you could have power loss through the converter. The cam with you intake and q-jet should have good low end power. What heads do you have 461,462 or 291? Looks great. What make are the headers?
John
Gears are 3.73 with 35's.

2500 stall is what Comp told me to run. Peak horsepower should be around 360@5000, peak torque should be around 400@4000.

It's more of a mid-range motor than low end, but it should still be putting out more low end than the motor had before.

Headers are Advance Adapters block huggers. I don't know if I'd call them headers, more like "tubular manifolds". I'll switch to shorties once it's on the road and ready to have the exhaust work done.

Heads are 062 Vortecs. Used to have 882 smoggers.

Foundrydude said:
Good build

2 cents from a guy who's done a lot of similar builds. With that much cam your stock Qjet is going to come up lean in the midrange and cost a bunch of power/torque. The best way to address it is to convert to an adjustable enrichment circuit like all the aftermarket performance Qjets use.

Also if that's the original camaro balancer, ditch it now before it slips in a few thousand miles. They all do at this age when put on anything that's run WOT. The elastomer is just too old and shrunk down and was probably oil soaked for ten years before it came out of the camaro. If it's the suburban head-donor balancer you might be OK.

Good luck with the truck!
I've put a lot of work into that Q-Jet to accommodate the cam.

Idle tubes drilled to 0.037", Upper idle air bleeds drilled to 0.050", Lower idle air bleeds drilled to 0.070", Main air bleeds to 0.070", jets are 0.072", rods are 0.044".

Went on the conservative side for now. I want to get it idling decently first. Then I can check manifold vacuum and make changes to the idle and part-throttle mixtures. I can screw around with the secondaries later.

My machinist and most of my friends cringed when I told them I was rebuilding and modding the Q-Jet. I don't think it's that complicated to get them tuned correctly if you have the correct literature and some motivation. The center-hung float makes them arguably the best carb for off-roading. I only have about $100 of parts in it too.

The balancer is the stock '77 Chevy balancer (I'm assuming). Machinist took a look at it and said it was all right, and shouldn't slip. I was worried about that too. I scored it across the hub and the weight to check if it slips in the future.
 
#29 ·
Good build

2 cents from a guy who's done a lot of similar builds. With that much cam your stock Qjet is going to come up lean in the midrange and cost a bunch of power/torque. The best way to address it is to convert to an adjustable enrichment circuit like all the aftermarket performance Qjets use.

Also if that's the original camaro balancer, ditch it now before it slips in a few thousand miles. They all do at this age when put on anything that's run WOT. The elastomer is just too old and shrunk down and was probably oil soaked for ten years before it came out of the camaro. If it's the suburban head-donor balancer you might be OK.

Good luck with the truck!
 
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