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Discussion Starter #1
I bought a 350 long block in the past off craigslist, long story short, it never seemed to sound or run quite right, so I tore it down to find all the bearings were demolished by a little bit of sand (this wont happen again), and the driver side head was warped. Heads casting number showed that they were crack prone, already had other heads ordered up waiting for them to crack.

I have a few basic parts that I already have for the new engine:
------------------------------------------------------------------------
Heads:
-Comp Cams Aluminum heads with .650 grade lift springs, 2.02/1.90 valves 64cc chamber, 190cc runners, with 3/8 studs and guide plates (brand new).
-Fel Pro 1003 Head gaskets .041 compressed (brand new).
-ARP Head Bolts.

Valve Train:
-1.5 stainless full roller rockers (brand new).
-Engle EP-26/28 .520lift with 1.5 rockers, 288 advertised duration, 108 LSA, with hydraulic lifters (off old engine, looks brand new).

Intake:
-Holley 600cfm Double Pumper, mechanical secondaries/choke Aluminum Fuel Bowls, with aluminum heat sheild.
-Holley Street Dominator Open Plenum Aluminum Intake.

Going to be in a 1952 GMC long-bed pickup, manual 4spd. Saginaw tranny with Hurst shifter, Posi-traction rear (unknown gearing guessing in the low 3's), no power ANYTHING, no ac or heater. Dual 2.5in exhaust with the old cherry bomb long glass packs. Aluminum plate instead of an oak bed, apparently weighs total, less than 3500 pounds.
------------------------------------------------------------------------


Here's where the interesting stuff begins, I decided that I should just get a new short block since I do not have all the required tools other than the normal socket wrenches and torque wrenches to completely rebuild from a bare block after the machine shop, and I need something working very soon.

I not only want to use the parts that I have already bought, but I am nearly forced to by my budget of $2000. I have been browsing around after doing lots of research and have not found much of any engine blocks that will work for me.

#1: my cam states that it requires 10 - 10.5:1 compression. Blocks are either less than 9.5:1 or greater than 11:1 compression
#2: In order to get proper quench (.040), the deck clearance must be flush with the piston since my head gasket is already at .041!
#3: 383's seem to have the compression that I need, but all so far only include flexplates and no balanced flywheels for manual transmission cars.

My worst fear is to have to resort to a 190HP stock GM crate 350, crappy gas mileage and crappy power is not appealing when there are lots of big long hills and lots of trash can muffled hondas lol.

Any thoughts, opinions, advice? How can I use the parts that I already have within my budget most effectively? All comments are welcome, and all help is greatly appreciated! :thumbup:
 

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Discussion Starter #2 (Edited)
The old block is a 2-bolt main 22,000 miles, unknown deck clearance, bored to .060, there are quite a few scratches in some cylinders, which I am afraid I will be unable to have safely bored any farther. :(

There are a few engine kits, what do you think about them?
 

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Discussion Starter #3
Still has some cross hatch in some cylinders, but there are scratches from top to bottom, sounds like a new block is the path to start then!
 

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Discussion Starter #4
looks like things are moving forward :), I found a reputable private seller on ebay with a short block that was willing to respond to me with some much needed info! FINALLY, what a rare breed of a seller in this day and age!

So he has two 350 short blocks, one that will give me .030 quench, and another that will give me .040 quench, and bored .040 over. The .030 quench block will give me 10.56:1 compression, and the .040 quench block will give me 10.3:1 compression.

When I get the short block, ill be sure to inspect and double check his work.

Even though ill have better quench, with aluminum heads and 91 octane, would 10.56:1 compression still be too much? It comes with a cam, but I might use my own since it has 288 advertised duration, which apparently could help with lowering the dynamic compression.

I was reading in other places, and apparently with aluminum heads, anything below 11:1 should be ok, anyone have experience in this?
 

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Discussion Starter #5
thanks, looks like ill be ok at 10.56:1 then.

-Engle EP-26/28 .520lift with 1.5 rockers, 288 advertised duration, 108 LSA, with hydraulic lifters (off old engine, looks brand new).
 

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I bought a 350 long block in the past off craigslist, long story short, it never seemed to sound or run quite right, so I tore it down to find all the bearings were demolished by a little bit of sand (this wont happen again), and the driver side head was warped. Heads casting number showed that they were crack prone, already had other heads ordered up waiting for them to crack.

I have a few basic parts that I already have for the new engine:
------------------------------------------------------------------------
Heads:
-Comp Cams Aluminum heads with .650 grade lift springs, 2.02/1.90 valves 64cc chamber, 190cc runners, with 3/8 studs and guide plates (brand new).
-Fel Pro 1003 Head gaskets .041 compressed (brand new).
-ARP Head Bolts.

Valve Train:
-1.5 stainless full roller rockers (brand new).
-Engle EP-26/28 .520lift with 1.5 rockers, 288 advertised duration, 108 LSA, with hydraulic lifters (off old engine, looks brand new).

Intake:
-Holley 600cfm Double Pumper, mechanical secondaries/choke Aluminum Fuel Bowls, with aluminum heat sheild.
-Holley Street Dominator Open Plenum Aluminum Intake.

Going to be in a 1952 GMC long-bed pickup, manual 4spd. Saginaw tranny with Hurst shifter, Posi-traction rear (unknown gearing guessing in the low 3's), no power ANYTHING, no ac or heater. Dual 2.5in exhaust with the old cherry bomb long glass packs. Aluminum plate instead of an oak bed, apparently weighs total, less than 3500 pounds.
------------------------------------------------------------------------


Here's where the interesting stuff begins, I decided that I should just get a new short block since I do not have all the required tools other than the normal socket wrenches and torque wrenches to completely rebuild from a bare block after the machine shop, and I need something working very soon.

I not only want to use the parts that I have already bought, but I am nearly forced to by my budget of $2000. I have been browsing around after doing lots of research and have not found much of any engine blocks that will work for me.

#1: my cam states that it requires 10 - 10.5:1 compression. Blocks are either less than 9.5:1 or greater than 11:1 compression
#2: In order to get proper quench (.040), the deck clearance must be flush with the piston since my head gasket is already at .041!
#3: 383's seem to have the compression that I need, but all so far only include flexplates and no balanced flywheels for manual transmission cars.

My worst fear is to have to resort to a 190HP stock GM crate 350, crappy gas mileage and crappy power is not appealing when there are lots of big long hills and lots of trash can muffled hondas lol.

Any thoughts, opinions, advice? How can I use the parts that I already have within my budget most effectively? All comments are welcome, and all help is greatly appreciated! :thumbup:
comp cams heads thats a new one
 

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I bought a 350 long block in the past off craigslist, long story short, it never seemed to sound or run quite right, so I tore it down to find all the bearings were demolished by a little bit of sand (this wont happen again), and the driver side head was warped. Heads casting number showed that they were crack prone, already had other heads ordered up waiting for them to crack.

I have a few basic parts that I already have for the new engine:
------------------------------------------------------------------------
Heads:
-Comp Cams Aluminum heads with .650 grade lift springs, 2.02/1.90 valves 64cc chamber, 190cc runners, with 3/8 studs and guide plates (brand new).
-Fel Pro 1003 Head gaskets .041 compressed (brand new).
-ARP Head Bolts.

Valve Train:
-1.5 stainless full roller rockers (brand new).
-Engle EP-26/28 .520lift with 1.5 rockers, 288 advertised duration, 108 LSA, with hydraulic lifters (off old engine, looks brand new).

Intake:
-Holley 600cfm Double Pumper, mechanical secondaries/choke Aluminum Fuel Bowls, with aluminum heat sheild.
-Holley Street Dominator Open Plenum Aluminum Intake.

Going to be in a 1952 GMC long-bed pickup, manual 4spd. Saginaw tranny with Hurst shifter, Posi-traction rear (unknown gearing guessing in the low 3's), no power ANYTHING, no ac or heater. Dual 2.5in exhaust with the old cherry bomb long glass packs. Aluminum plate instead of an oak bed, apparently weighs total, less than 3500 pounds.
------------------------------------------------------------------------


Here's where the interesting stuff begins, I decided that I should just get a new short block since I do not have all the required tools other than the normal socket wrenches and torque wrenches to completely rebuild from a bare block after the machine shop, and I need something working very soon.

I not only want to use the parts that I have already bought, but I am nearly forced to by my budget of $2000. I have been browsing around after doing lots of research and have not found much of any engine blocks that will work for me.

#1: my cam states that it requires 10 - 10.5:1 compression. Blocks are either less than 9.5:1 or greater than 11:1 compression
#2: In order to get proper quench (.040), the deck clearance must be flush with the piston since my head gasket is already at .041!
#3: 383's seem to have the compression that I need, but all so far only include flexplates and no balanced flywheels for manual transmission cars.

My worst fear is to have to resort to a 190HP stock GM crate 350, crappy gas mileage and crappy power is not appealing when there are lots of big long hills and lots of trash can muffled hondas lol.

Any thoughts, opinions, advice? How can I use the parts that I already have within my budget most effectively? All comments are welcome, and all help is greatly appreciated! :thumbup:
Comp cams doesn't make cylinder heads.

If you build an engine w/too much compression, you can run out of octane unless you want to run it on race gas or E85. So do not be tempted to run 11:1 on pump gas. Running a big cam only partially crutches the need for octane- the quench distance has to be spot on, and a big cam also requires a low rear gear, and unless you have an OD tranny to crutch that up, you'll be miserable driving any distance with =/> 4.56:1 rear gears.

In a truck I suspect strongly that you'll be a lot happier w/a 9-9.5:1 compression engine and a cam to match. If the lifters were mixed up and not placed exactly back on the same lobe they came from originally, the cam and lifters are junk, anyway.
 

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Discussion Starter #10 (Edited)
I found this to be an excellent read during my research: Racing Engine, How to tips

cobalt brought up some good points, if it is a truck, then it should have the ability to pull something, even though I VERY highly doubt I will EVER pull anything above 500 pounds, you never know.

For a truck engine as a general rule, is it 9-9.5:1 for iron heads, and 10-10.5:1 for aluminum heads? I read that running aluminum heads allows you to increase compression by one point. I'm thinking that it would also be a good added insurance to run .035 quench since I do not expect to ever rev above 6000.

thanks for the good advice cobalt :thumbup:
 

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Get rid of the double pumper and go with a vac secondary 750. It will perform better and won't crap the oil up when your cruising around town. Plugs will last longer too.
 

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iron always makes more power than alum..
alum is just easier to cast..
nascar engines make over 80 hp with iron over alum.. but are a one race deal.. when they qualified and pulled engines then ran another in the race iron was the ticket.. but where a one and done part..
 

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Discussion Starter #13
iron always makes more power than alum..
alum is just easier to cast..
nascar engines make over 80 hp with iron over alum.. but are a one race deal.. when they qualified and pulled engines then ran another in the race iron was the ticket.. but where a one and done part..
That is interesting, you would think that the added compression, cooling, and reduction in weight would have made all the difference.
 

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That is interesting, you would think that the added compression, cooling, and reduction in weight would have made all the difference.
thats the thing.. today.. people get the idea alum makes more because they run higher compression..
but a 12 to 1 iron headed and the same engine with alum heads..
if both the same in everyway other than heads casting material..
the iron wins everytime..
if you got the fuel..
e85 if they'd cast say dart pro ones in iron.. would rock
 

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iron makes more power hands down.
alum is easier to cast/machine/etc and why they use it..
pore the same heads in both, iron will win everytime
heat = power, alum transfers it, iron holds it..
with a fuel that not pre ign. iron all the way..
r09 engines heads where taken by nascar that where iron.. because the walked over the field
team fined 100k
 

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I found this to be an excellent read during my research: Racing Engine, How to tips

cobalt brought up some good points, if it is a truck, then it should have the ability to pull something, even though I VERY highly doubt I will EVER pull anything above 500 pounds, you never know.

For a truck engine as a general rule, is it 9-9.5:1 for iron heads, and 10-10.5:1 for aluminum heads? I read that running aluminum heads allows you to increase compression by one point. I'm thinking that it would also be a good added insurance to run .035 quench since I do not expect to ever rev above 6000.

thanks for the good advice cobalt :thumbup:
I would call your estimate of "9-9.5:1 for iron heads, and 10-10.5:1 for aluminum heads", safe. I would not, however, want you to go any closer than 0.040" quench. 0.035" leaves NO room for error on the part of the machinist or the dimensions of the parts or even a missed shift or broken driveline part, there's nothing of any real substance to be gained from the extra 0.005", and the downside can be expensive.

While it's true you can usually get away w/more compression using aluminum heads, this is only because aluminum sheds heat easier into the cooling system. There are no free lunches- if you build w/alum. heads, the added compression is needed just to stay even w/an iron head- not that aluminum magically allows you to run more compression. I don't much care for aluminum heads on a SBC daily driven vehicle myself, I like good ol' cast iron. That's not to say the good aluminum heads aren't good- they are- but you do pay for the privilege.

In the same vein, I also never build a street engine right on the edge, compression-wise, either. The general rule of thumb on compression is one point- like going from 9:1 to 10:1- will net you about 4% more power, all else being equal. Now, that IS 16 hp on a 400 hp engine, so isn't exactly insignificant, but the down side to the added compression can be a huge loss of power if you misjudge things and you end up needing to retard the total timing from what gives you the best power- just so the engine doesn't detonate. And it has other downsides as well like less tolerance to a bad tank of fuel, or something that causes the coolant temp to rise past normal. At least in the last two cases you can stop, get out, and turn the distributor to lower the timing to limp home w/o ruining the engine- as long as you caught it soon enough.

My bottom line is: There have been a LOT of VERY strong running SBC 350/360s built using 9-9.5:1 CR. A properly spec'ed and assembled engine w/that CR can expect to make more power than you can safely use on the street. A racing engine is another animal altogether and the two (racing engine on the street) seldom meet happily in the middle, in my experience. Again, that's not to say there aren't 10:1-plus iron head or 11:1-plus aluminum head engines being driven on the street every day, w/o issue. But it IS to say that if you choose to run on the edge, it can bite you.

So I cannot in good conscience advise anyone to build a 11:1 aluminum or 10:1 iron head engine for street duty. When the parts on hand absolutely HAVE to be used, sometimes this means compromises must be made- I understand this. But if at all possible, hedge your bet to the safer side rather than the "faster" side.

Good luck.
 

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Some things I forgot to say. Main thing: Stick to the fundamentals.

Insist on a torque plate final hone. A good, round cylinder w/a piston that has the correct piston to wall clearance, along w/the correct ring end gaps will do as much for performance as a LOT of other "racing" tricks. What guys fail to realize is, while a loose piston to bore clearance may have less friction, the rocking motion this allows causes the ring seal to go away.

Follow the manufacturers specs for piston clearance, ring end gap, etc. Measure the piston where the manufacturer says to measure it.

Use a three angle valve job. Backcutting the valves is sometimes a cheap way to increase flow where it'll help on a day-to-day basis (look at what GM did w/the Vortec valves- they do NOTHING "just because" :mwink:).

Break in the cam correctly.

There are other things but these are fairly important IMHO.
 

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Some things I forgot to say. Main thing: Stick to the fundamentals.

Insist on a torque plate final hone. A good, round cylinder w/a piston that has the correct piston to wall clearance, along w/the correct ring end gaps will do as much for performance as a LOT of other "racing" tricks. What guys fail to realize is, while a loose piston to bore clearance may have less friction, the rocking motion this allows causes the ring seal to go away.

Follow the manufacturers specs for piston clearance, ring end gap, etc. Measure the piston where the manufacturer says to measure it.

Use a three angle valve job. Backcutting the valves is sometimes a cheap way to increase flow where it'll help on a day-to-day basis (look at what GM did w/the Vortec valves- they do NOTHING "just because" :mwink:).

Break in the cam correctly.

There are other things but these are fairly important IMHO.
plate hone, with bolts or studs being used on engine, and main caps torques if poss.
 

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Discussion Starter #19
Ok, with a quench of .040 I will have 10.3:1 compression.

Bore: 4.040 (diameter)
Stroke: 3.48
Cylinder Head Volume: 64
Effective Dome Volume: 6
Use (-) for Dome and (+) for Dish.
Deck Clearance: .025
Compressed Gasket Thickness: .015
Number of Cylinders: 8
Compression Ratio : 10.31 : 1
Total Displacement (in.3) : 356.88
Total Displacement cc's : 5850.49

2 FEL Pro Head Gaskets Rubber Coated Steel Shim 4 100" Bore 015" Comp | eBay (head gasket)
New Small Block Chevy 350 IMCA Claimer Racing Oil Pan | eBay (oil pan)
PRW SBC 305 350 Chevy Sportsman 8" Polished Harmonic Balancer | eBay (damper)
350 Chevy Short Block Assembly High Performance w Forged Pistons | eBay (they may be in the build process as we speak, they are willing to do any deck height I choose)

I can either use that .015 gasket (sounds too thin for aluminum heads) or I can tell them to deck the block to .000 for my Fel Pro 1003 .041 gasket.
 

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Discussion Starter #20 (Edited)
Got an interesting email from the builder.

"Just left the shop and wanted to run some things by you. The only 79 down 4 bolt at the shop is a .060 over, let me know if that's alright. Also, the owner (Barry) said that with the stock block, crank, etc. He can only guarantee a 0" - .0035" margin between cylinders on zeroing the block. Shoot me a note when you get a chance."

Usually I would think that a .0035 margin as insignificant since it is such a small number. Is that good, bad, or ugly?

I asked him if .060 will be the final bore, if it is, I don't see it as a significant issue, I have a triple pass aluminum radiator, high-flow aluminum water pump, and I assume aluminum heads will help out a tad too.
 
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