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trillobite 12-06-2012 07:54 PM

brainstorming an engine build
 
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:

hcompton 12-06-2012 08:04 PM

Is the bore bad. Get a 383 kit it will replace the crank pistons and rods for about 800 bucks.

If the block is trashed just get a good one from the junk yard or locally just make sure you can look at it first. Good blocks are not hard to find.

Some of the crate motors are so poorly built they are not even worth the time. Inwould build my own after some of the enginesi have seen i am not going crate motor again unless its all 100% new engine.

trillobite 12-06-2012 08:10 PM

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?

hcompton 12-06-2012 08:17 PM

Quote:

Originally Posted by trillobite (Post 1620023)
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. :(

Nope if the cross hatch is gone and cylinder scratched top to bottom then its trash. Grab another block look for an 010 in the last digits they are usally a little better and higher chances of getting a four bolt. But two bolt blocks are fine and dont fail below 500 hp they just dont last as long.

trillobite 12-06-2012 08:20 PM

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!

trillobite 12-08-2012 05:26 PM

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?

hcompton 12-08-2012 06:10 PM

11:1 can be made to work but only with proper sized cam and tuning. If its not setip right it will be a rattle trap. Im sure you have done some research already.

But with 11:1 and a cam like a comp 294s or BMT you will be fine. Small cams may lead to some issues.

trillobite 12-08-2012 06:46 PM

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).

gearheadslife 12-08-2012 07:39 PM

Quote:

Originally Posted by trillobite (Post 1620015)
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

trillobite 12-08-2012 09:19 PM

hahaha oups, thanks for pointing that out, strike that.
They are procomp heads. :rolleyes:

gearheadslife 12-08-2012 11:19 PM

g.m. vortec '96-02 replacement crate 2000.oo
300+ hp all day long.. 350 if you change the cam..

cobalt327 12-08-2012 11:31 PM

Quote:

Originally Posted by trillobite (Post 1620015)
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.

trillobite 12-09-2012 04:32 PM

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:

vht 12-09-2012 05:23 PM

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.

gearheadslife 12-09-2012 05:25 PM

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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