[Junkyard Dog]

Originally Posted by Tom Vaught

Try to find a 1967 2 bolt main block, (not drilled for 4 bolt mains), put a set of splayed caps on the block, a 4.0" Good forged crank, and a decent set of heads with a Boosting Device and you will have great durability and lots of HP.

Tom V.

I am starting with a 1973 455 block.

Some lowlife scumbag POS stole my 4.21" crankshaft, so it looks like I get a bit of a clean sheet on choosing the stroke.

[v869tr6]

Scat forged crank, eagle rods with upgraded bolts, Ross pistons with I think a 40 cc dish and heavy wall pins.
Out of the box 87cc E heads with better exhaust valves, just installed insert washers so I don't have to battle with the studs. Pull Evans coolant from the back of the heads up to the crossover and pull coolant from the intake side of both heads back to the radiator.
Molly rings, Cometic head gaskets, super victor efi, 160lb Ford injectors, home made fuel rails.
Cam-motion flat tappet hyd. cam 232/226 at around 0.477 lift Butler heavy wall 5/16
pushrods, Comp Cams roller tip 1.52 rockers
And a TV7512 Garrett with a cast 91mm compressor wheel, this turbo isn't the greatest as the compressor is to large for the turbine even with the exhaust wheel clipped and a 1.23 exhaust housing, but it's molded into the hood.

[frbformula]

So it looks like I have nailed down the short block im going to be building:

1969 400 block
splayed 4 bolt billet main caps
Mega brace
all ARP studs
Scat 4" crank
6.8" rods
Ross pistons
I will shoot for 8.5-9.0 compression

My next decision I would like to tackle is whether or not to dry deck the block and what effect do that have on street driving. Any input will be appreciated

[Tom McQueen]

Originally Posted by frbformula

So it looks like I have nailed down the short block im going to be building:

1969 400 block
splayed 4 bolt billet main caps
Mega brace
all ARP studs
Scat 4" crank
6.8" rods
Ross pistons
I will shoot for 8.5-9.0 compression

My next decision I would like to tackle is whether or not to dry deck the block and what effect do that have on street driving. Any input will be appreciated

--------------------------------------------------------------------------------------

If you really want bullet proof talk to SME about anodized pistons.

[Junkyard Dog]

Originally Posted by v869tr6

Ross pistons with I think a 40 cc dish and heavy wall pins.

Wow. I did not even know they could take 40 cc out of a piston!

[v869tr6]

Originally Posted by Junkyard Dog

Wow. I did not even know they could take 40 cc out of a piston!

Doesn't leave that much around the outside top of the piston about 3/8ths wide ring.
If I ever need new pistons again I plan to just have a set made with a completely flat top and drop the pistons down the hole. That will keep the top ring land nice and meaty, no thin spots for the heat to get to and start lifting ring lands. Might even save a engine from a short term, major tuning issue or give the engine a chance if I get crazy enough to try a standing 1/2 mile. Turned some of my oil soaks in my belly pan into plastic from two back to back road pulls. Guess those glowing pipes are hot.LOL

[blueghoast]

Originally Posted by v869tr6

Scat forged crank, eagle rods with upgraded bolts, Ross pistons with I think a 40 cc dish and heavy wall pins.
Out of the box 87cc E heads with better exhaust valves, just installed insert washers so I don't have to battle with the studs. Pull Evans coolant from the back of the heads up to the crossover and pull coolant from the intake side of both heads back to the radiator.
Molly rings, Cometic head gaskets, super victor efi, 160lb Ford injectors, home made fuel rails.
Cam-motion flat tappet hyd. cam 232/226 at around 0.477 lift Butler heavy wall 5/16
pushrods, Comp Cams roller tip 1.52 rockers
And a TV7512 Garrett with a cast 91mm compressor wheel, this turbo isn't the greatest as the compressor is to large for the turbine even with the exhaust wheel clipped and a 1.23 exhaust housing, but it's molded into the hood.

That's impressive, What seat pressure as I'm running a hyd flat tappet to.

Thanks GT.

[bendutro]

Originally Posted by Tom Vaught

So tell me who you are:

I personally have been playing with Pontiac Traditional Engines for 50 Years.
<snip>
just saying.

Tom Vaught

Sounds like you have depth of experience. I'm not swinging my johnson and saying I know better, but the world is full of self-proclaimed experts. The real authorities can bring the tech and back up their assertions with data. That's all I was getting at.

[Tom Vaught]

Just enough experience to know that:

1) Everyone has a "different budget"

2) Everyone has "different objectives"

3) Everyone has "experience levels" but most everyone typically wants to learn new things.

If you want data on 4 valve engines with 3.5 liters that can make 1000+ hp with a pair of turbochargers on a $400,000 Ford GT, I might be able to find the info (data) for you.

Just because I have that data does not help the guy with a Grand Prix with cast iron heads and a set of long branch headers looking for a hydraulic camshaft spec. That part comes with experiences besides the Dyno and data.

I have no desire to run a dyno test for someone on their Grand Prix, just so I can back up a post with some data. You play with the stuff long enough and talk to enough people and you can hit the number pretty close (as far as track times), without that data.

But the original post you made was RPM.

The combination is what does or does not come apart at the end of the day. (Blow up).

Example: Mazda Speed Engine. 3 engines All with over 1500 hours of dyno testing under HARD CONDITIONS. None made it very far past 1600 hours because the parts "just got tired" and "gave up" (and exited the block).

So I have Data on all three engines but common sense says maybe it is time to change the rods after 1600 hours of dyno testing? I have lots of data on those engines.

Tom V.

ps Just those 3 engines was 4800 hours on the dyno. You think you know a little bit about 6 times in your life and then you start over with "I really did not know very much at all about this deal". I learn every day.

[v869tr6]

Originally Posted by blueghoast

That's impressive, What seat pressure as I'm running a hyd flat tappet to.

Thanks GT.

I could be wrong but I think they are at about 126 on the seat

[LPI]

If you want a reliable cost effective build then this is a good recipe which has been proven many times over:

Stock 3" main block 2 bolt w/ mods or splayed 4 bolt caps, stay away from straight bolt 4 bolt caps, it weakens the main bearing webbing.

Scat forged 3.75" or 4.00" stroke crank, single key way unless running a cog belt (supercharger applications)

Two reasons, one the overlap of the main to rod journals diameters and a boosted engine makes torque lower on the rpm curve so having NA type torque from a large stroke is not necessary.

Pro Race or BHJ 4 bolt "stock" style balancer or the ATI 3 bolt (again this is more important on a supercharged motor then a turbo motor but still important)

This is a must, a proper harmonic balancer bolt, tightened to the proper torque load. Using anything but will cause a failure. If you need to use a mandrel buy a proper mandrel that bolts on top of the pulleys. Never use a long bolt to hold other items along with the harmonic balancer.

Eagle 6.635" BBC connecting rods with ARP 2000 rod bolts (this is the least expensive readily available rod to match readily available piston CH designs)

Ross, CP, or any other custom forged dished piston with top ring land down .300" to .350" standard ring pack 1/16", 1/16", 3/16" Fully skirted

Thick wall tool steel wrist pins (Weight is not the enemy in a boosted engine)

Proper modifications to the cylinder head quench area again in our opinion and experience is a must for reliability and longevity

We offer the only "zero" growth tested hard coat anodized piston for three reasons, ring lands, pins and crown.

Speed Pro Hell fire rings or Engine Pro nitro black PVD style (gaps very important)

Engine Pro "hi load" BBC rod bearings, specifically designed for boost

Speed Pro main bearings

Some light engine oiling mods for the block

Our grooved camshaft bearings for the higher load spring pressures

Our cast AB low friction camshaft thrust plate

Our hi volume hi flow inlet oil pump (we now have a 7" deep stock pan pickup available) Thanks Ed!

A boost specific camshaft preferably with the LS firing order (Double swap)

A proper boost retard timing system

A boost specific fuel delivery system and carb or efi system. The carburetors from C&S (who we work with) has most all of the Pontiac parameters and can wet flow a carb specific to your application for a bolt on ready to run unit.

For carbureted systems we prefer the single plane Hurricane intake manifold

If running aluminum cylinder heads then adding the stepped cylinder head bolt washers is a must.

We prefer Cometic MLS head gaskets specific for boost applications

We have our own scientifically tested clamp load and torque procedure to ensure a good clamp load for boosted engines.

This is not rocket science and we are not here to sell anyone anything contrary to some beliefs.

The goal is to produce a positive successful and reliable outcome for the customer with a boost build.

Just like SME with BBC's and Fords we do this everyday with BOP's. We see both sides of the coin, the positive outcomes and the negative starts that we try to the best of our ability to aid and repair. If you are close to Michigan then by all means please call SME and talk to Alex, they will not steer you wrong.

I champion you for asking questions first. In the end you are the customer and you are going to buy the parts that you feel most comfortable with.

It is no different then buying a Holley type carburetor, some buy Holley, some buy Barry Grant and others with buy a Pro Systems, it is what you decide and are comfortable with.

Our job is to give you the facts and the experience as to what works over time and produces the most cost effective and most reliable outcome.

If you are looking for maximum Hp then I would stop with a stock block and look at a small bore aftermarket blocks.

We feel very confident in a boosted atmosphere (yes pun intended...LOL) a stock 400 block can handle loads up to 1200 Hp, 1000 very reliably.

Tune up is also key which for any engine is a must. This is just a given.

Again none of these parts are exotic, nothing you cannot get from almost any vendor, supplier or machine shop.

I champion all the guys that have stepped up to boost and have created their own successful stock block projects.

As Corky Bell spells out in his books..."Attention to detail...and common sense will produce the most reliable and enjoyable outcome"

As I say, questions cost nothing, buying parts twice cost money and breeds frustration.

If all we do at the end of the day is give you reliable fact proven and tested information then our job is complete. If you want to buy something from us or ask our opinion on what you already have we will give you an unbiased assessment based on our knowledge, experience and real world testing.

The outcome is the only thing that matters.

[BruceWilkie]

Originally Posted by LPI

If you want a reliable cost effective build then this is a good recipe which has been proven many times over:

Stock 3" main block 2 bolt w/ mods or splayed 4 bolt caps, stay away from straight bolt 4 bolt caps, it weakens the main bearing webbing.

Scat forged 3.75" or 4.00" stroke crank, single key way unless running a cog belt (supercharger applications)

Two reasons, one the overlap of the main to rod journals diameters and a boosted engine makes torque lower on the rpm curve so having NA type torque from a large stroke is not necessary.

Pro Race or BHJ 4 bolt "stock" style balancer or the ATI 3 bolt (again this is more important on a supercharged motor then a turbo motor but still important)

This is a must, a proper harmonic balancer bolt, tightened to the proper torque load. Using anything but will cause a failure. If you need to use a mandrel buy a proper mandrel that bolts on top of the pulleys. Never use a long bolt to hold other items along with the harmonic balancer.

Eagle 6.635" BBC connecting rods with ARP 2000 rod bolts (this is the least expensive readily available rod to match readily available piston CH designs)

Ross, CP, or any other custom forged dished piston with top ring land down .300" to .350" standard ring pack 1/16", 1/16", 3/16" Fully skirted

Thick wall tool steel wrist pins (Weight is not the enemy in a boosted engine)

Proper modifications to the cylinder head quench area again in our opinion and experience is a must for reliability and longevity

We offer the only "zero" growth tested hard coat anodized piston for three reasons, ring lands, pins and crown.

Speed Pro Hell fire rings or Engine Pro nitro black PVD style (gaps very important)

Engine Pro "hi load" BBC rod bearings, specifically designed for boost

Speed Pro main bearings

Some light engine oiling mods for the block

Our grooved camshaft bearings for the higher load spring pressures

Our cast AB low friction camshaft thrust plate

Our hi volume hi flow inlet oil pump (we now have a 7" deep stock pan pickup available) Thanks Ed!

A boost specific camshaft preferably with the LS firing order (Double swap)

A proper boost retard timing system

A boost specific fuel delivery system and carb or efi system. The carburetors from C&S (who we work with) has most all of the Pontiac parameters and can wet flow a carb specific to your application for a bolt on ready to run unit.

For carbureted systems we prefer the single plane Hurricane intake manifold

If running aluminum cylinder heads then adding the stepped cylinder head bolt washers is a must.

We prefer Cometic MLS head gaskets specific for boost applications

We have our own scientifically tested clamp load and torque procedure to ensure a good clamp load for boosted engines.

This is not rocket science and we are not here to sell anyone anything contrary to some beliefs.

The goal is to produce a positive successful and reliable outcome for the customer with a boost build.

Just like SME with BBC's and Fords we do this everyday with BOP's. We see both sides of the coin, the positive outcomes and the negative starts that we try to the best of our ability to aid and repair. If you are close to Michigan then by all means please call SME and talk to Alex, they will not steer you wrong.

I champion you for asking questions first. In the end you are the customer and you are going to buy the parts that you feel most comfortable with.

It is no different then buying a Holley type carburetor, some buy Holley, some buy Barry Grant and others with buy a Pro Systems, it is what you decide and are comfortable with.

Our job is to give you the facts and the experience as to what works over time and produces the most cost effective and most reliable outcome.

If you are looking for maximum Hp then I would stop with a stock block and look at a small bore aftermarket blocks.

We feel very confident in a boosted atmosphere (yes pun intended...LOL) a stock 400 block can handle loads up to 1200 Hp, 1000 very reliably.

Tune up is also key which for any engine is a must. This is just a given.

Again none of these parts are exotic, nothing you cannot get from almost any vendor, supplier or machine shop.

I champion all the guys that have stepped up to boost and have created their own successful stock block projects.

As Corky Bell spells out in his books..."Attention to detail...and common sense will produce the most reliable and enjoyable outcome"

As I say, questions cost nothing, buying parts twice cost money and breeds frustration.

If all we do at the end of the day is give you reliable fact proven and tested information then our job is complete. If you want to buy something from us or ask our opinion on what you already have we will give you an unbiased assessment based on our knowledge, experience and real world testing.

The outcome is the only thing that matters.

Excellent post. I'll add that factory N cranks are quite strong HOWEVER they are more sensitive to harmonics. If you go that route do your homework and use common sense.

[Junkyard Dog]

Originally Posted by Junkyard Dog

I am starting with a 1973 455 block.

Some lowlife scumbag POS stole my 4.21" crankshaft, so it looks like I get a bit of a clean sheet on choosing the stroke.

So obviously I have 3.25 inch mains.

Do all the rest of the recommendations remain, or does this alter the advice?

[carbking]

I love these threads, and generally learn something, but have a question.

I can easily understand the desire for this level of HP on a trailered racecar; but at least two posters in this thread are asking for 800~900 HP on the street.

With no disrespect intended, have you ever driven a street vehicle with even half this much horsepower (not advertised, but real horsepower)? I know Dodge has its Hellcat, and Ford is reintroducing the GT-40; but these cars were designed by real engineers that have designed suspension, transmissions, tires, etc., etc., etc. to complement the vehicle, and still we read of those who overestimate their driving ability wrecking these cars. Other than maybe Montana or Nevada, where can you use 900 HP on the street?

Along with the ponies, how about the rest of the vehicle?

Jon.

[v869tr6]

Originally Posted by carbking

I love these threads, and generally learn something, but have a question.

I can easily understand the desire for this level of HP on a trailered racecar; but at least two posters in this thread are asking for 800~900 HP on the street.

With no disrespect intended, have you ever driven a street vehicle with even half this much horsepower (not advertised, but real horsepower)? I know Dodge has its Hellcat, and Ford is reintroducing the GT-40; but these cars were designed by real engineers that have designed suspension, transmissions, tires, etc., etc., etc. to complement the vehicle, and still we read of those who overestimate their driving ability wrecking these cars. Other than maybe Montana or Nevada, where can you use 900 HP on the street?

Along with the ponies, how about the rest of the vehicle?

Jon.

My car has a home built chassis, with a 4 link suspension and lower wishbone plus anti roll bars front and rear.
The boost over time function in my boost control almost makes the power usable.
With the car set for 800hp at the tire its just plane crazy, lots of fun but crazy. LOL

[JSPONT]

Originally Posted by carbking

I love these threads, and generally learn something, but have a question.

I can easily understand the desire for this level of HP on a trailered racecar; but at least two posters in this thread are asking for 800~900 HP on the street.

With no disrespect intended, have you ever driven a street vehicle with even half this much horsepower (not advertised, but real horsepower)? I know Dodge has its Hellcat, and Ford is reintroducing the GT-40; but these cars were designed by real engineers that have designed suspension, transmissions, tires, etc., etc., etc. to complement the vehicle, and still we read of those who overestimate their driving ability wrecking these cars. Other than maybe Montana or Nevada, where can you use 900 HP on the street?

Along with the ponies, how about the rest of the vehicle?

Jon.

The problem with boost is when you start out, you say I am only going to run 5 psi. Once you get that working you say, I'm going to try 8psi, then it just keeps going. With todays tires and suspension available, you would be surprised what you can hook. Even when you don't it is fun as hell!
A lot of street racing is done from a roll to help combat the h.p. levels of these cars. 50-150mph.
You can get a 455 to live on boost. 800-900 h.p. there are many doing it already.

[frbformula]

Carbking
I started this thread so i can assume im one of the posters your talking about. My car currently makes 600 to 700 at the crank N/A. The car has gone 10.84 spinning the tires. It has a full cage and harnesses, subframe connectors, all new rear suspension with caltracs, aluminum drive shaft, drive shaft loop and a motor plate. New front suspension will go in this winter. The car is all redone, its not a crappie car i want to put a bunch of power in. I do know that some people want all the hp but dont upgrade the rest of the car. In my case i dont believe that to be true. The car has been upgraded to handle the hp i want to put in it.

[BruceWilkie]

Carbking, the best part of a turbo'd vehicle is driveability. Driven normally its tame. No need for high numerical gear ratios either.(3.08-3.55 is fine, the turbo seems to like the loading).V869tr6 is doing great with 2.56's. Pretty good mileage too if you can keep your foot out of it. Bury the pedal and yes, it can become scary fast...however you can limit boost and adjust yourself and your vehicle for more as you go.


Besides, even a toyota mini van is too much power for some to be trusted with.

[BruceWilkie]

Originally Posted by Junkyard Dog

So obviously I have 3.25 inch mains.

Do all the rest of the recommendations remain, or does this alter the advice?

Seems there are more 455 turbo'd cars than 350's, 400's, 421, 428's. True the large main blocks arent as strong as the small main blocks but keeping rpm down and hp under 1000 can help it live a comfortable life.

Marks(LPI) suggestions were excellent Im sure he could guide you thru making good use of what you have for a block. Personally I'd put a 421/428 crank in your 455 block(makes it a 434 or 440) and build from there.

[carbking]

Like I said in my first post, no offense meant to anyone.

And I personally like turbos; I still have a factory-turboed car I special-ordered in 1979! And have had others.

It was just the level of horsepower I was questioning. For those who are capable of handling this level of power, with a car with the additional modifications; have fun, and be careful!

Jon.