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334 stroker engine

 
purplerambler69
I love my Chevy Chevette!
Posts: 2
Joined: 01/13
Posted: 01/19/13 07:39 PM

I was just wondering if anyone has built one of these engines or has any experience with them.  yes, i understand it is cheaper and easier to simply build/buy a 350.  However since reading what little i've found on them, im considering building one.  Heres my idea:  turning the 400 cranks main journals down to 2.45" and using a 6" h-beam rod.  this should give me a decent 1.6:1 rod ratio.  I see Keith Black makes a forged piston for this combo with a 1.133" comp. height.  I cant remember the weight of these, but they were pretty light, around 340g i think.  with the stock 9.025 deck height this should give me .017 piston to deck clearance, which i would probably have cut down with a deck shave.  For heads, im thinking 1.94" intake Vortecs due to the small bore.  Which should have me somewhere in the 10:1 compression ratio range.  I have most of these parts except for the pistons which are around $545, so most of the money will go to machine work. As far as cam specs, im up in the air on that.  From what ive read, small bore/long stroke engines seem to make their power at lower rpms,  however ive also read that circle track racers have used this combo.  where would this engine be more at home, on the drag strip or on the trail?  Or for that matter, it might make a good demo car engine... Any and all input would be appreciated.  Thank You!  

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pepsi1
I mow my lawn and find Chevys
Posts: 1718
Joined: 09/11
Posted: 01/19/13 08:38 PM

purplerambler69 welcome to CHP.

  I ran a 331 Pro-Stock Grumpy's combination for a very long time, in my "66 ChevyII.
  I didn't run the combo you have. But That little engine on a good Pass saw 9400RPM to 9600RPM at the big end. with 9.41ET @ 141MPH.. Bad pass 9.80ET @ 137MPH...

Now getting back to your engine. Need some information.

1.Your most intended use for the engine. Street/Strip street or strip.

2.Car or Truck it's going in.

3.Rear Gear Ratio

4.Automatic or manual trans

5.Tire Size (How Tall and how wide)

6.Carburetor Size

7.P/N of the Vortec Heads, Most Vortec Heads need work

8.Engine numbers off the R/Front pad

Long stroke engines mainly in circle track (to a point). The longer the rod the more torque the engine should make if the complete engine combination is correct. The Cam, heads, the exhaust, etc. Then at what RPM range should the engine operate in and be suffient. Remember its a pump.

Bob  

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tuffnuff
Moderator
Posts: 7841
Joined: 12/09
Posted: 01/19/13 08:46 PM

What block are you starting out with???

Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

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68scott385
I mow my lawn and find Chevys
Posts: 1994
Joined: 10/09
Posted: 01/20/13 12:18 AM

Are you talking about stroking a 305?  
68scott385 68scott385 68scott385

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tuffnuff
Moderator
Posts: 7841
Joined: 12/09
Posted: 01/20/13 12:50 AM

+1 Scott,
A 3.735" bore, unfortunately, doesn't allow for large valves.,. breathing ability will be the limiting factor of this combo.
At high R's, this thing will gag for air.

Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

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pepsi1
I mow my lawn and find Chevys
Posts: 1718
Joined: 09/11
Posted: 01/20/13 02:01 AM

Its so easy to build a 331. 4" bore block, and then you can stuff a 2.05"/1.65" valves in the head.(You can get a business card between the intake and exhaust valves. Thats how close they are. Thats why I asked about the Vortec heads they have limitations.
 Thats why the Chevy 302 ran so well.It had a 1.9 Rod Ratio, but you had to really spin that little engine...Smokey Yunick did it with 292 cubic inches...Until NASCAR caught him..... I believe the closer you get to a 2.0" Connecting Rod Ratio on a small block chevy is ideal...I know where you can get a Brand New Large Journal DZ complete engine, for $12,000. Thats complete.
  Purpleramber69 if that's what your shooting for you need to tell us what engine your using. Because the 400 block also needs some modifacations to be done to it.

Bob  

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purplerambler69
I love my Chevy Chevette!
Posts: 2
Joined: 01/13
Posted: 01/22/13 03:42 PM

Hey guys, sorry it to me so long to reply back.  The block i was going to start off with was a 305.  ive got a lot more of them than i do 350s.  What i was looking for was what you all thought of the small bore/ long stroke idea.  It sounds like it would make its best horsepower at higher RPM's, provided the heads and intake could support enough airflow.  If this is correct, it may be well suited to use on the dragstrip in say, maybe an S10 or similar lightweight vehicle.  of course the cam, transmission, and gearing would all need to work together with the engine.  

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68scott385
I mow my lawn and find Chevys
Posts: 1994
Joined: 10/09
Posted: 01/22/13 04:01 PM

If it was a good idea EVERYBODY would be doing it already. Small bore restricts breathing. Using forced induction just creates pressure (because it has nowhere to go) and heat (byproduct of pressure). Small bore long stroke engines have been tried by the factory and in many case have proven to be short of expectations. Why would you thing a long stroke would want high rpms? If you have to have a 33xCID motor, use a bored 350 block with a 3.25 stroke.

It's your money, spent it how you wish but starting with a small bore is like trying to drag race in reverse, at first it's easy but the more you push, the harder it is to accomplish.  
68scott385 68scott385 68scott385

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pepsi1
I mow my lawn and find Chevys
Posts: 1718
Joined: 09/11
Posted: 01/22/13 04:27 PM

A 305 Block will never take the punishment a 350 4" bore will take. Plus the available parts are almost endless.

1.350 Block with a 4" bore. Then punch it .030.

2.Use a 3.25" stroke crank from a Large Journal
327, or a large journal 307 crank has 3.25" srtoke
crank. These are not forged cranks. They are mostly
Cast Iron. If you look on a Crank throw and if it has
the letters NF. Thats a good crank to use. The NF means
it is Nodular Forged. You will only find them on the
older Large Journal Cranks from a 307 or 327.

3.That whole combination will give you a 331 Cubic Inch
Small Block engine. Remember you need to purchase pistons
for a 327 stroke with a  4" bore block. Then you can use
a large valve cylinder head. ie as large as 2.05"/1.64".

4.When your ready I'll give you some Crane Cam choices
so you can spin your 331 to the Stratisphere....

5.If you overbore the block .040 you will be at 333.1999
Cubic Inches Give or take.

But really if I were you I wouldn't run a 305 block for any
Hi Performance engine combination....

Bob  

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pepsi1
I mow my lawn and find Chevys
Posts: 1718
Joined: 09/11
Posted: 01/22/13 05:09 PM

1.4" Bore engine blocks to use.
P/N 3970010 check for 2 or 4 bolt. Look for .010/.020 under the timing chain cover. Or some blocks will have the 3 digits of the casting number also cast into the block by the dip-stick. look for 010

2.For your Large Journal stock crank for a 307 or 327 3.25" stroke cranks. The NF is cast into throw of the crank. Those are good cranks to use have them checked for cracks, and any scratches. They can handle 450 to 500 Horse Power.

307/327 Cast Cranks with 3.25" stroke. P/N 3911001 or P/N 3911011

327 Forged Cranks with a 3.25" stroke. P/N 3914672 If you can find one.

3.Cylinder heads and many aftermarket Aluminum with different intake runner volume. Valve sizes 1.94"/1.50 up to 2.05"/1.64". The 4" bore of the 350 block will execpt big vales.

4.Your cam selection will be one of the last things you choose.

Like I said I ran a 331 Small Block Grumpy's old Pro-Stock engine Combination, I did make changes and updated as I needed to.
That engine ran 9.4 @ 141MPH the slowest 9.8 @ 138MPH. It was spinning at the big end up near 9,600RPM. The car weighted 2600lbs

Bob  

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weels1886
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Posts: 11
Joined: 02/13
Posted: 03/09/13 10:03 PM

They're weaker blocks.
- TC  

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skyeking
I mow my lawn and find Chevys
Posts: 2738
Joined: 08/09
Posted: 03/10/13 04:11 PM

Hi there,
1886 is dead right. My 305 sonic tested @ 110/1000" on one side
of every cylinder after 30/1000"
clean up was assessed...Grab a 302 aand restroke it and you will get
more satisfaction for less money. A reworked 327 would be my greatest
option!!..  Good luck with the idea....Skyeking...  
skyeking

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