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Old 06-18-2023, 10:31 PM
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PhenyxC3
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Default Engine build question

I’m looking to build a stroker for my 78MY C3. I’ve built several engines in the past, but all were gen 3. I’m NOT going the LS route with this one. My goal is post 87 roller cam setup. Something I can drop in without much fabrication. Any recommendations on a short block to start my build? Anything I should avoid like the plague? Planning on an aggressive setup which will be used with a Vortech. Appreciate any help, this is my first non-fuel injected build.
Old 06-18-2023, 10:51 PM
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calwldlife
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St. Jude Donor '22

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block is your issue.
needs clearance for stroke crank and piston rods mounted to crank.
there are high end blocks already clearanced.

nice
Old 06-18-2023, 11:18 PM
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PhenyxC3
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The bottom end would be assembled by my machine shop. But if too much material would need to be removed, may be better off keeping it a 355. Don’t want to compromise the integrity of the block. Hmmm
Old 06-18-2023, 11:21 PM
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Originally Posted by PhenyxC3
The bottom end would be assembled by my machine shop. But if too much material would need to be removed, may be better off keeping it a 355. Don’t want to compromise the integrity of the block. Hmmm
done all the time.
takes skill, proper parts.
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Old 06-19-2023, 07:56 AM
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augiedoggy
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There is not a whole lot of clearencing required and the amount does depend on the actual components used.
Old 06-19-2023, 08:13 AM
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Stormin_Normin
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87-92 were the roller blocks with one piece rear main. Some were drilled for lifter guide plates, some have machining for manual fuel pump, and threads for roller cam retaining plate. I think any will work, but the above provisions with a 4 bolt block would be the best. Now finding one is getting harder, summit used to sell 2 bolt they converted to 4 bolt blocks.

Old 06-19-2023, 08:33 AM
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Jebbysan
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I just built a 385ci small block with a standard basecircle hydraulic roller cam using an Eagle rotating assembly with Mahle pistons....6.0" rod. I mocked up all 8 pistons on the rotating assembly and not one thing hit anywhere and the rods cleared by a mile......this was a circa 1990 roller block with a stock 1987 C4 Corvette pan (which is a great pan for these builds in a Vette....exactly like the old "long" sump Vette pan but for one piece seal...sadly, no one repops it....we found ours on E-Bay...for $75).....Eagle and Scat finally figured out how to build a strong rod that clears everything.....and it was 100% the rod the reason for stroke clearance......400 Chevrolets were not stroke clearance from the factory with stock rods ....sooooooooo.......
This engine used a 180 Dart Pro-1 head that I spec'd (and that I spent about 4 hours on the bowl area on-just a touch up) and a healthy Howards hyd. roller cam with a Performer EPS intake that I cut down the center divider a bit.......it is 10.4 to 1 compression with a 750 Street HP Holley vac sec....
The customer is a member of this forum.....it is in an 80' Vette . He claims he had to learn how to drive the car again because it spins the tire anywhere in the rev range from 2000-5000....and shifts out clean at 5600 rpm.....I estimate it makes 450hp and about 500ft/lbs. torque........
The customer/forum member let me experiment on him about my large carb/large cam/small head theory.......and it is a resounding success.......

There is really nothing in the 350ci arena that you should stay away from......some say the one piece blocks are weaker but I have never confirmed this to be true and GM builds crate circle track engines on them to this day. Late model Vortec style blocks have no mechanical fuel pump provision......and no bypass for the water pump so this needs to be plugged at the pump bypass hole......

Always build as much compression as possible into the build.....small blocks will go 10.5 to 1 on pump gas no problem with fast burn chamber (which most modern aftermarket heads have).......you can run a larger cam with high compression, they are easy to tune and sound terrific......
Low lift flow and high velocity is the name of the game on the street......small ports with high CFM rating will make Kansas flat torque curves and plenty of horsepower......there is really no need to build an engine that revs over 5800rpm unless you want it or you are class racing.......
I always try to encourage folks to make the jump to a 406 if they can....but this isn't always in the cards as some have blocks already that they want to use....400 blocks are drying up.....but if you have the money for a Dart block, do it.....the 406 will make a believer out of you and is my favorite SBC combo......IMHO, you will never need more on the street than a 406 can provide.....and the no stroke clearance deal works here too......
Lastly, the biggest thing to look out for are not the parts....but the guy who specs them......you can lose a LOT of value by having some pretentious bonehead spec parts for your build (there are a LOT of these people out there still).......then you are stuck making **** work that spent a small fortune on for substandard results.



Jebby
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Old 06-19-2023, 11:50 AM
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Thank you very much! Definitely going to look into 400 blocks as well. This is the type of information I was looking for. It there a lot to converting a 400 to roller cam? Obv would need a button and reinforced timing cover.

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Old 06-19-2023, 11:57 AM
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60 SHARK
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Originally Posted by Jebbysan
I just built a 385ci small .....I always try to encourage folks to make the jump to a 406 if they can....Jebby
,
I just peeked in on this thread.. Great info Jebby, thanks for your time and thoughts. I would love your help on building a street engine one day,,,,,
Old 06-19-2023, 11:43 PM
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If your going to do boost dont waste anytime on a production block go strait to at least a dart SHP block.
Old 06-21-2023, 11:10 AM
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Originally Posted by Jebbysan
I just built a 385ci small block with a standard basecircle hydraulic roller cam using an Eagle rotating assembly with Mahle pistons....6.0" rod. I mocked up all 8 pistons on the rotating assembly and not one thing hit anywhere and the rods cleared by a mile......this was a circa 1990 roller block with a stock 1987 C4 Corvette pan (which is a great pan for these builds in a Vette....exactly like the old "long" sump Vette pan but for one piece seal...sadly, no one repops it....we found ours on E-Bay...for $75).....Eagle and Scat finally figured out how to build a strong rod that clears everything.....and it was 100% the rod the reason for stroke clearance......400 Chevrolets were not stroke clearance from the factory with stock rods ....sooooooooo.......
This engine used a 180 Dart Pro-1 head that I spec'd (and that I spent about 4 hours on the bowl area on-just a touch up) and a healthy Howards hyd. roller cam with a Performer EPS intake that I cut down the center divider a bit.......it is 10.4 to 1 compression with a 750 Street HP Holley vac sec....
The customer is a member of this forum.....it is in an 80' Vette . He claims he had to learn how to drive the car again because it spins the tire anywhere in the rev range from 2000-5000....and shifts out clean at 5600 rpm.....I estimate it makes 450hp and about 500ft/lbs. torque........
The customer/forum member let me experiment on him about my large carb/large cam/small head theory.......and it is a resounding success.......

There is really nothing in the 350ci arena that you should stay away from......some say the one piece blocks are weaker but I have never confirmed this to be true and GM builds crate circle track engines on them to this day. Late model Vortec style blocks have no mechanical fuel pump provision......and no bypass for the water pump so this needs to be plugged at the pump bypass hole......

Always build as much compression as possible into the build.....small blocks will go 10.5 to 1 on pump gas no problem with fast burn chamber (which most modern aftermarket heads have).......you can run a larger cam with high compression, they are easy to tune and sound terrific......
Low lift flow and high velocity is the name of the game on the street......small ports with high CFM rating will make Kansas flat torque curves and plenty of horsepower......there is really no need to build an engine that revs over 5800rpm unless you want it or you are class racing.......
I always try to encourage folks to make the jump to a 406 if they can....but this isn't always in the cards as some have blocks already that they want to use....400 blocks are drying up.....but if you have the money for a Dart block, do it.....the 406 will make a believer out of you and is my favorite SBC combo......IMHO, you will never need more on the street than a 406 can provide.....and the no stroke clearance deal works here too......
Lastly, the biggest thing to look out for are not the parts....but the guy who specs them......you can lose a LOT of value by having some pretentious bonehead spec parts for your build (there are a LOT of these people out there still).......then you are stuck making **** work that spent a small fortune on for substandard results.



Jebby

THANKS JEBBY
FOR AN INCREDIBLE BUILD!
I"M LOVING IT!

Old 06-21-2023, 11:19 AM
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Jebbysan
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Originally Posted by Street Rat
THANKS JEBBY
FOR AN INCREDIBLE BUILD!
I"M LOVING IT!
So glad you like it.....can't wait to ride in it

Jebby

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