You're totally right, I have 400hp in my current 355, and I don't need any more than that. My vette is a dd and rarely sees anything over 3800rpm (well,once in awhile). So, why am I currently building a 383...? Simple, because I can. And although I don't need more power, I want it, it's like a drug. It's not easy to find 400 blocks around here, but I can buy standard bore early 350 blocks all day for a hundred bucks. My current rotating assy has seen several blocks. Again, 400 blocks are harder to come by if you need to swap one out.

 

better than 200hp in traffic..........Although, I live on the edge of a small(er) town......1 block away is a nice curvy road through the heart of the Willamette Valley (Mission state park).......When I drive the road I usually see about 5000 rpm on the tach---55mph road and 25 mph S curves----which is why a solid axle rear is a waste of money ......Yeah i'll take my 383 stroker any day

 

Don...you will end up falling off a mountain doing that crap



Dep

 

Because the 355 scares the crap out of you???? No need to be embarassed. Admit it


Dep

 

I didn't say I WAS GOING OVER 55 besides it is in a valley----no moutains---only trees and telephone poles on corners.

Don

 

 

I was talking about the 400 small block. With a clean up bore they are about 406 cubic inches, use the same heads and everything else. As for cooling they ran fine in vans in tough locations. I know a friend who has a small block 406 and he loves it.
Given I was building a small block I would start with the 400 block and work from there to gain maximum cubic inches as easy as possible.

 

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Number One answer on the board, darlin' !!!!! "[/I][/SIZE][/COLOR]
[/Richard Dawson][/B][/FONT][/COLOR]

Thank you Richard. I er... learned that the hard way with my 283 fuelie, now I have a plaque on my garage wall made up of pieces of camshaft, pistons and connecting rods and chunks of my original matching numbers block with the caption " Do not exceed 6500 RPM EVER!" 5500 is just plenty for the stroker in my '75. Much cheaper...

 

That's what weekends and lightly trafficked roads are for... and 400RWHP is good for revving at the grandma going 10 under in the fastlane

The LT-1 and other 350 and lower "classic" motors you speak of are race-bred engines and as such are not the best choice for the street, hence the advantage of bigger engines/less RPM. Me and you obviously use our engines in different ways, so don't get me wrong. If I was racing in vintage-style and in a straight line I'd be using one too.

But... what is this "enough" you speak of

 

I won't preach (even though it is Sunday). But please allow for the "Murphy factor" when screwing around on the street. Those "lightly trafficked" roads always have some nitwit woman with a cellphone jammed in her ear that pop up out of nowhere. On the strip you don't have to worry about that. When you get older and wiser you'll understand
Besides, there's nothing on any consequence to race on the street anyways

Dep

 

I don't feel that rpm is important for a street machine and 99% of us have street machines. Some like to race them but again they are street machines taken to the track.
Building rpm into a motor is alot more expensive then just building a big low rpm torker.
I run with a friend, he has a 355 with 3.55 gearing and a 350 automatic. When he is buzzing along at 4000 I am only turning in the 2 or low 2 range. Which motor will wear out first? Which is getting the better gas mileage? Running cooler? Less noise?
I was looking in the summit catalogue last night and they only rate their 383's at 340 horse??? Don't recommend over 5000rpm? I know they don't want warranty problems.
Building rpm into a motor costs big dollars. Use those dollars to build a bigger cubic inch motor and have a much better faster street motor.There are no class rules on the street and cubic inch wins.
Guys I have been there with the high winding motor, wild cams, steep gearing, high stalls where I would do anything to pick up another tenth.
It isn't worth it. Build big, something that runs on regular fuel, idles great in traffic, doesn't overheat and no steep gearing and definitely overdrive and enjoy the car.

 

True. "There ain't no replacement for displacement" and "RPM is a poor substitute when the rules allow larger cubic inches".

The only reason to RPM an engine higher is to increase the power output of what you actualy have under the hood NOW. If a bigger engine is feasable, you will make more power with better relaibillity using a bigger engine (all else being equal).

Bottom line - we are converting fuel and air into work. The more fuel/air we can convert during a drag race, the more work will get done in less time. Bigger engines can convert more air/fuel than smaller engines for any given amount of time at the same RPM. More RPM's on a smaller engine will also convert more air/fuel into work to try to even the score BUT they also stress the limitations of the hardware more, so relaibillity is reduced and parts break.

The 383 is an inexpensive way to give the C3 exactly what it needs. More cubes and more torque over the more frequented RPM band without the cost and hassles of swapping to a big block. I would not yank a '70 LT-1 to stroke it but if I had, say a stock later 70's model I would give it a lot of consideration especialy at rebuild time. I would have done it myself but the bottom end was still in too good of condition to toss it.

-Mark.

 

Mark is right on. I was so convinced by the effectiveness of my 383 conversion, that when it came time to rebuild (actually replace..)my fuelie 283 which had died of high RPM,I spent about $400 to clearance the block and slipped in a 327 crank. The result on the dyno was nearly 40 ft/lbs of torque over stock at a lot lower RPM. That had a dramatic effect on drivability too. No more peaky performance in traffic, just good pull from 1200 RPM and up. That engine, will fuel injection and solid lifters would pull 7 grand, but it won't ever and doesn't have to now. (To expensive to replace anyway).

Now, I would never build a 350 for the street. Even for a budget rebuild I'd use a stock cast 400 crank because it makes such a difference for so little money. Just keep it under 5500 RPM.

Think about it. How many of you would spend $400 to get 40 more pounds of torque in a reliable engine that looked dead stock? What a bargian.

for the street: Stroke everything!

 

Norval have you priced building a decent BB from scratch these days??? Whew... Pricey is the word. Not to mention all the other things that go along with it to swap over from a SB to a BB in a vette. And in My case and maybe as far back as 80 models it won't fit without cutting stuff. There's just not enough room for the back left side of the motor.

When you weigh out the total cost of the swap, the 383 beats it hands down.

Converting a 350 to a mild 383 is cheap these days, actually all you need is a 30 over bore on the block, crank, flywheel, balancer and pistons. Everything else can be reused... and with the torque they make... it gives people the big block feel at a small block price.

I'm with Glen on the 406... Although I know a lot of people with them with no problems...I'm just not too crazy about the siamesed cylinders and short rod.

 

"Kick-save..... and a beauty!!!!!"

 

Thanks Glen...My bad

 

No I haven't priced building a bigblock from scratch. I built mine about 14 or 15 years ago starting with a LS6. Over the years I have refreshed it and invested about $10,000 more with the blower.
If I was starting today I would find a wrecker 454 and rebuild it. Actually that is not true. I would buy a specialty block, stroker crank and build about 570 or bigger but if money was an issue I would go the 454 wrecker route.
As for converting, I did that and I used EVERYTHING from the donor motor, long water pump , all brackets, small block ignition, same transmission, same motor mounts and even the small block rad. I am now running the short waterpump but for years I ran the long water pump and stock rad. Even the stock small block springs work fine.
I am hopefully going to help a friend upgrade his 350 and I am leaning towards a 406 small block instead of the stroker 383.
I wouldn't even bother with a 454 anymore and at the least go to 496 as the smallest.
The 502's are hard to beat.

 

Somewhere a while ago I read an article of rod ratio's and a very well know engine builder did a number of tests on different ratio's and found it made absolutely no difference in power.
The factory found the ratio acceptable for production use. Most of use never wear out a motor in our vets from high mileage. Agian cubic inch is all that matters and if I can gain 23 more from just a cleaned up 400 and most find such a difference in gaining 33 cubes with a stroker why not go for it????

 

I don't think most racers use the 5.700"-rod for more-power, but for better rod-angularity (? )at 90* from TDC/BDC, causing less wear-and-tear.

 

Well I see a LOT of weird stuff being shovelled out here. Let's see if I can sort through the

Norval says: "There are no class rules on the street and cubic inch wins."

To say that statement makes me feel "uneasy" is putting it mildly.
Cubic inch wins???? Wins what??? A quicker trip to the gas pumps is all cubic inch wins on the street. What EXACTLY do you MEAN by "wins" anyway??? I hope it's not what I'm thinking it means.

stingr says: "There ain't no replacement for displacement" and "RPM is a poor substitute when the rules allow larger cubic inches".

Not exactly an original thought or something somebody just thought up
But what RULES are we talking about. There ARE no "rules" for the "street". And at the strip, big blocks are regularly shot down by a well built small block. So that quote may have to be retired.

Norval says: "Building rpm into a motor is a lot more expensive then just building a big low rpm torker."

Yes...you CAN install a big inch truck motor for cheap (like the one that came in my year Vette)...454, 470 pounds of truck tork, zilch worth of horsepower(270). It may look impressive residing in that engine compartment, but it WILL get dusted if it races a teeny tiny 4.6 Mustang. Which, BTW, has much LESS tork (320 ft lbs) than the moose of an engine I yanked out. Save the tork talk for the truck forum. I don't yank down trees with my car. I don't haul horse trailers. I don't pull a Chris Craft boat.

Why convert a 350 to a MILD 383 when you can take the stock bore engine and restore it to a HOT 350/370 HP engine? Of course, if you ARE hauling boats and trailers around, that probably wouldn't be a good idea

Dep