I have made the comment in another thread that I have some regrets about my 434 small block. A few people have asked for more info, well here it is....

Generally I tried to make a drag race engine for the street. I wanted to build a killer street engine and thought a drag race engine would be the way to go, it's not. I also suffered a case of 'as long as I'm spending this much...'

I have since learned that a drag race engine is not the same as a street engine. It has quite different design goals, longevity and low maintaince are not among them This engine would be a nice drag engine with a larger cam and a big, no make that two big bottles of Naaws :D
It would be a nice street engine with a different cam design, less overlap and better idle quality, it would be just as nice of a street engine without the expensive rods, custom pistons, forged stroker crank and splayed four bolt caps.
I shoulda built it myself as a 406, but since I built a 434 I decided to have a drag race engine builder build it and assemble it. He also recommended the carb and intake. He recommended a Holly 850 and a Edlebrock supervictor which are WAY too much for this engine, the 850 has been sold and replaced by a 750 ( add $150 ) and the Super is being replaced by a RPM Airgap ( add $200, less what I can get for the Supervictor ) I don't blame him, he's used to building 600+ hp engines that see drag race only use.

The extra stroke buys you almost nothing and requires custom pistons with a 9cc dish. The pistons are forged which sounds cool but are actually anoying, then again whith them rattling like that you know not to get on it till they quiet down. I will probably never run nitrous so forged pistons are stupid.
Coated Hyperutetic would be mucho better

The extra stroke makes it near impossible to get the compression below 10.5:1 hich on any pump gas around here is about a point too high. I wouldn't ever build another engine with more than 10:1 and would probably shoot for 9.5:1 so I could run 87 octane if I wanted...

My cam has a narrow Lobe seperation ( 108 ) and 139' duration. it stinks of half burned gas at idle and doesn't produce all that much power ( 460 hp ) You can make that on a 406 for a whole lot less.

What I did right...
Well I do get 460 hp and 503 ft lbs of torque :D
The Moroso 191 7 quart oil pan I like
The AFR 210 heads are good and still one of the few choices for big displacement smallblocks.

Now remember this. This was my first ( and probably only ) open pocket book engine, I like it and someday it will be perfect, well maybe...

 

Thanks for sharing your insight.
I can certainly see your point about going to BIG with the cam, carb, intake, and etc.
I would like to build an engine with a bullet proof rotating assembly like yours with a head, carb intake, piston (9.5:1), and cam package that would have a hard time challenging the rotating assemblies strength. It seems like that would make for a LONG lived street combo. 400 to 450 hp with 400+ lb/ft of torque should be easy enough to attain. Many years worth of GRINS! :D

 

Thanks a bunch for your insight on the subject. I am currently shopping for a 400 block for a buildup of my next motor, or shopping for a long stroke crank for my current 350 block. The local cost of machine work is driving me to a 400 buildup rather than machine my current block for the 383 kit and balance.
Like you I do not plan to do this sort of buildup again and would like to get it close to correct the first time.
Hope that you can resolve your issues soon.

 

Keith

It's easy to get carried away, I think we all do to a cetain extent. I think to biggest mistake made by people drive like cruiser is to build a drap engine. I think you see that know. I know I over cammed my 383 and am probaly going to put a smaller cam in when I rebuild it. With a little more work (and more $ :eek: ) you can tame your beast and have a great running and fun to drive 434. Can you go with thicker head gaskets to lower the compression?

1979toy

Ther is very little or no machining to run a 383 crank in a standard 350 block, one of the reasons they are so popular. Just make sure the rod bolts clear the cam.

 

This sounds like the post I should have written on my last engine project. I am guilty also of the same crime.

This TimeI thought I knew better and so I ordered a 385 fastburn from GM and I wonder now if it won't fall into the same catagory. I could have bought the 330 HP Crate for $1200 less.

Nawwwwwww I like the fastburn, Gotta have a little compromise though and I think it will work out just fine.

You are correct that a Drag Engine and a Street Engine are not the same. I raced drag cars for years and it is hard to break the old habit I learned the hard way that in a drag car bulletproof is better and that a sissy engine won't win any races. I have also seen many a good engine in an ill prepared chassis that wouldn't do anything because of the overkill of engine in a stock chassis.

We all live and learn. It's just that some of us have to pee on that electric fence to see for ourselves I guess........... JIM

 

:eek:
427V8 thanks for the info and when the time comes I will give that more thought when comming up with a nice engine combo/setup.

 

keith
cold air is a must. do u have it?
Have the valves been unshrouded?
That plus some work on the pistons will lower compression, if switching to a wide lobe sep. cam does not do the trick, i think it will. see gkull for some cam ideas.
I think a proper cam will amaze you! :yesnod:

 

Good post Keith, it'll help some of the folks out that don't have much experience with motors. Depending on the engine builder some ask very few questions on what your goal is when you contract them to build an motor for you. And are reluctant to try and talk a customer into building a "milder" motor even knowing it'll be more streetable.
Sorry to hear you gonna have to lay out some $$$$ to make your car more comfortable to drive. But you've got a great base to start with, a little less cam, intake and carb and you should have a real beast with a temperament for the street.
If you ever need an extra set of hands drop me note and I'll swing up there.

 

Since I've been on this forum I've been inspired with you & Monty with your big small blocks. I've been planning on building such a motor. I've been saving up for a tall deck Dart or Rocket block.
Do these motors have reliability issues? If so, I'll go with the 4.50" Merlin or Dart big block with a 3.76" 427 crank (the old Can-Am 478 motor of the late 60's)
The aftermarket blocks (small & big) would have the same price tag (expensive)
I was leaning toward the lighter small block but now you have me reconsidering.




[Modified by 71coupe, 8:53 AM 5/27/2002]

 

Me thinks I came across as to negative on my engine. It IS a nice engine, the bottom end is bullet proof :D the heads ROCK. With the new carb and intake I think things will be pretty :cool:

71 coupe
I don't think there are inhearent reliability issues with a 434 small block. It should be good for 1000hp or more which is fine by me!

Scott
I'll keep you in mind when I decide to do a cam swap :D
The main point I was trying to make is that I vastly overestimated what I needed and could have spent less to get the same output...
I alos got advice from a Race engine builder who builds great race engines, but I don't need a race engine...

One other thing to think about is why do you want a 434 small block??
90% or the people don't understand, 9% don't believe you abd 1% say 'really? Cool...I've been telling people it's a 400 smallblock, it's just a lot easier:rolleyes:

 

As you can see from my sig I have a very hot cam with a very narrow LSA. I am pleased with my motor and the car runs great. I would pick the same cam next time. The valves need lashing about every 2000 miles but they are only .001 to .003 off so it is really not needed even then.

I have over 9,000 miles on the motor and they have been very hard miles. Drag racing, auto-x and track days. I believe that people way over spend on the bottom end. My $1,000 bottom end has taken some serious abuse and it is still going strong. I will likely be freshing up my motor soon. 9000 hard miles a lot to ask. It is my opinion that you need bigger flowing heads. If you really want to wake up that motor get some Pro Action 14 degree heads. They flow 350 cfm out of the box.

My motor loves 93 octane pump gas. The fastburn heads have great combustion chambers but need some serious port work to make HP. I think I spent $1,750 on porting the heads and bigger valves. I have done numerous dyno pulls and the motor has never pinged no matter what I set the timing at. It likes 34 at 3400 rpm.

I have learned alot on this motor. But the basic package is good. In addition, this is the first motor that I have built and I did it in my garage. :D

 

Keith,

This is one of the reasons I went with the 355 instead of the 383, but to a much different degree.

I reasoned it back and forth. Then the reality set in. I drive my Vette less than 5000 miles a year, I never race it, and I don't give a crap about big numbers, the car will never see a dyno or a track. I like bragging points, it's nice to point in the hood and rattle off stats and parts. But it's not worth the dent in my checkbook.

And I want trouble free enjoyment.

So I stayed with simple but proven hardware.

Thanks for the candor. Here's to hoping it all comes together for you. It sounds like you laid out a lot of cash, and you deserve to enjoy it.

Good luck!

:cheers:

 

Keith I think that possibly because your cam is pretty mild considering all the cubes you have, then you have moderate heads but a big ol' intake and carb setup that maybe the combo just needs some finnessing! A chunky roller, a Victor Jr. maybe and a 750 cfm carb would probably restore some streetability and give you more power.

I still cannot get over Car Craft pulling 540 hp out of a moderate 383. AFR 195 Race Readys (the cheap ones), 292s (solid FLAT TAPPET cam), Victor Jr., Holley 750 HP (pricey carb), 10.5:1 I think. Your motor has a lot more cubes, better flowing heads, if you redid the cam/intake/carb I cannot imagine how you couldn't exceed that number pretty significantly!

That is what I'm hoping anyways, because your combo and my yet to be run motor are very similar!

later

Rob

 

It's great that Keith has a 427 SB. No other comments on his engine here!
There are several points Keith seems to be making about engines in general.

Overdoing it on the engine (for the owner). Generally one increases power a little at a time until they find where they want to be. There are many jokes that start w/ "You know you overdid it when..."
While more C.I. is better, cost effective may need to be considered as in deciding on a 406 or larger. NOTE 400 to 427 is not the same as 350 to 383!
Overdoing it on C/R gains little (maybe nothing) & the downside is detonation & no engine.
NOTE TRW spent a lot of money years ago to find out how to make forged pistons. They are very popular & many use w/o a rattle.

Again these are comments in general, not on his engine or him. It takes a big man to say he overdid it for what he wanted.
:cheers:

Some are surprised that a large high HP engine may have little low rpm power. The operating range may be moved up to 3000-7000 for example instead of idle to 5500. Have had people following me who complained min. speed was 45 (trying to keep engine running in & out w/ the clutch) & then min. cruise was 85 (w/ very low rear gears). No use in telling them WAS WAITING for them!

:cool:

 

I'm with Smith. I can't get my motor to ping on 91 octane. So my next motor with be something like 11.2 - 11.4 cr. and 420ish ci. I've put nearly 17,000 miles since last May when I put my solid roller motor in. I drove it to work today because it's so much fun. I've put on nearly 4000 miles and I keep thinking about pulling the valve covers and checking the lash. at first I was checking them every 500-1000 miles and they were always right on within a few thousands.

Somedays I'd like a hotter cam. Somedays I want a lesser cam and 3.90 rear gears. Now that you have learned something about motor designes. Maybe you can build a better mouse trap. I thought about it for months before I decided on my custom cam grind. Monty did it right. He had three custom cams made and ran each one on the dyno.

I don't like Edl Victor Jr's. Your engine builder wasn't very street wise. I use the Weiand team G tall single plane it's build for lower rpm.