Hey all, one more question about the 67 Camaro I'm picking up in a few weeks. If funds permit, I want to change the engine ASAP, staying with a small block for handling purposes.

I've seen many of the crate engine builders selling small blocks with 454 ci displacement.

Makes you wonder if you're really pushing the limits of a small block.

Anyone have any experience with one of these?

General thoughts?

 

I bought a SBC 427 because I can hone the block 2 times if that is need.
I was told by company that did build my 427, "don't buy a SBC 454, it is pushed to the limits"

 

I have the 434 ci motown block. Which is 4,155 x 4 inch stroke. I spent a couple thousand dollars on the calles pendulum cut 44 pound crank shaft. For the same price I could have bought the 4.125 stroke crank for 447 ci small block

The next over bore makes a 454

The motown is a standard deck height block. 454 is doable but the smarter option is the Dart taller deck raise cam block where you have rod and cam clearance and get away from small base circle cams the other thing is where the piston pin is in relation to the rings with 6 rods the taller deck is much better

 

Thanks for your replies. I think I'll stick with the 406 or 427.

Ideally, I'd LOVE to get an aluminum LS7 long block. I love my LS7 that I have in my Z06, especially with the cam I have in it.

 

Nailed it. However this build would be very expensive. Going with a lsx 454 would be far more economical imop.

 

A buddy of mine put together a 454 sbc and has it in an 86 Monte SS.

If I recall correctly, it has a set of Brodix Dragon Slayer heads, and a solid roller. i think it made a something like 610-620 at the crank.

Maiden voyage at the track resulted in a transmission failure, and the car still ran something like 11.17.

 

I will be doing an engine for my 85, the more I researched and spoke to engine builders - the response is that if you want to drive the car regularly and not keep replacing parts the 409 is the best bet. The stroke and valve lift are great in the 434+ and cause rapid parts wear which is ok at the track / not so much on the street.

I have a 383 and drove it a lot with no issues. 6+ years.

I'm looking at a 409 SBC for the replacement in the 85. The local engine builders all think this the a great street size.

Each size has + and - , I drive a lot so that is my deciding factor. Although I keep looking at the 572 .. it won't fit dang...

 

The best cheaper build is the 415 ci. Using a Dart SHP 400 block and then buy a 3.875 stroker rotating kit with 6 inch rods


never do a build with a stock 400 block

 

Do not exceed what the GM put in a std configuration SBC. If you want a good 550 to 600HP engine build the following:

AFR 210 Heads
Hyd Roller/Morel lifters
Dart SHP Block with 4.155 x 3.75 x 5.7" rod
EFI system or an 850 Carb with Airgap intake
10.5 to 1 compression
This combo will net you 550-600HP and 525-575#/ft

 

Years ago I built a 4.155 X 3.875 X 6 inch rod 421 CI for a friend. It has been a wonderful motor in his 65 Nova. I was wondering why you you would not exceed the 3.750 stroke? It seems to me that the additional 15 cubic inches is just extra TQ.


He had Edelbrock Small Block Chevy Victor Jr. Race Series Cylinder Heads. Not my first choice, but they seem to work with his port matched and bench flowed VJ single plane. It has epoxied in flow turtles and a 1 inch 4 hole phenolic spacer, AED HO-Series Carburetor 750HO-A running E85 fuel, and 11.2 C/R. For drag race days he unhooks the full length 3 inch exhaust and installs 14 inch header collector extensions to his 1 7/8 headers. I think the car is near 2800 pounds

 

I believe the big inch (427-440) SBC cat has been out of the bag long enough to be considered a very reliable high performance engine.

 

I the standard bore spacing....no matter what block you use....the 454 will have just .150 between the bores.......
I worked at World for a spell right when these were released......
Mitchell Jr. told me to my face that absolutely NO nitrous what so ever on this engine.
Build a 421.......or if not running nitrous....a 434.

Jebby

 

That was the very reason I opted for a 427 vs. a 454......that .150 bore spacing was just too small for me......even though a special head gasket was made for it, I always wondered how long it would stay sealed.

However, if you want one, they're available........any experience with one of these ?.....https://www.summitracing.com/parts/m...0ctc/overview/

 

The GM engineers never designed the lower crankcase area for anything more than 3.75" stroke. The hotrodder gets led down this path of MOre is Better and his wallet is emptied on CID. The problem is to make that CID run it takes a very good good oil pan and large headers. We don't blink an eye putting on a 2" header on a 427BBC so we shouldnt' blink an eye putting a 2" header on a 434 CID SB. Inches are inches and the SBC is Bigger even though the other engine has Big in its title.

 

Depends on your definition of reliable. If its built, put in the car and see's 200 miles a year then yes. If its built and sees 2500-5000 miles a year no. The engines need expensive add on's to make them reliable.

I see more lower end failures in morphed SBC with large stroke than any other engine segment. These engines don't need $150 oil pans. They need extensive thought put into the oiling system.

 

I was never talking about stock blocks!!!!!!!!!!!! I only talked about Motown and Dart. I'm not even a Dart SHP block fan, I prefer the raised cam tall decks. I also only install 7&8 quart pans made for these not stock blocks.

I specifically stated that I would never recommend a 400 block for any build.

Oh for the record I put about 10K miles a year on my 434 and yes it does have a 4 quart Accusump. I use a high volume pump without a bypass and use the oil weight to adjust my pressure to not exceed about 70 psi hot. The tiny piston rings seem to go in under 20K miles. This last motor got the total seal gapless rings and I'm going to see how many miles they last. I also turned down my rev limiter to 7000. I don't really feel choked with my 1 7/8 headers. I should have just bought spread port heads years ago and gone with custom headers.

 

Raised cam location blocks are expensive builds. Nothing cheap about those builds and special parts they require. Most on here are not going to that expense.

If your loosing rings that soon then the side loading is present due to the stroke. The GM LS has had a thing ring pack for years, that's how we found out about ring flutter and opening up the second ring. The LS platform will run 100s of thousands of miles with thin rings.

Do you have any testing with the headers on the engine at that rpm to show a loss, no loss, or a gain? In my experience with customers we have seen gains with larger headers on these engines on the dyno and at the track.

 

I'm thinking of building something similar, do you have a tq/hp graph, curious about low end and how flat the tq is.

 

Below are 2 sheets. One is a 406 with 210 Profilers. The other is a 406 with older AFR190's. Both have very mild camshaft profiles in the 230 range. With a camshaft in the 240 range the power would be there.

 

I have built quite a few big inch small blocks and there are a few things to consider:

1) At 4.00 stroke and a 6.00 rod the piston has a 1.00 C/D which puts the ring pack high in the piston and makes a short skirt......this may mean nothing to you but you cannot run much more than a 200 shot of nitrous on it as the rings get too hot......
A 3.875 stroke moves the ring pack down .060....just enough.

2) A 434 WILL require a .900 base circle cam unless you murder the rods to clear......this is assuming you run a roller that has enough lobe to make it run the way it should.......
Small lobes are hard on parts and the loss of core size sets the cam up for a lot of torsional twist at high RPM.

3) You need a LOT of head to feed it.......I would run 227 CNC Pro 1's on these but they could have used more.......

4) A 2" header is mandatory at 600+ horsepower to not choke it.....which means header plates and custom headers.

I built nitrous 421's in Michigan that made 1000+ horsepower on the hose......but Shaft Rockers and belt drive timing were the order of the day for valve train stability. (READ LONGITIVITY).

This is why my own car has a 406 in it......simple simon!

434's run great but not for all out racing on a 9.020 deck block.

Jebby