454 Small Blocks pros & cons ... your comments appreciated

[studiog]

http://superchevy.com/tech/0407sc_mouse/

http://www.jegs.com/webapp/wcs/stor...01&categoryId=26273&searchItemId=86179&CT=999

http://www.jegs.com/webapp/wcs/stor...goryId=28673&parentCategoryId=10763&langId=-1

 

[Mark Stahl]

I own one of these motors. It is a Bill Mitchell motor. I have the 415 version.. The motor came with proof that it was putting out 522 hp. There was no doubt about it. The problem is that the thing was so over carbed and so over cammed that these were the first things I changed. The next problem is you cannot run your tach with the distributor that comes with the motor, since it does not have a mechanical tach drive. Which means unless you convert your tach to an electronic version you're screwed, or buy a different distributor. Since doing all this the motor is excellent, but if I had to do it again I would not. One more lesson learned. If you do a search on my posts I have a half way decent shot of the motor installed. Look for at great mechanic found. Mark.

 

[67l36driver]

Why not just start with a real 454? :L Use the standard L36 cam for gobs of torque and good drivability.

 

[jldecke]

Just remember there's no replacement for displacement.

 

[IH2LOSE]

I think you have to decide your ultimate goal.

track time or driveability

For me driveability is the most important,having vacum for my power brakes,run on standard pump gas.Maintnence free motor

from there if this motor fits the bill go for it.

 

[studiog]

I should have exlained my application for the motor. I AM ONLY SPECULATING right now but I am thinking of a resto-mod C1. I would prefer a small block with big cubes just because it would be easier (for me) to work with an engine with the same foot print as the original... less on the fly engineering which should equal a quicker completion time and more room for options like AC/PS/PB etc. (Don't get me wrong, I love the big blocks, I had a 454 in my 74 Coupe, think it was the last year of the big blocks in Vettes. I would be looking for driveabiity and not an overly lumpy idle.
Thanks to all for the input so far, it has been very helpful.

 

[studiog]

I own one of these motors. It is a Bill Mitchell motor. I have the 415 version.. The motor came with proof that it was putting out 522 hp. There was no doubt about it. The problem is that the thing was so over carbed and so over cammed that these were the first things I changed. The next problem is you cannot run your tach with the distributor that comes with the motor, since it does not have a mechanical tach drive. Which means unless you convert your tach to an electronic version you're screwed, or buy a different distributor. Since doing all this the motor is excellent, but if I had to do it again I would not. One more lesson learned. If you do a search on my posts I have a half way decent shot of the motor installed. Look for at great mechanic found. Mark.

Looks great Mark. Hope you don't mind I grabbed your pic and posted it here.

 

[Stan's Customs]

I too have been considering a big block. The installation doesn't seem like that big a deal if I haven't overlooked anything. Steering shaft clearances and carb height being the biggest factors...A pain for sure but like any other project...there are issues when upgrading a smallblock too..

We go to so much trouble to make these cars drive and handle right ...my unknown area is what (if any) problems arise with the extra weight up front...(C1 application correct?) I'd like to know if that is significant issue from those who have been there..

The big big blocks of any kind are so much stronger and idle friendly (for a/c etc.)...sooo I really perfer big blocks anytime it is feasible on a custom project..

 

[IH2LOSE]

I too have been considering a big block. The installation doesn't seem like that big a deal if I haven't overlooked anything. Steering shaft clearances and carb height being the biggest factors...A pain for sure but like any other project...there are issues when upgrading a smallblock too..

We go to so much trouble to make these cars drive and handle right ...my unknown area is what (if any) problems arise with the extra weight up front...(C1 application correct?) I'd like to know if that is significant issue from those who have been there..

The big big blocks of any kind are so much stronger and idle friendly (for a/c etc.)...sooo I really perfer big blocks anytime it is feasible on a custom project..

Stan I will look into my notes at home for my cars weight ratios. At this time I am nose heavey,( I think as it sits I have a 53% biase towards the front.)
I found this out by having the car 4 coner weight by a circle track racer. This may explain why i am having such a traction problem with the car. I still have to complete the installation of stereo systems amplifier and trunck mounted subs,and then the trunck carpet and leather covers. Know i regret not paying the addtional moneys for an aluminum headed crate motor but it seamed ssuch a miniscule weight savings I passed on it.

The good news is that when the trunk is complete I should have a neutrally balance car with out having to go to the aluminum heads

 

[Mark Stahl]

I don't mind at all. I was not sure how to pull it up. I just took the 64 out for a nice long ride. It was hard to put it away again. Mark.

 

[Stan's Customs]

That does look good Mark...Doesn't look like you have any hood clearance issues in that pic...Do you?

Thanks IH2 ...I am curious about that. Weight transfer on short wheel base cars is tough...especially when they are nose heavy and have limited wheel well clearance...

 

[Kid_Again]

I think the big disadvantage of a big cube sb is the price. Plus, you have to keep the revs up.

I had no clearance problems with a zz454 in a '66. With the stock medium rise manifold and a drop-base air cleaner, it JUST clears the hood. Side pipe headers JUST clear also.

 

[Stan's Customs]

Big blocks were stock in some mid years..so they are much easier than the C1's...no clearance issues there at all...albeit close.

Cost is really out of line on small block big inch motors....why not just use a big block to begin with, they will run harder than the "big" small blocks...provided they are similar performance wise.. The issue used to be that small blocks were cheaper...that got lost in the fracus...Big blocks can be built very economically comparatively ...they are tough too.

If you have a small block fine ...if you are starting from scratch...put a pencil to cost and horsepower/torque. No brainer.....and hi-po small blocks get poor mileage so even that is not as much a factor as might be imagined. Like anyone that can afford one of these cars..can't afford fuel in the first place.

 

[Mark Stahl]

If you look at the pictures of my car (under my old posts) you see that she has a 67 stinger hood. This motor had a tuff time at idle do to the cam and carb that comes with it. YES it does not make the power until the higher rpms (I very rarely get up there to take full advantage of the power. IMHO a Gm crate motor would of been a better choice due to the changes that were made to get this motor to behave better on the street. The reason I picked this motor was my old motor was starting to lay down. It is all HP the way they advertise it, but as far as streetable well I guess everyone has a different opinion. When I called and talked to the builders direct I told them exactly what I would be doing with the motor. Long drives, stop and go traffic etc. They told me not a concern. I even ordered the smaller 415 version. The motor still rips with the changes made, and has been very reliable. However without the cam and carb change, it would be a nightmare. The carb is now a 750 with vac secondaries and even has an electric choke. The cam is now a comp cam 218/224 462/469 . Mark.

 

[Stan's Customs]

Are you talking about a small or big block GM crate motor Mark? Being a better choice that is...

 

[Mark Stahl]

Honestly I would go with a small block. Something that made good low end torque.The lesson I learned the hard way was you drive most of the time in the lower rpm's. That is where you really want the power to come in. This is only my personal opinion. I believe my 64 would have a tuff time fitting a Big block. Plus the added weight issue. A nice LS6 would be real cool but a ton of work. What is everyone elses opinion. Mark.

 

[grumpyvette]

just some info youll need to make an informed choice

a big block chevy CAN be assembled from readily available parts that weights close to or even less than a small block using expensive options like an aluminum block and heads,intake,water pump, etc.......but lets look at the more comon style combo with an IRON block and aluminum heads, intake, water pump. youll be about 80lbs-90lbs heavier than an iron small block combo, but what do you gain for that extra weight?
first you gain much better flowing heads,larger stronger rotateing assembly and potentially at least a larger displacement, and better engine cooling, a wider head gasket seal area between the cylinders, and generally significantly more hp at the rear wheels if both engines are built to a similar hp per cubic inch level of power.
lets look at that!
lets assume your sbc corvette weights 3500 lbs and has a 383 stroker based on the comon 350 block, producing 470hp
a similar big block stroker would be a 496, this gives you a 113 more cubic inches, if both engines make about the same 1.23 hp per cubic inch that small block makes the big block will make about 608hp but the car would weight aproximately 120 lbs more, yet the small block with 470hp is pushing 7.44 lbs for each hp, the big block combo even thought its 120 lbs heavier(engine plus accessories) has only 5.95 lbs per pound to accellerate...........approximately a 20% advantage, now both engines can be made larger, or more powerfull but the ratio and potential advantages only get slanted even more in the bbc favor

info/examples

http://airflowresearch.com/articles/article69/A-P1.jpg

http://airflowresearch.com/articles/article73/A-P1.jpg

http://airflowresearch.com/articles/article71/A-P1.jpg

http://airflowresearch.com/articles/article76/A-P1.jpg

http://airflowresearch.com/articles/article52/A-P1.jpg

 

[Mark Stahl]

Great info! If I had gone with a BB motor would my 64 been able to swallow this? What mods would be needed if you are trying to fit a BB in a non original BB car? Mark.

 

[BarryK]

Mark
I know that in '65 they somewhat modified the front of the frame in anticipation of the 396BB motors. I'm not sure if the new indent in the frame was to clear the motor or the different radiator but I believe that when trying to drop a BB into a '64 you may have to make a modification to your frame to allow for it.
others with much better knowledge than me ought to be able to chime in and help clarify this.

 

[Kid_Again]

Nope, sorry, the bb's fit '65 and up. You could fab a bb into a '63 or '64 but it requires reworking the frame.