A12 Dilemma....

[HawkRod]

Like others, I took my numbers matching engine and 4 speed and put them on a shelf. Pictured below is my 500 cubic inch engine, with added fuel injection, A/C, and other mods. But I tried to make the car look as stock as reasonably possible.

In reading through this thread, it seems to me that you want to keep the numbers matching engine in the car (I get it), and also keep it very stock looking.

I would suggest building a mild stroker engine with a roller cam. Why? This will still make great power, especially low end torque, which is what you feel when you drrive around to shows, etc. But, it can look totally stock and will easily run on pump gas we have available today. Yes, you will lose power by going through restrictive heads and exhaust manifolds, but I don't think your desire is maximum horsepower. Finally, a mild stroker will be very reliable and you will have very little chance (if built right) to damage your original number matching block. Plus, you can put your original reciprocating parts on the shelf if/ when you sell it.

Good luck whatever you choose!

 

[oldkimmer]

Don’t forget to have @HALIFAXHOPS recurve the dist your gonna run weather it’s a dual point or electronic conversion. As suggested b4 a modern torque converter will make it a totally different animal. The guys suggesting to stay with a stock converter are stuck way back in the 60s and 70s. Kim

 

[BSB67]

The guys suggesting to stay with a stock converter are stuck way back in the 60s and 70s. Kim

I recommend using the stock converter. You seem to think you know me and why I made the suggestion. Can you please share it with me and everyone else?

 

[oldkimmer]

Torque converter technology has come a long ways from the old days. They are way more efficient and u can run around all day with a 3000-3800 stall that performs as stock at low rpm and come on like gang busters when u got the pedal to the metal. They make drivability way nicer. Your car will be faster with it. Even better than just a cam change or a rear gear change. I couldn’t believe the night and day difference a modern converter made the first time I used 1. I didn’t say I knew you or your opinion. Like u I gave my opinion. Simple as that. Kim

 

[BSB67]

You said I’m stuck way back in the 60’s and 70’s? Did you not?

How did you come to that conclusion?

 

[HawkRod]

You said I’m stuck way back in the 60’s and 70’s? Did you not?

How did you come to that conclusion?

I don't think @oldkimmer was trying to attack anyone. I think Kim was just using the "stuck in the 60's and 70's" to drive home that torque converters can be built differently today than when these cars were built.

 

[oldkimmer]

You said I’m stuck way back in the 60’s and 70’s? Did you not?

How did you come to that conclusion?

I wasn’t attacking anyone but u seem to think so. We all have opinions.

 

[lewtot184]

This is what i thought about doing for a stroker build. I have a set of stage 5 ported heads on the bench. Flow numbers look like they are at least as good as OOTB edelbrocks. I've got a 6pak stuck back, spare block, new rods, and some valve train stuff. I need a crank and bearings, dampner and pistons and rings. Because the heads are open chamber I'd use a kb251 piston. I'd use a reasonable rather mild cam so the engine could run thru stock exhaust, converter, gear , and pump gas. Should be easy 12 second car if you can get traction.

 

[Dejavu1]

What was done to the engine in '99 besides cleaned up heads and new cam? If cam went flat that says something was off like the oil used...that was back when cams and lifters had good quality yet.

You're right. I know the oil played a big part in it.

 

[Curiousyellow71]

Just following up on what others have mentioned...
"If" you want to do new pistons, or perhaps it was bored back in '99 w what was available then? Make sure the machine shop uses a torque plate to hone it. Buying a forged piston w a narrower ring pack like 1/16 or metric, it frees up some hp over the wide 5/64 rings that it was born with. Not a lot..perhaps less then 10hp. There are several forged pistons that will make it 0 deck and have valve reliefs(a good thing) and will be 30% lighter. The original cast pistons for a 69 were about .050 down flat tops. Buy forged for this..I would NOT do a KB hypereutectic piston (They are still just cast). New pistons can be obtained with either a .990 bb chevy pin or 1.094 stock pin. The .990 is much lighter but requires a bushing pressed in your original Ly rod or you will need to buy a Aftermarket H beam...h beam is a substantial upgrade with larger rod bolts and much lighter.
Quite frankly if you get new rods and pistons...your a crankshaft away from adding cubic inches. Some of the cranks may need a little clearancing but if they run a 2.2" rod journal they nearly drop in. I don't really get the worry about building a stroker. Olds and pontiac and even chevy sold engines with near the same stroke as our stroker cranks. This is not a race engine, it will live just fine..IF you go that direction.

Guys like the stealth aluminum heads from 440 source cause if you paint them orange they are hard to tell from a 906. Most people you would have to tell them they were not original. They have closed chambers and would work well w 0 deck piston. Then you can run more compression and cam...w either manifolds or headers, the engine will still be matching numbers, and if someone wants to put 906s back on in the future they can. I like running the iron heads, but its more for nostalgia for me. The aluminum heads are a better fit for many people.

Other option for the heads would be getting more out of the 906...depending on what is done..it will make the stealths look cheap.

We just took apart our 440 based 510 after nearly 30 years. We have been shifting it at 6000-6500 all these years and internals looks like new. It would be awesome with a six pack on top of it. It had ported iron heads, Stock rods and a solid cam, stock damper. We also have a 542 stroker and several 440s. For driving, really can't beat the stroker engines. They have better street manners and loads of torque.

 

[dan juhasz]

I really appreciate all the replies. I'm likely gonna stand down on the mods. Thank you.

Hughes Engines makes a 6 pack specific camshaft. Notch above stock , needs no other modifications to the engine. I bought one a month back and was told at the time they have 7 on the shelf. Very pleased with the performance. Good luck.

 

[Loader]

Another vote for a different block. I've had my 44,000 mile A-12 hidden away for 30 years and am now in the build. For $400 I found another block so put my numbers-matching block and trans in the corner for safe keeping. There is a Tremec kit available to put a 5-speed in that includes everything you need - clutch, bellhousing, trans, adapter for shifter location, cross member, and a new driveshaft. So, now I'll be able to enjoy driving this beauty and not worry about hurting the block or trans. Now I'm thinking about swapping the K member and putting on disc brakes. Did you know the K-members are unique to the '69-1/2 Bee? I just learned that. Don't want to ruin it either and am not interested in a trailer car. This one will be driven!

 

[Bee1971]

Yes they had quite the K - Member and Intake Manifold display set up at Mopars in the Park back in June - Was very well done , and the gentleman that set it up or was talking was very knowledgeable and man did I learn some things about the A12 - Really neat to see

 

[dan juhasz]

Another vote for a different block. I've had my 44,000 mile A-12 hidden away for 30 years and am now in the build. For $400 I found another block so put my numbers-matching block and trans in the corner for safe keeping. There is a Tremec kit available to put a 5-speed in that includes everything you need - clutch, bellhousing, trans, adapter for shifter location, cross member, and a new driveshaft. So, now I'll be able to enjoy driving this beauty and not worry about hurting the block or trans. Now I'm thinking about swapping the K member and putting on disc brakes. Did you know the K-members are unique to the '69-1/2 Bee? I just learned that. Don't want to ruin it either and am not interested in a trailer car. This one will be driven!

Actually unless I misunderstood Darrin Stanke stated that the K member in an A12 were nothing unique ( other than it being date coded) . There were 3 K members used, true 69, 69 hybrid and 70 hybrid. But they were just bb k members.

 

[Big D A12]

Actually unless I misunderstood Darrin Stanke stated that the K member in an A12 were nothing unique ( other than it being date coded) . There were 3 K members used, true 69, 69 hybrid and 70 hybrid. But they were just bb k members.

This is correct. Dan passed the quiz at the end. We did the same presentation at Carlisle in the reunion tent. I doubt we will do it at any of the remaining shows in the tour due to access to the display area and availability of the 3 presenters.

D

 

[Dejavu1]

I know the temptation is there to add the stroker crank, headers and aluminum heads. I see lots of dogs with these mods and I'd be embarassed at the way a lot of them perform.
I prefer the Stock eliminator approach more. Head work, stock manifolds, better cam, light pistons and maybe even lighter rods. You see a stock looking A-12 and it runs mid 12's or better through the stock exhaust and that impresses you more than the obviously modded car that doesn't run any better truth be told.
I found that on the street a Hemi really works with a stroker crank working so well with the big heads. A 440 is a totally different animal and has to be finessed differently. Using stock heads you need to apply tricks to them and there's no use adding cubes.

Thank you. This is the approach I will take.

 

[hdwrench]

it sure is a tuff call . pro n cons on the issue . it’s a beautiful car .a440/6 is no slug , part of me say re fresh the engine and reinstall. part of me agrees w refresh the engine and save on an engine stand, build a beater engine to cruz with . keeping that matching block makes long term sense . either way it’s a great car to enjoy…

 

[velocityss1985]

Talk with Dwayne Porter from Porter Racing heads in Vermont. Nothing wrong with stroking the engine and getting a lighter rotating assembly. Dwayne can spec you out a killer combination that is proven and works with headers or exhaust manifolds. I like the sleeper look, as for the engine no one can see the internals. Rework your 906 heads and go have fun, build a torque monster. The 18-spline and Dana 60 are up to the task.