Tried and Tested Engine Combinations for 12s?

[Andy]

Hi, I am planning a new street and strip car that ultimately I want to run 12 second quarters.
So far I have a low mileage '67 that I will strip out but wont be cutting any metal and I plan to use a close ratio box that is still streetable. The car will be driven locally and probably to the drag strip 130miles each way, although if it needs to be trailered it could be.

So as there are lots of knowledgeable people on this site I thought I would ask. What are the reliable engine combinations that will enable me to achieve my goal. I was thinking of 2276 or 2332, are there any issues of using the 84mm crank over the 82mm.

Heads, I was thinking of 044s, mini wedgeport, wedgeport or ultra wedgeport, which ones would be appropriate, what valve sizes and are there any better choices of heads.

Cam choice is probably the hardest thing to make, would an FK10 be enough, what about an FK87 would it be streetable and what about the Web cams, how do they compare to the Engle cams. Which cams need the longer valves.

Thanks

[Jim Ratto]

Car looks pretty cool from your small avatar pic. Can you post some more shots of it?

I would say with the availability of some pretty stout parts for street motors today, building a "12's motor" can be done failry easily.
I ran 2276 with 44 x 37 VW heads with conseravative ports (sideways D port by Jeff Denham), 9.3:1, Web 86C, 48 Webers, etc. Car would run high 12's consitiently, in hot weather on slicks. Best was 12.66. gearing was 1.48 3rd/1.14 4th/4.37:1 r&p.
This motor was very streetable, I used it to commute to college and work a few days a week. Gearing was not so "freeway-able"
I'd think twice about close gears if you have a 130 mile drive to wherever you're going. Unless you're going to add a 5th.

2276 or 2332 will do plenty of damage at the strip, if you get car to hook up. With that much power, you can end up frying the tires out of the gate and run a slow number (been there). I'd on the cam, with the extra torque the 2276 or 2332 will give, you can up the cam from the FK10, and go with FK87 or Web 86C. The 86C in my car was explosive. Longer valves might be a good idea, as I found conventional VW dual springs would die soon running 1.45's on the 86C. I think it overworks those little springs.

[davvide]

maybe is off topic but there is any relation from hp and  1/4 mile?

in totally street car

[Jim Ratto]

maybe is off topic but there is any relation from hp and  1/4 mile?

in totally street car

yeah there is a formula I used to have somewhere, inlvoled cube root.
For the life of me I cannot remember it or find it.

[Andy]

Here is my car from the Avatar, it is a 71 1200 which was the base model over here so the tail lights and bumpers are correct. I did a full body off resto on it. A mild 2110, too mild, powers it, the best I have got out of it is a 15.4 so it may receive a bit of work over the winter, I have a Pro Street box to fit anyway.




This is the '67 that I have a half share in and will be the 12 second project, it has not previously been restored which is pretty rare over here and only needs a small amount of welding. That means we can concentrate on the drivetrain 

[Jim Ratto]

Both look look like real nice cars. I really like the color of the '71

[Andy]

Thanks, the colour is still one of my favorite aspects of the '71

[leec]

I cant recommend enough the set up I have.

2276cc, Wedgeport Heads, FK87, IDA's and a cog box gearbox. (Not ultra close)
Engine Built by Matt Keene with full blueprint and 10.3:1 CR

This combo has run 12.4@11mph, with 185 Khumos and 12.1@108 (hot day!) on slicks.

I do Aframe the car to the track, but has been used on the road with no issues, other than noise!

The cam is perfect on the street, kind of wish id gone FK89 now!

The car is a 56 oval, full steel car with stripped interior.

Lee

[Andy]

Thats good information, Lee, I've seen your car on various forums and you are running impressive times.

Do you know if you are running a cro moly mainshaft in the gearbox, I wonder what the life expectancy of a box is when it is in a 12 second car.

Are the valves longer than stock.

Is anyone running an FK89 on the street, I take it this will push the power to even higher revs.

Also How does an 84mm crank, such as the CB performance one, with chevy rod journals compare in strength to an 82mm with VW journals, I also hear of a Type4 centre main bearing being used with an 84mm crank, what is the advantage of this.

Thanks
Andy

[leec]

Gearbox hasnt got a chromoly mainshaft. Its done about 6 meets (7-10 runs a time) on it and has been fine so far! It was a comprimise box (In no way that its a cogbox box) as I ran low on cash and a new, never used box came up cheap second hand.

The valves are stock length. Matt had to spot face the heads to get enough valve lift. CB want you to upgrade to the LS1 spring valve/spring combo. Out of the box the wedgeport heads wont allow you to run a lot of lift at the valve.

Lee

[hector]

i use a 2276 ,fk89 ,jeff denham 043's 10;5;1 compression and its a real easy drive on the street , never goes over 80 degrees , runs 12,3 on treads  my 2 pence worth
hector

[besserwisser]

If motors were like recipies in a cookbook every Tom Dick and Harry would run low 12-s with just of the shelf parts. Unfournatly that s not the way it works. its all in the combo and how well you assemble the parts and what you do to the parts. Ive seen parts bought and just put together as big as 2332 cc that dint make more than 120hp. To run 12sec in a all steel car you need around 180 to 200hp. You need work on the chassie to handle the horsepower. You need a gearbox that will handle the abuse.  The variables in a motor are so many that just one thing wrong and you wont hit your target. The strange thing is that you can buy all the same parts that youre buddy is running but you wont be even close to his times if the parts dont work well together. I do this for a living but sometimes I just dont know why one engine works so well and the other doesnt. Maybe thats why its so interesting, to uncover the mysteries of combustion engines.

[Andy]

Thats a good time you have run, Hector, what spec gearbox do you use, also what brand barrels and pistons.

Andy

[hector]

the b&p's are just mahle ones and the box is a cogbox close ratio one ,im not sure on the gearing but i know it goes over the line at about 7000-7250 rpm,and it sits about 55-60 on the motorway cruising speed

[Andy]

Cool, I was just checking the pistons, as the CB 2332 engine kit uses Wiseco pistons.

Anyone got any opinions of the 84mm verses 82mm cranks, does the bigger stroke and chevy journals of the 84 give up any strength.