I am after suggestions regarding building a replica of the Slant Sickness engine.
The car is '69 Valiant 4 door about weighing about 3000 pounds
Weekend toy, street fun car
No nitrous
Currently 3 speed manual, but like the idea of an auto trans
Currently has 3.23 gears and 25" tall tyres
The differences in the engine build
600 Holley vs 625 Demon
Different headers
Head ported by myself, still large valves though
possible different cam spec


Any thoughts on driveability, diff gears, converter, cam spec?
Any comments welcome
Thanks

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Richard (aka Fingers)

mmmmmmmmm 67 views and no comments...?

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Richard (aka Fingers)

No comments may be because you have a fairly vague set of parameters listed there. You are speaking of the Hotrod mag engine?

What sort of performance are you after? Economy, cruising, dragstrip passes? 15s, 14s...?

Lou

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Home of Slant6-powered fun machines since 1988

I could write a magazine article on this question... (we did)
http://www.slantsix.org/articles/hrm-sl ... ckness.htm

Your basic plan is fine but matching the cam to the head work and intake manifold is the key to a successful SL6 build-up. Give us more info on your drivability needs and we can give you some detailed advice.
DD

Sorry, I meant " building a replica of Slant Sickness magazine article engine"

The differences to the magazine build are noted

The Holley instead of the Demon, mainly because I already have a good condition 600 holley

The headers because I have a set already on the car (and the Cliffords wont fit, even if they were available in Australia)

The head I will port myself and have machined for the bigger valves

Cam spec is open to suggestion

I have a Hyper pak, electronic distributor, various 225 slants.

The car is a weekend use, street hottie, that might see the quarter mile just to see what it does.
Some open road cruising is on the cards, so rear end ratio needs to be no lower that probably 3.5 or 3.7
Fuel economy and a smooth idle are not important.
A bit of WOW factor is important. (the main reason I wanted the Hyper pak)

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Richard (aka Fingers)

With The Hyper Pack you will get a smoother Idle - Even With some of the bigger cams - you will get Decent fuel economy - Espically on the Hiway and you will also Get the wow Factor.

My car runs the equivalent to.562" of lift at valve with 284 Duration - with a 3.2 Rear I get 21 MPG Hiway and with 4.10 Rear I run 15.05 with A fully loaded stock barge.

Most of the power will be founf in the head - I spent the cash and got mine done prfessionally - I just did not want to screw it up. I also got some bigger valves and cut the head down .110" and cut the block .100"


I still run it on the street. It's great.

Greg

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http://www.youtube.com/hyperpack

Greg,

Does you attribute the driveability (even with such a large cam) to the ram-tuning effect of the Hyperpak at lower RPM bands? (And the resulting improvement in torque).

-Mac

Thats a good question Mac.
Greg, if you were to build your engine again, would you change anything, or just do an identical build?
Also good to hear it is driveable with a pretty big cam and 3.2 gears.
How do you think it would cope with a 904 rather than a 4 speed?

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Richard (aka Fingers)

Mac,

I have no hard Evidence to back it up , but I guess it is due to the ram tuning effect. - the Torque in the 2000-4000 RPM range is tremendous. Due to the torque being so good in the mid range I am assuming that is how it gets such good mileage - It can spin slower - Use Less gas and still make more power. Doc actually has dynoed some h- Pack Engines with an Above 100% Volumetric Effecincy Rate - it's posted on here
http://www.slantsix.org/forum/viewtopic.php?t=18685
http://www.slantsix.org/forum/viewtopic ... light=dyno

Vg-265,

I suppose anything will work with the trusty 904 - You just need to get a converter to match your cam, and Rear Ratio Combination.

I also have built this engine in stages - as Time and Money has allowed.

I have had thew car for about 7 Years now, And have started with a stock 225 and Just the intake and Headers - It will run, but there was always atremendous flat spot.

I then went to the mopar .460 Cam - That made a big difference - With a 4.10 Rear it would run 17.2

Then I got the Head and block Decked as mentioned before - and Larger Valves with porting work too. I dropped a full 2.0 Seconds off the 1/4 Mile time. Since then I have had The intake Extrude Honed - i went to the MP .528 Cam and Added Roller rockers 1.6 Ratio.

So in short - I did not build it like that - It sort of evolved As Money allowed and My need for speed grew.


More Info can be found on the current Setup Here
www.geocities.com/gao5498/slant6

and Here
http://www.slantsix.org/forum/viewtopic.php?t=13007



Greg

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http://www.youtube.com/hyperpack

You do not need a hyperpack for drivability with a big cam on a 225. 225s can use a LOT of cam and still be fairly docile down low. Key is getting high enough comp and a good ign advance curve.

Don't even think about compression lower than 10:1. If it is really a limited use car, then 11:1 would be fine. I have run 10.5-11:1 on the street for years with no problems. Matching high comp with a big cam is the way to go.

Lou

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Home of Slant6-powered fun machines since 1988

OK, So with the Erson 270 I had planned to shoot for around 9.5:1. Are you telling me that I need to go higher than that? Initially I'll be running a Super Six, Torqueflite 904 with stock converter and 3.23:1 final drive ratio. If I go to 10.5:1 what octane fuel should I expect to use?

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David Kight
'62 Valiant Signet, White
'98 Dodge Dakota
'06 Jeep Liberty

Growing older is unavoidable but growing up is strictly optional.

I run 87 with a comp 264/9.25. The erson 270 and 9.5 should allow 87.

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Yeah....Im the one who destroyed this rare, vintage automobile.....