i would be interested in flow numbers also as i am in the middle of porting a head for my car.

also why was the decision made to use a stock distributor? i have heard there is power to be had by recurving.

on compression, my fsm says the cr is 8.4:1 but 7.5 sounds more believable. a friend built a slant and shaved the head and the block and still only came up with 8.25:1 after cc'ing everything.

zedpapa

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1970 dodge dart w/225 /6 bored .040" over, holley 390cfm w/vac. sec., compcams 252s, clifford shorty headers w/2.5" exhaust w/flowmaster, f-body 11" front discs, aluminum A-833OD, 8 1/4 w/3.21 SG
soon to have 5 gears!!!

I just posted the flow numbers.

As to the distributor:
Romeo (the engines owner) provided a distributor that was already setup for racing, so we just used it for the dyno test using a carb. Besides in a race engine I usually just run fixed timing so who cares about a curve anyway.

The EFI setup required something entirely different. I could write an article on just THAT. I modified a unilight distributor to create the CAM signal (once per two engine revs) and then we usually use a crank trigger for the actual spark timing. With EFI the crank trigger is set up at a FIXED 50 degrees BTDC and the ECU takes care of computing the actual spark timing that triggers the MSD.

BTW, somebody questioned the 7.5:1 CR that was stated in the article. Truth be known we didn't cc the stock head to compute an accurate stock CR. We just did some rough calculations and all I remember is that is was VERY low. It may have been 8:1 or so. The engine was pretty dirty so I was eager to just tear it down, clean itt up, and get started with the project.

dang. you beat my flow.

http://www.slantsix.org/forum/viewtopic.php?t=13881

No we didn't. Your flows and our results are almost EXACTLY the same, considering flow bench variances etc. Nice work. Did you dyno the engine and have you raced it yet?

no, haven't had a chance at a dyno or on the strip yet (I was laid off....just started a new job about a year or so ago now) and my money has had to go to the essentials, so the duster has had to sit. I have spent the last few months getting all the parts gathered up, so this spring I can send it off to the machine shop once I get my christmas bonus. The plan is to deck the block again, and have the entire assembly balanced. If you are interested I can let you know how it all turns out once I get it back.

If you know a machine shop you would recommend in Minnesota let me know! The CNC I run at work doesn't have a large enough Z axis to get the block in there (I work for a plastics shop and am developing custom dash clusters for a-bodies in my spare time).

I am really looking forward to getting my hands on this issue but it hasn't hit the stands here yet.

Rich, how did you like tuning the FAST system.
A couple of guys at the local speed shop said it's one of the easiest systems to work with for quick dial in, due to ease of the interface and sensor information (one uses it for a built 390 FE).

Since I'm working toward the EFI Hyperpack long rod, it will be interesting to compare numbers...so far everything you produced has 'borne out' on what I had theorized while doodling formulae and notes in the sandbox...It'd be interesting to see that same build with a roller cam to see if it would yeild a few more gains.


thank you for sharing.

-D.Idiot

*edit* I just realized this probably doesn't belong it this thread; I should have started a new one. I've reposted in "Other"

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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.

Rich,
Thanks for the flow numbers. Your .500 fall right in line with all the head flow data I have seen so far except for one head. The heads we are porting for the simca are ported with the low numbers in mind and we are not concerned with anything above .500 lift. You can reallly improve the exhuast and I will dig up the last head numbers we did and post them.
Great write-up by the way and be sure and keep us updated on your slant 6 work.

Head .100 .200 .300 .400 .500
stock 55 94 124 147 158
Lou's 81 127 163 183 187
Sim1 82 131 171 187 196

Tom

PS - Was the 10K price including both the carb and EFI set-ups or just one?

_________________
Nitrous cars are like old men on Viagra. Once the bottle is empty they are useless.
FJD

D.Idiot

I've been programming the FAST system since it's inception, and I feel it's very logical. But I'm an electronics engineer by education, and I used to design EFI systems, so I'm "not normal". Some of my customers who feel they are not computer literate, still need somebody else to do the programming. Everything in the FAST system makes sense, but you must be comfortable with the terminology and the basic requirements of an engine.

I am currently assisting FAST in trying to write a "hold your hand" document that will walk users through the process. Their current documentation is only in the help section and does a good job of installation and setup, but leaves you dry when you get to the big question, "What should I do next?"

With a few $10K slant six race motors in the works, it would be
interesting to hear a collective wish list of features for a custom
head. Specific features like chamber shape. Not that anyone
here would be spending $4,500 for a special race-only casting,
it appears that a select few can afford to think about it.

I'd like to see the head science as a detailed spec as only a guru
with seasoned race experience could know. I suspect that out
of a dozen racers there would be tradeoffs favoring one design
over another. I say this as I think that people will care about
the quirky slant six for decades, eventually a race head casting
may come to fruition.

This Eisenhower era technology can continue to adapt. The Hemi
is Truman era technology and is still beating the pants off the
competition.

Tim, the problem with getting 12 Slant racers together is that you would end up with at least 10 different opinions on what to do.

Rich, thanks for posting the head numbers. Mike won't even tell me what the ones are for my new head.

_________________
Official Cookie and Mater Tormentor.

Lous head above was the head Mike did for him flowed on the same bench we flow ours on. 28" of H2O and I think Mike flows all of his at 10" because of the bench he uses. You can convert the numbers but with the high inches of H2O you will find turbulence if there is any.


Tom

_________________
Nitrous cars are like old men on Viagra. Once the bottle is empty they are useless.
FJD

I believe Mike's bench is 14". I don't think you can reliably convert the numbers, but it may work in some cases.

Lou

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Home of Slant6-powered fun machines since 1988

Thanks Lou. I could not remember what inches he flowed at. You can convert different scales but even the flow bench companies will tell you it is not accurate. They even tell you flowing on different benches of the same type is not all that accurate either. The only way to really compare flow numbers is to flow the heads on the same bench. They even tell you to be careful if you have to change scales during the middle of a head.

All of the numbers I listed above were flowed on the same Superflow 600.

_________________
Nitrous cars are like old men on Viagra. Once the bottle is empty they are useless.
FJD