OK almost done with my machine work, specced out a cam (being ground now by Delta) and double-checking my numbers. This is a Wiseco/K1 motor, ported head 1.70/1.44, DCOEs, headers.

The car is my '64 Valiant cruiser/vintage road rally car with a 904 & 3.23 gears (may go to 3.55 and higher stall converter; eventually a T5 swap).

I went with CR and valve timing on the conservative side to help survive long freeway driving between mountain road stages. And to survive being flogged at high rpm for hours on end.

Let me know what you think:

https://docs.google.com/spreadsheet/pub ... 2QzTUREQ3c&

I don't see anything in there that is really scary, looks like a good solid build for driving. With the durations shown and the 106 LSA you may lose a little bit of manifold vacuum reading compared to a more conservatively ground cam so the carb will have to dialed for the drop off along with the vacuum advance, it's going to like to cruise higher in the rpm band. From personal experience the engine will really like the 3.55's, but pay attention to the drivetrain calcs and your OD ratio, on my duster I had to fill the Holley High Speed Jet to get the carbs mains to activate sooner, at 1700 rpm because the 3.55's/Tires/.73 OD tended to leave the carb in the transition slot causing a slow leanout at highway cruise and worse during lugging on slight inclines. If it's a .8 OD then 3.55 would be good to go.

-D.Idiot

The induction will be weber sidedrafts, so based on my previous non-slant experiences with them, I expect they will calm the idle and low speed running. Hopefully they won't have a problem with the cruising too.

Thanks for the advice on gearing.

With the sporty gearing the engine doesn't have to work as hard, and you can then dial in a slightly aggressive distributor curve...with the DCR in that range, you shouldn't have a problem running 87 normally and if you wanted a few more degrees for long distance runs you can make the bump and go to 89...

Should be a winner.

Do you have duration @ 0.050" numbers? Cam looks a bit small to me, esp if you will run IR carb/intake.

Lou

_________________
Home of Slant6-powered fun machines since 1988

236 intake 230 exhaust.

They are Comp Cams lobe profiles but I could never get Comp to answer their tech line so I sent the cam to Delta and they had those masters. The exhaust is the same lobe as the Oregon #791.

I am running 40 DCOEs I got from Rob, so I don't think I will be able to take advantage of higher rpm breathing from a bigger cam. I basically prioritized under 5,000 rpm power and picked a cam that I think will get me there.

If it runs out of breath I'll try bigger carbs first, then a bigger cam.

I was thinking that I would have to run 91 octane, do you guys really think it will run on 87/89 with some timing dialed out of it?

I will do the final tuning on a dyno so I guess I'll be able to find out.

I ran about the same DCR/little more SCR with the Erson 280/270 in a much heavier car, and I ran a total of 46-47 daily driving on 87 (run 18 mech+9-10 init+19-20 vacc adv.), got slightly better mileage running 52 on 92 (18 mech+14 init+20 vacc.), but the cost difference of the fill up did not offset the mileage gain. If the DCR were 9:1 or better you'd be doing super plus (my 12:1 race engine is at 9.3:1DCR and runs OK on super but will ping if pushed so it gets about 5 gallons of 110 when running at the track the cam is 250@.050 and runs better above 3500 rpm).


-D.Idiot

Should be very smooth on the low end with the cam, induction, comp you have there. I tend to err on the side of bigger cams myself. I would guess it should pull well to 5500 if headwork is well done. You will really have to thread the needle on advance curve and keep it cool to allow running with 87/89 octane. Run 91 (or your local premium) to be safer.

Lou

_________________
Home of Slant6-powered fun machines since 1988

i plan to tune for 91 octane. At my corner gas station 87 is $4.09, 91 is $4.25 - or less than 4% more expensive. It doesn't make sense to use anything else.

If I will be leaving power on the table I could always use a shim gasket instead of a Felpro.

As I understand it, the 40s on a 225 would be a lot better for torque rather than high end horsepower. Have also read that DCOE's have no provision for any kind of vacuum advance - strictly initial and mechanical advance. I've got a set of 40s I've had for a few years now and am considering using them on another slant I have. Just out of curiosity, what kind of numbers are you running for main, idle jets, emulsion tubes, etc?

_________________
65 Dart station wagon slant 6 - now under construction
47 Dodge Custom 4 Door sedan
87 D100 Short Bed slant 6

Retired USAF 1966-1986
Retired US Postal Service 2004-2014

DCOEs have no ported vacuum source, so yeah I'm building a distributor with no vac. advance.

I have not even looked at my carbs since I bought them to know what parts are in there.

I have tuned Mikuni sidedrafts before so I'm not too worried about getting them to work properly.

I'll be sure and report back when I get them set up.

New numbers.

I ground the combustion chambers to match the bore, and re-cc'd them. I got smaller numbers than last time (but repeatable??) so I must have done something wrong before.

Anyway, I checked the piston pop-up and it was .0025 (with no machining on the block), so I dropped the block off at the machinists for a .0075 cut for a total pop-up of .010. I am going to use a thicker head gasket instead of the shim gasket I was planning on.

CR bumps up .25 or so total from the changes. At 6 degrees advanced (100 degrees intake centerline) my DCR is 8.78. At 4 degrees it is 8.66.

https://docs.google.com/spreadsheet/ccc ... sp=sharing