The title says it all. Thanks for all the helpful advice and invaluable amount of information available on slant6.org.

I have been working on this project for a couple of years now and it finally has come together. the motor sounds great and pulls strong up to 4500rpm. The build sheet is as follows:

Cast crank 1984 block w/ arp studs top and bottom
k1 rods
kb268 pistons (3.445" bore)
NOS purple shaft hydro cam
engnbldr oversize valves
ported and flow tested head
aussiespeed hurricane intake w/ eddy 500cfm avs carb
dual exhaust headers into dual 2" pipe
cherrybomb elite 2 into 1 muffler with 3" tail pipe (nice and quiet)

This went into a 84 d150 with an overdrive 4 speed. I am very pleased with the power gain as the tired old slant was basically done making power @ about 2500rpm. This thing is a rocket now (well as much of a rocket as one could hope for out of a torquer motor). Driveabilty is nearly perfect with a steady idle and 19" of vacuum. It really pulls steadily through the power band and reaches highway speeds with ease.

Thanks again!
Noah

Be very interested in your cam specs?
Rick

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

240 advertised duration
.395 advertised valve lift

I measured actual valve lift @ .375" with all the lash taken out of the lifter. duration @ .050" valve lift measured 174 degrees

edit: lobe seperation is 108
installed camshaft @ 108 intake centerline

Congrats! Always great when a project comes together...

Lou

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Home of Slant6-powered fun machines since 1988

the KB 268 is the dished piston correct?
any other changes to the combustion chamber volume?
have you checked or calculated compression: static, dynamic, cranking..

looks like a nice package that you put together..

SLANTEDRAM,

Any idea on compression ratio? and how much you decked the block?
cc's on the head?

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

The combustion chambers measured 56cc's. the block has the stock deck height and the kb268 pistons are about .003" in the hole. Static compression is 8.9:1. Dynamic compression came in right @ 8.0:1

The kb268 pistons are 18cc dished pistons.

Awesome!

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

Thanks Ted. It was a very long and drawn out build up. I have found that piecing together an entire engine is a little more of a project than your average "rebuild". I have the old motor still 100% complete on the stand as a spare

This is a pretty good "street performance" long rod combo, that works well... "right-out of the box".
Good work getting your build together "by-the-numbers" and sharing the results.

It's too bad there is not a better supply of 198 con rods...
If factory 198 con rods were as common as 225 rods, I would always build long rod 225s. (Higher static compression with-out a lot of "milling work", lighter piston, thinner ring pack and a better rod ratio)
DD

Keep us posted on how it compares to your stock one on gas Mileage.

Thanks Rick

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

sure thing rick. gas mileage with the old motor was consistently around 15-16mpg- this was running a super 6 carb and manifold with single exhaust going through 1 cat converter.

I am still in the tuning process on the new motor, but I suspect that if i can keep my foot out of the skinny pedal it will do pretty well

what grade of gas are you tuning to?

Will be interesting to see where the advance curve ends up.

The compression ratios that you list: 8.9 static and 8.0 dynamic are in the same neighborhood as what I have calculated for my build, I am looking at 8.5 and 8.2

Today was the first day that I have gotten enough miles on it to see how it behaves in normal driving conditions. I had put too much timing in it and it definitely will ping with 40+ degrees of timing

Right now I have 93 octane in it, however, I will slowly work it back down to 87 to see how it does. timing is now @ 34 degrees @ 2500rpm with no ping @ all and seems like it might like 36 to get the timing up to about 12 @idle .

I have not connected the vacuum advance yet because I wanted to get the base timing set first. I think it will respond well with the addition of some more advance @ cruising speeds though, as it really ran well with 40 something degrees of mechanical advance

What were the numbers when you flow tested? At what pressure? 2.5" HG?

I've found that my long rod stroker will tolerate a tremendous amount of timing.

Currently running 22° initial, and 36° all in. With 10.7:1 compression and a gnarly cam, I can put a gallon of 110 in with premium and won't get detonation. It likes it at the strip.
It will however end up with high head temperatures with large amounts of advance. Don't get too carried away with the timing if you street drive it. The oil temperature will rise, and idle pressure will drop to nothing.

2¢

CJ

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Part of Tyrde-Browne Racing