Slant Six Forum
https://slantsix.org/forum/

1963 D100 Truck Build
https://slantsix.org/forum/viewtopic.php?t=59193		 Page 1 of 1
Author:  63UtilineSlant [ Sat Feb 27, 2016 12:49 pm ]
Post subject:  1963 D100 Truck Build
Hello Slanters,

In this thread I will be sharing details of my truck engine build, as well as seeking advice and feedback from you all.

This forum has been a great resource for me as I started to acquire parts for my build, and I hope by sharing my experience I can contribute something as well.

I bought an old forestry truck (originally from Oregon) a few years ago in the California East Bay area. The engine smokes and burns oil like crazy, and a constant mist pours from the crankcase breather while it simultaneously weeps from the cylinder head and valve cover gaskets.

In spite of all of this, it still runs ok, and I've helped several friends move heavy appliances and furniture. The engine rarely sees north of 2500 RPM, but with 2.93 gearing that works ok (someone swapped out the stock 3.90 sure grip for open gears in a 489 case)

This dependable slant has made several trips up Priest Grade to Groveland, and even hauled an 18' boat around town, though I couldn't get it over 45 mph.
Image

I've finally parked it and started to tear apart the engine, and I have a whole cabinet full of go fast parts. The current plan is to build a fun engine for scooting around town, while I look for a good core for a fuel injected turbo build to put together on the stand.

With that in mind, I currently have a ready to go cylinder head with 1.75/1.50 valves and 49cc chambers, Offy and Clifford 4bbl intakes, clifford 3 to 1 truck headers for my low starter NP420 combo, a new in box holley 4160 390 cfm, a rebuildable 570 cfm holley with vac sec from a C body with a 440, HEI setup with a 18 deg mech adv distributor, and most importantly, all the parts for front disk brakes.

All that's left before I send the block to the shop for machining (besides dropping the NP420 and yanking the thing) is the cam selection. This is where you guys come in! I'm not sure if I want to stay with something relatively mild like a Howard 255 with compression in low 9s, or go more aggressive with something like a Racer Brown ST-22 and 10:1 compression. Truck is 3600 lbs and mostly for scooting around town and trips to the hardware store. I don't plan to haul anything. I'm a "spirited" driver and tend to drive all of my cars as if they are Porsche 944s.

I threw together a spreadsheet to help with cam calculations. I also have a sheet for gear ratios. I hope some of you find this helpful, as well, and can provide me with some feedback on what improvements could be made.
You can download it at this link
http://www.filedropper.com/camselectionslantsix

Here is a link to the truck photo album. I will be updating it as I progress with the build. Right now there are just some shots of the truck, the new cylinder head, and some of the teardown.

http://s24.photobucket.com/user/moparma ... /63%20D100

I look forward to hearing your thoughts and opinions.

-Isaac
Author:  wjajr [ Sat Feb 27, 2016 1:36 pm ]
Post subject: 
Welcome aboard.

I have a somewhat built slant that at onetime was a 1/4th mile drag queen. It has now 3.55 suregrip rear and 24.5 inch tall tires. One problem is my power band starts about when the average two lane road speed limit (55mph) is reached so it is a dog putting around town, and loafing along at 45 mph. She will spin up to 6000 rpm pulling like a 318 past 4200 rpm, but kind'ah lazy for the first 3000 rpm which = 60 mph.

Try to match your torque curve to the speed / rpm you will be traveling at most of the time so that your truck will be responsive or spunky most of the time.

Also I believe turbo engines prefer a taller rear gear around 2.00 vs. a hot cammed naturally aspirated engine that needs high rpm to make power and a low gear rear say in the 3.55 to 4.11 range or lower if you have real tall tires.
Author:  DusterIdiot [ Sat Feb 27, 2016 1:57 pm ]
Post subject:  Lol...
I had a co-worker that had one of those trucks but still had the 3.91 gears...I think his top speed was 45 mph...

I think we should retool your thinking due to the weight of the truck from go-fast, to 'more torque'...

You have the right idea, and staying in the 9-9.2:1 range would be best especially lugging that truck and the highway gear ratio...

There will be a fine line that can be crossed if the components aren't matched right....

If going torque route, 9:1 SCR, one of the cams like the mopar Performance 244, or the OCG 818 (108 lobe separation, centerlined closer to 102) would be good...using the Offy intake with the 390, once tuned in will get you a fair increase in umph with good gas mileage...going with the 2.25" exhaust pipe is fine... you can also use regular gas with this setup when it's all tuned.

Looks like you got a later head so things good there.

An EI distributor and ignition system is a good change, you will need to recurve it to get the most out of the new build, the stock curve will be a little lazy...

Headers are optional... you may want to do a test fit to make sure that they will work with the low mount starter, most of them tend to have one of the tubes dump out where the starter sits, and on that generation of truck, there isn't a mini-starter available to give you a few more inches of space.

If you go that route, the O/S valves will work as long as some porting and bowl blending is done...if you get too enthusiastic then you'll lose your bottom end torque and it will be doggy at street rpms...Looking at the pics, no bowl work has been done and the material around the valve guide needs further work for better flow...

Be wary that without the heat stove using the headers it might be really cranky starting up on colder mornings....

If you go with the 10:1 build, you will need to figure out how to drop 800 lbs out of the truck, or get those 3.91's back and get an Overdrive...as that build will require a cam that will put your power band at a high rpm... but will be very nice on the highway... if using the granny gear NP transmission, the granny gear may help but the ratio spread may dog the engine on the upshifts...

Going to a 570-600 cfm carb is great for the track...on the street you will like the power, but a stock 360 or big block car will pass you at the gas station.

Make sure your hydraulic clutch system is up to snuff, they are fine for utility work, but the 1960's system is a little slow for "spirited" driving compared to the later hydraulic systems and stock mechanical linkage.


You will have to commit to which route to take with the vehicle, and how many other components will need to change to accommodate the build.
Author:  SlantSixDan [ Sat Feb 27, 2016 2:11 pm ]
Post subject: 
Welcome here. Neat truck. In your position I'd be going for Dutra Duals rather than Clifford headers.

Other stuff to look at: HEI ignition upgrade, hi-perf engine buildup here, high-perf parts and build info here.
Author:  63UtilineSlant [ Sat Feb 27, 2016 2:38 pm ]
Post subject: 
Thanks for the response.

I'm planning to change the rear gear ratio to match the power band of the engine and the wide tranny gearing, something closer to the stock 3.91 with my 30.39" tire diameter. This should make the hotter engine livable but you may be right that I will prefer the more mild cam for just cruising around. Honestly, though, I guess my biggest concern is not driveability so much as safety with the 30 lb 11" truck flywheel. If I put in a hot cam, am I just tempting fate by spinning my engine that fast?

To compare cams and power bands, I have been using an old copy of desktop dyno 2000. I made a baseline build with stock specs and adjusted my head flow curve until I got close to stock #s - 208 TQ and 115 HP. It shows a curve with torque dropping off around 3000 RPM which is pretty much how the stock cam feels to me.

The RB cam looks like it pulls to 6500 and has peak torque at 4000-4500 RPM, while still maintaining about stock level of torque at 2000 with the upgrades and 10:1 compression. When I look at the power curve it looks a lot like my 99 VR6 Jetta power curve (only shifted up). That car is only 3000 lbs but is a lot of fun to drive and never feels sluggish. I realize a lot of that is the balance of weight and gearing.

The Howards cam (on custom centerline) looks like it pulls to 5500 and has peak torque 3000-3500, with about 15% more torque than stock at 2000 with same upgrades and 9.4:1 compression. The idea of having a bit more torque than stock is definitely attractive, and keeping the engine below 5500 is probably the best choice safety wise with a stock flywheel.

I reread what I wrote about building a turbo and I realized it was pretty unclear. I have some parts for a nice, relatively high compression NA slant right now, which is what will be the current build. In the meantime, I'm collecting parts for a fuel injected turbo build, which I expect is at least a couple of years down the road and is my ultimate goal for this truck. I intend to use the Offy manifold for now, while I prep the Clifford manifold for EFI.

My first slant six was a 62 Dart that I got about 14 years ago. It was a stock rebuild with a Comp 264 cam and pertronix upgrades. 3.31 rear and I can't recall the tire diameter but it was about 75MPH @ 3000 RPM in 3rd gear. That car had plenty of torque down low but with stock intake, head and exhaust it choked out around 3600 RPM even though it would rev to 5000. It was still a lot of fun to drive.

Somehow the bug bit me and I always wanted to really build a nice slant ever since owning that car. Sadly, I had to get rid of it while I was in college but I eventually found my way to this truck, which I bought specifically for the fact that it had a slant six.
Author:  63UtilineSlant [ Sat Feb 27, 2016 2:51 pm ]
Post subject: 
Whew, a lot to catch up with. Thanks for the responses.

DI,

Thanks for the heads up on header fitment. I will also check out the cams you mentioned.

The valves on the head seem a bit big, but the price was right considering the machine work done so I snapped it up. Unfortunately, I noticed that the ports are opened up to gasket size, so I was concerned about that being counterproductive for low end, and that pushed me towards bigger cams.

I lucked out and got a distributor with 9R governor so that lets me run 12 initial 30 total which I read is what the slant likes. I have a spring kit from BigSlant Fan so I plan to play with the curve when it all goes together.



SSD,

Thanks for the links. The HEI guide has been very helpful and I really appreciated the inclusion of the napa part #s for the relay. I already have most of the parts you spell out (still need new wires) and also machined an aluminum plate with all of the holes to locate and mount the coil and HEI module.

That thread on the Twins buildup and the aluminum buildup have been great resources for me as well. It's been a while and I should probably review them. Thanks for including the links.



And thanks to all for the reality checks.
Author:  DusterIdiot [ Sun Feb 28, 2016 8:50 am ]
Post subject:  But...
Quote:
Unfortunately, I noticed that the ports are opened up to gasket size, so I was concerned about that being counterproductive for low end,
That won't bother anything, what will kill the flow is the port transition where the valve guide is at...it will be the bottle neck for the flow.

A few other thoughts to think about:

There will not be a problem with the stock 11" clutch and flywheel (it is similar to the big block flywheel and can use most of the same performance clutches), unless you have an all out Turbo build. With the extra weight it may not rev up so fast after the upshift. Crank weight also will play into this, as the 1963 crank is heavy compared to the late forged cranks in the mid-70's... (and the cast cranks of 1976-1987 are lighter than those)....

You might look to installing a driveline loop as a 6000 rpm clutch dump will most likely stress the U-joints more than the clutch assembly.
Page 1 of 1 All times are UTC-08:00
Powered by phpBB® Forum Software © phpBB Limited
https://www.phpbb.com/