Intro: Another "obsolete" engine going propane.

[51geezer]

I've already posted but I should pause to tell you guys a bit about my project.
I have a '66 F100 with the original 352 FE with a 4V carb added. It makes pathetic power and sucks gas, so a change is in order.
The stuff I have to remedy the problem:
- 352 FE + .050" block and 3.98 crank for 410"
- cheap pistons (390 truck item), should give about 10.25 CR
- Comp 265DEH cam
- Streetmaster intake
- Impco "E" vapourizer
- tanks and hoses
The stuff I still need:
- Impco 425 carb - proving hard to find used, I might buy a new one
- tanks that will fit inside a 34" frame
- more money

That's where I am today.
Eric

[storm]

I like it when people keep old engines running with LPG, keep us posted with your progress.

[TroyT]

I assume that is a Ford crank? One thing to keep in mind it factory 3.98" cranks are externally balanced while all other FE's are internal. You will need to either have it internally balanced to the rest of the rotating assembly (best choice but expensive) or use a counter weighted flywheel/flexplate.

Streetmaster is a good choice for your combo.

[51geezer]

Thanks for your interest.
I haven't gone missing.... I'm still looking for a suitable tank. The narrow 34" frame is the stumbling block.

Yeah, the 428 crank will require that I get the 352 flywheel balanced with the crank. I think I will go with less cam to move the powerband down and add a little more cylinder pressure. I am on the scrounge for the uncommon Q-jet intake manifold, but as finding one is unlikely, I'll probably stick with the Streetmaster.

So, I might have found a used tank: "Siamesed" 30x13" with hoses, affordable. What should I look for when I go for a look? Is there an expiry date on these tanks? Is re-certification unavoidable?

Tanks, Eric

[C3H8]

This is the exact code on reinstalling tanks and the period for tank inspections.

5.4.9
Prior to being returned to service, a tank that has been in service and is being reinstalled, or installed on
another highway vehicle, shall be inspected and requalified in accordance with one of the following
methods:
(a) When the tank was previously installed in an enclosed space protected from the environment and
the tank shows no evidence of general corrosion, line corrosion, or isolated pitting, and when all
details of the manufacturer’s specification plate are legible, the tank shall be re-examined and
re-marked in accordance with PGAC 200-02.
(b) When the tank was previously installed in an area subject to environmental corrosion and the tank
shows evidence of general corrosion, line corrosion, or isolated pitting, and when the tank does not
meet with the reinspection requirements specified in PGAC 200-02, the tank shall be re-examined
and re-marked by an approved facility, cleaned to bare metal, and have its exterior refinished with a
protective coating.
5.4.10
Re-examination shall be made only by qualified persons acceptable to the authority having jurisdiction,
and the results of re-examination shall be recorded on a data sheet that contains provisions for recording
the size of tank, inspection location, manufacturer’s name, date of manufacture, serial number, CRN
(Canadian Registration Number), date of inspection, and inspector’s initials, and whether the tank was
returned to service or removed from service.
5.4.11
Records showing the results of reinspection and retesting shall be kept by the facility carrying out the
inspection for a period of 10 years.

[C3H8]

Part 2 of the previous post. Conversions must be inspected every 5 years as dictated by the code. See 5.13.4. The last sentence in this post. These are the codes from 2010, however other then some amendments and minor additions they are the same for 2015 and 2020. The main changes are codes referring to fuel injection and the change allowing two tanks to be filled from a single source. These codes are Canadian of course. The US has similar codes.
5.13.1
When a vehicle is converted to run on propane fuel, a label of approved design shall be affixed by the
installer on the inside of the rear window or rear side window of the vehicle in close proximity to the filling
location, where it can be observed by the attendant prior to filling. See Figure C.1.
5.13.2
When a vehicle is converted to be fuelled by propane, a permanent label of approved design shall be
affixed on either a door latch or the inside of the glove compartment. See Figure C.1.
5.13.3
A propane-fuelled highway vehicle shall be identified by a weather-resistant diamond-shaped label affixed
to its exterior vertical, or near vertical, lower right rear surface, but not to its bumper. The label shall be
approximately 4-3/4 in (120 mm) wide by 3-1/4 in (83 mm) high. The label marking shall consist of a
border and the word PROPANE* in letters not less than 1 in (25 mm) in height, centred in the diamond, of
silver or white reflective luminous material on a black background.
*The equivalent French wording is “PROPANE”.
5.13.4
The propane fuel system shall be inspected at 5 year intervals, starting with the date of installation, and
re-labelled in accordance with Clause 5.13.1.

[51geezer]

Thank you for the detailed reply, C3H8.

[storm]

I am on the scrounge for the uncommon Q-jet intake manifold, but as finding one is unlikely, I'll probably stick with the Streetmaster.

If you stay with LPG using an OEM Quadrajet manifold will mean you will have to use an adaptor and also fit a Quadrajet baseplate. I love the old Quadrajets and personally believe they are much maligned by people who don't understand them but the IMPCO is a simple design and keeping it simple by using the Holley baseplate without using an extra adaptor like the Quadrajet baseplate requires makes more sense as it removes at least 1 (if not 2) possible extra failure point(s).

[51geezer]

I'd like the Q-jet for the fuel economy, but I don't want an adapter and I doubt I'll ever find one of these:
http://www.supermotors.net/getfile/9411 ... -q-jet.jpg

[storm]

Quadrajets provide fantastic economy because they have small primaries and the jets for the primaries only feed enough fuel for approximately 250 cfm of airflow. They also have metering rods inside the jests to provide cruise economy. Using an IMPCO 425 basically does away with 90% of the design features that make the Quadrajet as economic as it is, all you have left is the small primaries but I would argue that using the adaptor disrupts the airflow to both the primaries and the secondaries meaning you may as well just use a Holley baseplate with 4 small equal sized bores.

Is that manifold the CobraJet intake?

[51geezer]

Nope, not a CJ. That's the uncommon (to say "rare" would imply desirable) U-Haul rental-truck-only Q-jet intake. Some say it is for the spread-bore Motorcraft 4350, but it isn't; the 4350 has a different bolt pattern. The Q-jet FE intake was used circa '73-'80 on the one-ton rentals only. Experts report that the runners and ports are similar to the "T" casting 4V manifold found on many 70's 390 pickups. This black sheep is the only spread-bore intake used on the FE in its lifetime, and perhaps ironically, it was on the lowest-performance example of the breed.
Incidentally, if you have a CJ intake handy, notice how it appears to be cast to accept a spread-bore carb base.
I need a mechanical 4150 throttle body to complete my under-hood parts list.
This weekend going to look at a tank that might be the solution.
Eric