1948 P15 Super DeLuxe sedan as LeMons racer

[OnkelUdo]

Depending on your bent, this topic will offend or thrill you.  I just acquired a 1948 P15 sedan basket case that is overall in decent shape but realistically not restorable unless you are a true purist.

 

Short history:

 

Bought for the frame condition by the PO to make a restomod type driver with a busted tranny and some rust issues

Sold it to his brother in law who got another transmission and rebuilt the motor

Sat in a garage for 30 years

 

Now our plan (purist, please leave or risk being offended):

 

We have been racing 24 hours of LeMons for about 4 years and intentional moved to progressively less suitable vehicles for endurance road racing.

 

What our team does...https://www.facebook.com/BadDecisionsRacing

What LeMons is...http://www.24hoursoflemons.com/ ...and it is NOT DEMO DERBY.

 

What we have learned over the years is power is not the key to success.  To drive this point home, our van is 6th slowest of 76 cars (fastest lap) and finished 35th with 2 hours of down time for repairs.  In order of importance:

 

Team coordination and dynamics

Reliability

Brakes

Handling

Racing Stint length

Straight line speed

 

So we plan to run the flathead the first 1-2 races at least.  I actually believe the flat head can easily be good enough but we may need a taller rear end (we learned that the Buick 3800 in our van, coupled with its new manual transmission works best just leaving it in fourth...and it hits 85 mph on the straights pulling many cars in the process). So after repairing minimal floor pan rust and putting the car back together we want to do the following:

 

Front Shock relocation

Disc brake conversion (we put Corvette C5 calipers on the van after melting stock caliper, twice) front

The Moog CC850 springs up front

Appropriate two piston master cylinder (suggestions welcome)

New brake hard lines...from experience in the Midwest just easier

Boil and rod the Radiator

"Clean" the fuel tank with nuts, paint thinner and lots of shaking

New rear shocks (do they need relocation for modern shocks?)

Potentially new rear axle with disc brakes and a higher ratio

 

I currently have no issues with the 6 volt system and for racing, points are OK on the ignition.

 

What I do not know:

 

Best tire size for our 15" rims for max thread width without rolling or rubbing

Better alternate carbs...or run the old one

Method for keeping wheel bearings happy (long story, but very common failure at races)

"Best" rear end ration to cover 45 mph to 80 mph speed range (I know the limitations of the stock motor so the upper end is inspirational)

 

We take the LeMons experience seriously but the racing is just a side benefit.  We are quick for our class but not nut jobs about winning.  The community is amazing and spending time with like-minded folk is a blast.

 

So I would appreciate a LOT of help for phase 1 and when (not if) we go to re-power I will need lots more.  No comment is too insulting  or inane so hit me with it!

[Ulu]

You want me to help you?

Now after watching that video I want to compete with you!

That looks like Tons of fun 8D

[Ulu]

My coupe did 80 to 85 with a 218cid & 3:90 gears on 7:50×15 tires rear, on skinny Ford rims.

Not really supposed to run the Ford rims on a Mopar, but it's all I could find.

The tires did rub a little bit on the inner fender until I clamped up the leaf springs, ran dual rear shocks along with an anti sway bar from a 75 T-bird.

All that really stabilized the rear end, and with soft Springs and radial tires it really handled quite well. I ran KYB high pressure gas charged shocks in front. Four Monroes on the rear axle. I dropped the front end about 2 inches more than whatever it had sagged to, and ran short radial front tires.

My car ran very well & your sedan should as well once you lighten it, because it's quite a bit heavier to begin with.

The stock driveshaft will probably give you fits. I repeatedly trashed mine until I replaced it with a custom-built modern Spicer joint drive shaft. It's gotta have a slip joint in the drive shaft.

Edited May 8, 2016 by Ulu

[OnkelUdo]

You want me to help you?

Now after watching that video I want to compete with you!

That looks like Tons of fun 8D

Not sure which video you watched because there are tons.  Some on facebook and a lot from the LeMons forum.

 

It is a ton of fun and we would welcome you to the team.  Because of how we run the team, we have spun off one driver who has started his own team and we always have more potential drivers than one car can handle...so we are thinking of running two cars (this P15 and the Dustbuster van) for a race or two in 2017.

 

So my most immediate need is the best modern tire size for those stock 15" rims.  I made a 70 mile car dolly tow on the 30+ year old bias ply tires and do not want to do the 20 miles relocation to its final home without replacing the rears.  I expect my normal used tire places to have nothing in these relatively narrow sizes so having to buy new.

[OnkelUdo]

My coupe did 80 to 85 with a 218cid & 3:90 gears on 7:50×15 tires rear, on skinny Ford rims.

Not really supposed to run the Ford rims on a Mopar, but it's all I could find.

The tires did rub a little bit on the inner fender until I clamped up the leaf springs, ran dual rear shocks along with an anti sway bar from a 75 T-bird.

All that really stabilized the rear end, and with soft Springs and radial tires it really handled quite well. I ran KYB high pressure gas charged shocks in front. Four Monroes on the rear axle. I dropped the front end about 2 inches more than whatever it had sagged to, and ran short radial front tires.

My car ran very well & your sedan should as well once you lighten it, because it's quite a bit heavier to begin with.

The stock driveshaft will probably give you fits. I repeatedly trashed mine until I replaced it with a custom-built modern Spicer joint drive shaft. It's gotta have a slip joint in the drive shaft.

So realistically it sounds like an Explorer 3.55 rear would be fine and a 3.27 might be too tall but might be perfect. 

 

I am thinking once we have the front sorted the rear might involve loosing a leaf or two and/or redneck coil-overs but we will find a swaybar somewhere...the one on the van came out of  Cadillac STS so anything could be a donor.

 

Once ready to race the car will have no interior except what is required to keep the wipers working and the defrost working...so if anyone is interest a near pristine but dirty stock interior it will be up sale to the lowest bidder.  That said, the adding of the roll cage and other safety equipment tends to include about  250-300#'s so the only real net weight savings is likely removing the side glass.

[greg g]

Mid 60's A body rear shocks will fit, then you can get gas shocks or even adjustables if they are permitted.  I would run 205 75 X 15 tires they are a bit short but should not rub fenders.  Some Plymouths had rear anti roll bars, and a panhard rod ( track bar) could be added.  You might wan to give George Ashe a call and see if he has any long 2nd gear sets available for the trans. Makes 2nd good for 55/60 instead of 45.  A Satellite, charger, Coronet rear end will give you better rear gears and more easily servicable rear brakes.  Are Drilling brake shoes allowed?  This was a trick use by dirt track racers before disc brakes.  the drums are drilled through the friction contact area in a diagonal pattern of small holes.  This lets friction gasses out, for better shoe contact and increases cooling to deter fading. (http://www.chtopping.com/CustomRod4/)  

 

I believe Ford used a Holley carburetor for their 200 cubic inch 6 that has externally replaceable/ tuneable jets, that should bolt on. AMC used a similar on on their late car and jeep 6 cylinders. Are carbs optional?  Maybe look at an SU side draft 1 3/4 or 1 7/8 buterfly.  These also allow you to tune the main jet externally. You would need to make an adapter but that could be done with some exhaust bends and flange welding.

 

Front sway bar can be replaced with jeep cherokee stuff. Jeep Cherokee could also be a source for rear end with disc brakes (also ford explorer and ranger)

Edited May 8, 2016 by greg g

[greg g]

Don't know if you have seen this one.  Set up for One Lap of America with Crovette stuff.  Just for visualinspiration.

 

http://img.photobucket.com/albums/1003/tinkerbb/HOTRODPRIMER/odds%20and%20ends/112_2009_one_lap_02z1948_plymouth_c.jpg

[OnkelUdo]

Mid 60's A body rear shocks will fit, then you can get gas shocks or even adjustables if they are permitted.  I would run 205 75 X 15 tires they are a bit short but should not rub fenders.  Some Plymouths had rear anti roll bars, and a panhard rod ( track bar) could be added.  You might wan to give George Ashe a call and see if he has any long 2nd gear sets available for the trans. Makes 2nd good for 55/60 instead of 45.  A Satellite, charger, Coronet rear end will give you better rear gears and more easily servicable rear brakes.  Are Drilling brake shoes allowed?  This was a trick use by dirt track racers before disc brakes.  the drums are drilled through the friction contact area in a diagonal pattern of small holes.  This lets friction gasses out, for better shoe contact and increases cooling to deter fading. (http://www.chtopping.com/CustomRod4/)  

 

I believe Ford used a Holley carburetor for their 200 cubic inch 6 that has externally replaceable/ tuneable jets, that should bolt on. AMC used a similar on on their late car and jeep 6 cylinders. Are carbs optional?  Maybe look at an SU side draft 1 3/4 or 1 7/8 buterfly.  These also allow you to tune the main jet externally. You would need to make an adapter but that could be done with some exhaust bends and flange welding.

 

Front sway bar can be replaced with jeep cherokee stuff. Jeep Cherokee could also be a source for rear end with disc brakes (also ford explorer and ranger)

FYI, this is not vintage or stock or SCCA type racing.  Creativity is encouraged!  If it it Safety related it is budget exempt (includes brakes and a few suspension items) while if it is performance related, it is the easiest way to get penalty laps if you exceed the $500 car value...even that is flexible since we are bringing a post-war flat head.

 

So we will be doing front disc and suspension lowering.  We will likely be doing an axle swap with high gears and disc brakes.

 

I like the Jeep Cherokee idea for rear end as they are almost as plentiful as explorers in the PnP.

 

The 2nd gear swap intrigues me.  As mentioned as long as we are on the track, we will likely be over 40-45 mph all the time.  The second, not broken, tranny that came with the car has a spedo drive in a different pace so I may have figure out what it came from...we can then play with the "broken" transmission for gearing upgrades.

 

Carb swap sounds like a good idea with the externally swapable jets.  So look for a vintage Holley from an early Ford flathead of late AMC OHV 6?

Edited May 8, 2016 by OnkelUdo

[greg g]

The holley I was talking about were used on the bigger Ford 6's the OHV deals fromthe 50's to the late 60's used in full sized cars, and light trucks not the flacons fairlanes etc.

 

 http://www.fordification.com/tech/images/schematics/carb-ford-1bbl.jpg

 

Forgot to mention dual M/C.  My Studebaker truck has one from a Jeep attached to  the frame in a similar position to where the stock one was.  It has been suggested here that the new MC for a P 15 be mounted behind the stock one so as to retain the mounting system for the brake pedal.  The stock one has its bottom portion gutted and an extended actuator rod is fabricated that runs through the bottom of the stock MC to operate the dual res one mounted to the rear of the stock one.

 

Where do you do your racing???

Edited May 8, 2016 by greg g

[OnkelUdo]

Where do you do your racing???

Our primary tracks (three races a year) are in Joliet, IL and South Haven, MI.  We are making a hard run at a class C victory at the July Joliet and the October South Haven races with Trans Sport.  We have a good shot is we do not have another unforeseen GM penny-pinching failure.

 

The other car owner and I are doing one "destination" race a year at bucket list tracks along with any team mates that are willing/able to come.  This Year was Barber Motorsports Park which is amazing!  2017 is up in the air but we will likely take the more well sorted, fully debugged van to wherever is (likely Carolina Motor Sport Park) because on top of the normal expense of racing there it loss of two additional days of work, towing fuel, etc.

 

The P15 is likely to debut at the Late April 2017 race at Gingerman Raceway in South Haven, Mi.

Edited May 8, 2016 by OnkelUdo

[Ulu]

Okay clearly I don't get the $500 thing. Your barely going to get new tires and a battery for $500.

How exactly does the financial stuff work?

[OnkelUdo]

Okay clearly I don't get the $500 thing. Your barely going to get new tires and a battery for $500.

How exactly does the financial stuff work?

It is simple in concept but gets confusing the more it is explained so I will give you the really short version and then the alternative version:

 

$500 is the car less all the parts you sold off it plus any non-safety improvements.  So If I buy a $970 P15 and sell of $900 in interior and trim then add $400 in suspension items it is $470.

 

Safety items include anything you want the OTHER cars to have that are running 3-wide through a turn with you at 60 mph plus everything required to keep insurance down.  Examples:

 

6-point cage

Racing seat

5-point harness

Brakes

Wheels

Tires

Ball joints and tie-rod ends

Hubs and wheel bearings

Windshield

Exhaust aft of the header

Fuel system before the injectors/carb

 

Now the real method of valuation if you bring a 68-year-old family sedan with an 85 hp flathead 6 motor...nobody cares!  They will just be tickled and I will have a really good chance at the highest prize if we keep it running the whole race.  I honestly think we could put a pretty sophisticated suspension under there and they still would not care but we do try to keep it in the spirit of budget racing (partially because its cheaper and partially because it is more fun) where we bodge everything together from junkyard or off-the-shelf parts.

Edited May 9, 2016 by OnkelUdo

[OnkelUdo]

Did forget to ask one important question, will stock wheels work with tubeless tires or do I need to run radial tubes until we upgrade them?

[greg g]

Stock rims will work tubless, but you need to look out for the valve holes.  Some of the rims have an oval hole so you need to use the two piece screw together style valves to cover the hole.  They are a bit narrow for todays tires.  You might want to check out other 5X5 lug pattern wheels that are 5 to 6 inches wide, but you need to watch the back spacing as there is not much room between tire and springs.  If I remember correctly 3 3/4 to 4 inches is max.

[_shel_ny]

89 Dakota wheels with 235/15's already mounted and balanced gave me some solid footing on the rear of my 48 Dodge.  Spacers were needed to keep the rub off the inboard side due to the back spacing issue that Greg mentioned. .

[OnkelUdo]

Stock rims will work tubless, but you need to look out for the valve holes.  Some of the rims have an oval hole so you need to use the two piece screw together style valves to cover the hole.  They are a bit narrow for todays tires.  You might want to check out other 5X5 lug pattern wheels that are 5 to 6 inches wide, but you need to watch the back spacing as there is not much room between tire and springs.  If I remember correctly 3 3/4 to 4 inches is max.

Once we land on the brakes and suspension upgrades, we plan to check out other options for wheels.  We had the same issue to lesser extent on the van when we had to upgrade to 17" wheels for the (almost too large) upgraded brakes.  Only one vehicle ever manufactured had the correct lug pattern, backspace and wheel diameter...and then only in the top trim level with the optional wheel package!

 

For now, I just need reliable rollers that can later works a fair weather street tires on a limited basis.  For the first race we do plan to at least have disc front plus some lowering but there will be some discussion about a rear axle swap or not once we street drive it...my guess is we will be doing one but it seems a shame to do whatever custom drive shaft work needed for a non-stock axle when we know we will be re-powering it at some point.

[greg g]

well you can get to a gear ratio/tire diameter calculator online, (there is one at 4 lo.com that works well) you can run some predictions on speed Vs rpms.  These flatheads are long stroke torque makers and are pretty much done at 4000 rpm.  Factory HP rating was taken at 3600.  The factory used to pull engines off the line for testing.  They hooked them to a dyno to simulate road loading conditions, and ran them at 3600 for 24 hours. 3600 works out to around 65 mph with the gearing of the day, so the test run was the equivelent of 1550miles or so.  The concern here is piston travel friction loss and crankshaft oiling at extended high rpm.  This could be especially critical in endurance situations. Also if you get any connecting rod stretch and bearing slop, rings may contact cylinder top ridges breaking them.  This is a fairly common occurance in high mile engines.  So you might want to pull the head and check out the condition of things as they exist.

 

You may also want to contact member Tim Kingsbury through his blog or a PM and ask him if he might have any tips for building a reliable motor for your purposes.

[OnkelUdo]

Excellent information!  I figured the HP peak was about 3500 so good to have confirmation.

 

I will play with the ratio calculator tonight.  We will likely be running considerably smaller diameter tires hence the reason I am almost sure we need to raise the rear ratio.  The goal would be 60-70 mph by the end of the longer straight but I find that a "stretch" goal...60 might be attainable.

 

As I mentioned in the first post, keeping it on the track (reliability and stint length) matter much more than lap times plus we doubt we will ever be in contention for a class win without some additional power or insane stint lengths (unobtainable with a stock fuel tank).

 

We do intend to tear down the "fresh" rebuild as it has sat for 30 years.  Hoping to find the hard parts and bearing well preserved but feel it wise to do all seals and gaskets.  Nothing ruins a fun race weekend like an oil leak that get's you black flagged until you fix it...except through a rod through a block.

[greg g]

Rear main seal leaks are a part of the pedigree of this breed. Early engines were rope later neoprene, neoprene is marginally better than rope.  Also do not over tighten the fasteners holding the valve gallery covers.  They deform easily and will never seal well after thay get out of shape.  number three is the gasket between the trans and the belhousing.  The holes in the case that  shafts the gears slide on are open and leak a lot if the gasket isn't  there.  Trans wants G L 1 lube, modern stuff is not good for synchro brass and bronze pieces.  I have had my 230 up to indicated 75 for short bursts without problems.  My rear end is 4.1 to1, I run 225 75 rear tires in 15 inch wheels.  3280 rpm is 62 mph via GPS, 65 on the speedo.  I run all day at that speed.  Have had the car on many long trips with no drama except for a thrown fan belt.  (speaking of which, check the condition of your vibration damper, they like to delaminate with age causing driveline vibration and possible catastrophic failure.

[OnkelUdo]

well you can get to a gear ratio/tire diameter calculator online, (there is one at 4 lo.com that works well) you can run some predictions on speed Vs rpms.  These flatheads are long stroke torque makers and are pretty much done at 4000 rpm.  Factory HP rating was taken at 3600.  

Found a calculator I can use at work and it is looking like the 3.55 out of an Explorer is theoretically perfect.  70 mph at 3600 RPM with our intended race tire size.

[Ulu]

I didn't see if you had a 230 or 218 engine, but there is a lot of difference from that 1/4" stroke.

 

Noticeably more torque on the 230, but the 218 winds up faster.

[OnkelUdo]

I didn't see if you had a 230 or 218 engine, but there is a lot of difference from that 1/4" stroke.

 

Noticeably more torque on the 230, but the 218 winds up faster.

My assumption is stock so that would be 218, right?  It was rebuilt and I have the former pistons as part of the deal if that would give a clue.  Motor itself is currently shrink wrapped in the back of my truck until I can relocate the whole mess to our secret work shop deep in the South Suburbs.

 

Neighbors are getting a kick out of it.

 

Edit, I see the difference was stroke so piston diameter won't help.

Edited May 10, 2016 by OnkelUdo

[Ulu]

Could be either if someone had stuck a Dodge engine in it, or a Dodge crank in the 218 to make it a 230. This was pretty commonly done.

 

You pull the 1/8" pipe plug out of the head over the #6 cylinder and put a rod in to the piston top as a depth gage, then turn the engine & do it again. The difference will tell you the stroke.

[greg g]

I always thought 218's spun up faster cuz they were not trying to spin up a fluid drive, at least with Plymouths.

[OnkelUdo]

So me and the co-owner are starting to put together a build plan and the topic of the front disc brake upgrade came up.  The easy answer is the Rustyhope kit but there is the very real fear this might meet our needs.  If, as suspected, this kit uses the GM A-body calipers they are the SMALLER version of the calipers that we literally turned the pistons into molten metal TWICE at two different races on the van.  The van is likely a couple hundred pounds heavier that the P15 will be but this failure was not an issue of pad compound, etc it was issue of the inherently flawed (for endurance racing...not street driving) design of the caliper.

 

We saw the Scarebird setup but if I am reading things right, same issue as it uses Celebrity calipers.

 

So, has anyone tried using a different setup?  We home brewed the Corvette C5 conversion on the van using 3/8" plate and lots of frustration but that was on relatively modern 3-bolt integrated hubs.  I am sure we can figure things out if we are in uncharted territory but just wondering if there is someone that did either a multi-piston brake of at least one where the whole diameter of the piston contacts the back of the pad.

 

Emphasis is also on chain store availability of replacement parts...in stock...on a Sunday.  This part is sadly more important than it should be.