Chassis Plans

Frequently Asked Questions

I am going to try and lump all the information that pertains to all of the chassis plans I offer in one spot. Some of this will be a repeat of what is on the chassis plans page. there are also nearly a hundred build up pages that cover everything I did and purchased over the course of my builds. Please read them over before e-mailing questions.

    Question - What is included in the chassis plans?

    Answer - Hardcopy prints on 11 x 17 paper that details the required tubes to build the base chassis including cut lengths, bend start points and angles. All the plans are broken into stages, the first being the lower section and moving up from there.  This video should give you a good idea of what you get.  It covers what is included in the second stage of the Project Hellraiser Pickup chassis and includes the bending and mocking up of the belt line tubes from the plans.  The plans basically give you an envelope that can hold a drive train and passenger compartment. They are is easily customizable to make changes to the size of the chassis or just to add you own style to the final outcome. I do not provide suspension mount points due to the sheer numbers of ways of doing it, however you can copy exactly what I have if you desire using the 4 ink numbers I provide with the plans. For more information please look thru the above builds as well as the suspension links listed below.

 Question - Do the plans also detail the suspension mounting points?

    Answer - Yes. From 2015 on I will be adding a page to the chassis plans set which shows you how to fill in the 4BarLink calculator** and gives the suspension mounting points I used for my Hellraiser 3 chassis.  Previous purchasers of my plans can download a PDF of this file from the electronic files link I sent you after you purchased the plans (see below for an image of what it looks like). The mounting points given can be used with any of my chassis designs or can be used as a starting point. You may also read thru my project build threads and in my tech section I have write ups covering the basics to a link suspension, suspension links, and 4 link numbers.  The 4 link numbers link discusses some of the 4 link numbers used by others and how their vehicles performed.

** Written by Dan Barcroft and Greg Blanchette

     Question - I don't use PayPal, how can I use my credit/debit card to pay?

    Answer - You still use the shopping cart buttons but when the PayPal checkout screen appears click on the underlined "continue" in the lower left corner of the screen where it says:

    Question - How much tubing is required?

    Answer - For costing purposes I used approximately 8 sticks of 1.625 x .120 DOM, and 2 sticks of the following: 1.50 x .095 and 1.50 x .120 for the main chassis bracing. To save money you can get away with using HREW for any piece of tubing that does not contact rocks.   

  Question - Can I use a different diameter tubing or bender die?

    Answer - Yes, 1.5" OD or 1.75" OD tubing can be substituted for the 1.625 OD the plans call for. The difference in tubing diameters makes almost no difference in the bent tubes and can be easily compensated for in the straight cut tubes (lengthen or shorten by .125"). Honestly between the chop saw cuts and coping the +/- .125" can be ignored, which is what I did when I fabricated my last Hellraiser 3 chassis with 1.5" OD tubing.  I made no corrections from the plans.

I used a 4.5" bend radius tubing die when I built my first chassis but those size dies are no longer readily available.  A 5.5" bend radii seems to be the most common die set out there now and only minor changes need to be made to compensate for the larger bend radius.  Using a 90 degree bend as the baseline, the bend start point shown on the plans needs to be started 1" sooner with the a 5.5" radius die. This scales with die size so a 6.5" bend radius die needs the bend start points to start 2" sooner.  For angles less than 90 degrees, scale the  bend start point correction factor with the angle, so for example: if the plans call for an angle of 45 degrees (half of 90 degrees) the 1" correction factor becomes .50".  I put together a model that overlays a tube from the plans, the yellow is the 4.5" bend radius die and the blue is a 5.5" bend radius die.  If the 90 degree bend is started 1" sooner and the 60 degree bend is started .66" sooner the finished tube will match the plans.

The cut lengths are affected slightly but if you are adding a couple inches (like you should be) you do not need to adjust.  In the above example the 90 degree bend side requires another 4" of tubing in order for me to lock the end of the tube into the u-clamp on my JD2 bender and I cut the end to length after both bends are installed.

    Question - What are the differences in the chassis plans?

    Answer - The sub-chassis on all my designs is very similar with only minor changes.

 BMP 3, BMP 2 and Hellraiser 4 were all designed with a front mounted radiator in mind. Structurally the A & B pillars are offset from the outer tubing on the lower chassis to create a nerf bar. BMP 2 has the longest nose of the 3 to accommodate longer drive trains. It is very easy to make adjustments to any of these 3 chassis's and I point out where you can make changes on the blueprints.

The Hellraiser 2 Pickup, Buggy and Hellraiser 3 chassis's were all designed around a rear mounted radiator so if you look thru my HR3 buildup thread it should be pretty easy to see how you get better visibility and a sleeker front end over my previous designs.  The trade off is more complex plumbing and heat management with the radiator out back. These 3 chassis designs also have the A & B pillars flush with the lower chassis which gives you roughly 3 more inches of width in the passenger compartment over my first 3 designs.

The bottom line is you could make the changes yourself to convert any set of my plans to the others without too much difficulty or you can pick one closer to what you want and make minor tweaks from there.

    Question - How much time is required to build a turnkey rock crawler from your plans?

    Answer - It took me over 615 hours of constant work (every weekend and after work) over the course of 4 months.

    Question - How much does it cost to build a crawler?

    Answer - Material prices vary by region so you will need to get a quote for the amount of tubing listed above.  I did a complete budget of my original build here which includes all the little stuff I bought. Some of that information is a bit dated so I have started another costing page as I build up my Project Hellraiser 2 chassis.

    Question - Can I buy a pre-built chassis from you?

    Answer - I do not build chassis's to keep some in stock.  In fact up until now I have not done any fabrication work outside of my rig mainly due to time constraints.  I may consider building a bare chassis, contact me for more details at 


Ford 4.6L Vs 302 V8

    Question - What drive trains fit?

    Answer - Pretty much anything can be made to fit.  4 cylinders are no problem and most 60 degree V6's are actually more compact than a lot of the inline 4's currently out there (Suzuki 1.3/1.6, Toyota 2.4/2.7l, etc).  About the only engines that would give me pause are 90 degree V8's like a Ford 5.4L or 4.6L since they are so darn wide (see picture above). That said It is easy to make adjustments to the chassis so if you did have a blown 5.4L and wanted it in the chassis you could as long as you were willing to put up with a wider front end.  The Chevy V8's (250, LT1, LSx) are an easy fit. Inline 6's present another problem - length.  You'd have to stretch the nose of each chassis a few inches (assuming a front mounted radiator) except for the BMP 2 seater which was designed with a Jeep 4.0l drive train in mind.

LS1 shown

If you go with a rear mounted radiator you should be able to fit just about anything.

Short Block Chevy w/ TH350 Shown in the Hellraiser 2 Seater Chassis (Buggy or Pickup version)

For reference my 3.8L/904/D300 is roughly 54" long (pulleys to rear output), 28" Tall (oil pan to top of motor) and 22" wide at the valve covers.

6.0l LS2 and Atlas Shown

Here's a link to customer's Facebook page, he installed a Chevy 8.1l into his chassis.

    Question - What wheelbase can I run with this chassis?

Hellraiser 2 Chassis with 100" Wheelbase and 37" Tires

    Answer - Your wheelbase will be determined by your drive train.  For example any motor in front of a Toyota 5 speed with dual transfer cases will be at least 12 inches longer than my current V6/Auto/Dana 300 combo.  Pretty much any chassis with an automatic and a single transfer case behind a "V" motor could run a 100-112+" wheelbase. The dual transfer cases behind a 5 speed make for a long drive train and could push the wheelbase from 105" and up depending on how far forward you push the motor and what kind of rear driveshaft you are running.  The best thing to do is mock up your drive train and drive shafts and see what sort of angles you end up with. For reference when I had my inline 4/Toyota 5 speed/dual Toy cases I had a 29-34" long rear CV driveshaft, 10.

                One other thing to keep in mind with wheelbases under 105" is that the chassis will have to sit higher to allow for adequate clearance between the front axle and engine.  This added height can be offset with smaller tires.

    Question - How much does chassis "X" weigh?

    Answer - That depends a lot on what you install into the chassis but I can provide a few references:

    3 Seater with Suzuki 1.6/Toyota 5 Speed/Dual Toyota Cases, Toyota axles, 37's, steel bead locks - 2800lbs.  This was about 100lbs lighter than my tubed out Suzuki Samurai with a single 8:1 transfer case.

    3 Seater with S/C 3.8l V6/TF904/Dana 300, D60 Front & Rear, 14 Bolt Rear, 42" tires, aluminum bead locks - 3800lbs    (motor is about 450lbs)


4 Seater with S/C 3.8l V6/TF904/Dana 300, D60 Front, 14 Bolt Rear, 40" tires, aluminum bead locks, aluminum links - 3844lbs

    The bare chassis weight is anywhere from 250-350lbs depending on the bracing, material thicknesses, etc.

    Question - What kind of tools will I need.

    Answer - Check out the chassis fabrication write up here.