ALKY FC ENGINE HEIGHT AND ANGLE

starting on a new alky funny car 125 inch wheelbase .the chassis is built. now wondering what the normal crank to ground heights used are, and what angle down the engine usually ends up at. thanks for any input. also what does the ground clearance end up at with these measurements.

 

I am in the process of building a 125" altered and my drawing has a crank centerline to ground of around 16" (depends on tire size.). This gives about 4 1/2" to 5" of ground clearance (again tire size). The engine is not angled at all, it sits dead level with the ground.

Corey

 

Pretty sure my current car is about 10.5" front of crank to ground with 34.5" tires....motor is tipped down in front......seems fairly easy to load as far as ground clearance.. I had a car that was very low....around 8" and it was a pain to load in the trailer and it always drug the ground if the pit or return road was rough...the newer cars are being build pretty low....but there are disadvantages....

I think another concern is how far the engine is out....mine is 65" out to the motor plate which is fairly common....

 

9.5 to 10 inches is common to parting face of front main cap.

 

whatever height you end up with in front you must use a bar going thru the mains in the block to line up with the pinon C/L on the housing all have to be inline !!!!!!!

 

When I bought my Jig for 125" F/C style chassis the builder said that they mis-aligned the engine and rear end on purpose....they had run sensors on the drive line and their claim was that when the chassis was under load then the drive shaft was in alignment....but slight interference at rest....it always bothered me so I used the line up bar for the few cars I've built....the couplers and drive shaft always look good so I guess I'm doing it correctly! It's a good idea to put your 32 spline drive shaft in a lathe and check run out - M/W says they shoot for less than .005" when they leave their shop....they do offer straightening service at Mark Williams also...

 

update . found out my mw alignment bar was bent, so that didnt help, and the car has the crank 8 inches off the ground and can barely get my thumb under the bucket. am going to have to make the plates again and realign the rear once more for around 10 inches or so.