Need for Speed

[Michaeb5353]

Forgive the corny title,

I own a fj40 1975 Cruiser with a chevy 1991 350 smallblock. I have 31.5 inch tires new suspension and carb.

Right now my comfortable max speed is around 50-55, anything more things start shaking, and the engine sounds like a constipated moose ( high RPMS ). I'd like to be able to cruise at 60-70 without hassles.

What would give me the best bang for my hard earned money? I am able to spend around $1000 all things included. I dont have access to tools or much technical expertise. But I'd like to learn.

Would getting larger tires make quite a difference? Any other suggestions?

One other question, what is the best way to learn how to do your own automotive work? I am sick of massive labor bills. Should I take a class? I am afraid to just dig in as the cruiser is my daily driver to school, and I can't afford to ruin something.

Thanks a ton.

 

[trainrech]

You want to do 80 mph in a 29 year old 40?

Yipes!!

 

[Rice]

There isn't a lot of description to go on here but I'm going to guess the shakes and the "constipated moose" are not related.

Start by tell us about the shakes ... are you talking about "death wobble" or vibrations or what? If the steering in your rig is stock then you have a lot of pivot joints that will wear and cause steering wobble. Vibrations can be coming from tires, U-joints, pinion bearings and more.

Bigger tires are cheapest but I can't say the best way to go faster. Raising the center of gravity on a cruiser is an easy way to park it on the lid when doing 60 MPH.

If you really wanna go faster find someone with a later model cruiser who has 3.70 rears and will trade you for your 4.10's.

Rice

 

[Jetboy]

I owned a cj for a while (i'm a little embarassed) and I also wanted a little more top end speed. I put 33's on it and checked the speed with a gps. at 60mph on the speedo I was a little over 70mph. you could also figure it out the math its not terribly complex, but it was a big change in mileage to keep the I6 in the jeep at a resonable rpm on the highway. this would be a cheep option, and a little better in the hills, but I would figure out the wobble first.
Also I'm not sure what type of school you go to but where I went to H.S. we had a ASE certified auto training shop, in fact you could log hours for your certs and have five of the certifications before graduating from high school. anyway school shops and beginner classes are usualy good places to get started. many universities are also connected with a tech school and will allow you to take some credits at the tech school.

 

[fj40charles]

I would not think the vibrations would be caused by the engine. I look at the driveshaft and make sure the ujoints are in phase. Also, are the tires balanced?

 

[Michaeb5353]

Thanks for the advice and help.

I think the shaking is because of the tires balance. I drove it over 1500 miles when I first purchased it without any shaking. It has been a new development after adding new tires+suspension.


The constipated moose sound I imagine is just the RPM's I believe, the rest of the cruiser seems to be in good shape.

Rice, how difficult is it to change out the rears? That is an interesting option.

What is a reasonable price to pay for 4 new 33's with installation? I've been quoted $140-160, am I getting ripped?

 

[Mace]

Get the TRE's checked out and do an allingment on it.

Also ceck for loose bolts in your suspension system.

Best place to learn about working on your vehicle. Go get a chiltons manual and use it to tighten everything that you have had someone else work on..

 

[Ponce]

Where do you live? I've learned by just diving in. When I get in over my head I get on forums like this and call on LC buddies I've made through the years. Look for a local club in your area. LC owners are usually more than happpy to talk cruisers.

 

[Isotel]

I run 35" tires with my small block at 80 down the road every day to school and back..

But mine is a 76 so its only 28 years old =)

Spring it over and put 35's on it.... Id bet you can hit 110!!!
(Dont try this at home, Joking, Me not liable for damage inflicted)

 

[Michaeb5353]

Haha, good call with the 35's, and I think I might just dive in.

What would it cost to spring it up? Just looking for a range?

The RPM tables I found a link to on this forum really proved that tires don't make that much of a difference. I guess I'll have to change my rear-ends. Still, getting 35's on there would be awesome.

 

[Rice]

If you have done suspension work and the vibration came as a result I would suspect either the rear driveshaft is out of phase or that your U-joints are worn or not operating at matched angles. Take a careful look at Tom Wood's web site and read up on driveshaft angles ... you may find this is what's happening:

http://www.4xshaft.com/

Look at the "geometry 101" section and see if this applies to you.

The rears take about 1 hour to change the rear and 3 hours to change the front. A job that takes no special tools but that you wish to do with good instructions or someone looking over your shoulder.

Rice

 

[Isotel]

My spring over and Power steering ran me about $800.. $200 for Hysteer arms, $140 for Tie rod ends, $100 for Tubing and having them taped, and stuff machined for the Tie rod ends.. Shocks $100 or so.. Spring Perches $30 Its all the little stuff that adds up..
Junk yard for all the PS stuff $100 $100 for the U-joints for PS.. You need a welder and minor fab skills.. Look in the tech section..

Or just put 4 inch lift springs on it for under $500