Inliners International Forums General Discussion Engines Cheap 250 Mods?

I just picked up a used running 250 from a 1970 Chevy C-10 pickup that is supposed to have some miles but run fine. It passed Phoenix, AZ emissions which isn't the easiest thing to do. This motor is going to be going into a Budget Rockcrawler I am working on. The Crawler will have low gears, big tires, and need good throttle response, idle, and low/midrange power.

Is there any cheap hop up mods I can do to this motor that won't break the bank? I plan to do all the maintanence items, plugs, wires, cap, rotor, water pump, Amsoil Synthetic oil, etc. I will use MSD ignition (wires, 6al box) on this motor because I have had great success with it on my V8 and also my buddies 250 I6.

The motor will get some kind of fuel injection at the minimum so the motor will keep running at heavy angles, but beyond that I am not real sure what mods I can get done with dropping a boat load of cash. I would like to spend under $500 in "performance" mods but want to get the best bang for the buck out of my money. Any help would be great. Thanks

Harley

If it has some miles on it be watchful of the oil. I use a 40 or 50 weight oil because older engines have lower oil pressure because the clearances are not as tight anymore.
I see you plan to use Amsoil Synthetic Oil. I dont know nuthin about that. Just make sure you have an oil gauge since you will be doing Angles and Dangles.
When you get more money... consider an RV type cam for Low RPM Torque. You did not mention what kind of Transmission you're using. If you have an automatic they have Towing style Torque Converters. When you buy a cam it needs to match the requirements of the Torque Converter, Gears and Driving Style.

I am planning on running 20w-50 oil in the motor. The trans will be a TH400 and it will have a low stall converter around 1000 rpm most likely. I have had good results from low RPM converters and low gears.

I have been considering cams. Any suggestions on which cams for lowend & midrange and still computer friendly?

Harley

I saw one Crane Cam rated for 800 rpm to 4200 rpm. It is model number 200511 and is in their Powermax Series. I aint saying thats the best one out there but I was looking for Towing Torque for my work truck. Just check out their website for details on the cam.

Harley:
If you have the facilities to fabricate your own intake, brackets, pulleys, etc, you could put a supercharger from a GM 3800V6 on your 250 for around $500 in materials. Mine has a COMP H268 cam and Edelbrock 600 carb (another $600), but is stock otherwise. It has AWESOME TORQUE! from 1000 to 4000 rpm. The stock EFI would probably work better, especially for your application, but i didn't use it cause i just don't like electronics.

If you are interested, i would be glad to assist with intake drawings, tips, and "don't do's".
Good luck!

How much extra power would Crane 260H cam add for lowend/midrange? I am on the fence about just resealing the motor and running it or adding a cam and resealing it. I doubt I would be able to spend much more money on the motor for awhile. I would like to do an intake and header but I doubt I will have the cash for those for awhile. Is it worth spending the money to do a cam if that is the only thing that will get done beside seal for awhile?

A turbo or super might be in the plans down the road but that is probably a few years off and will be a complete build not a used motor with new seals kinda build.

This is the cam I am thinking about adding. If figure since I a going to do a headgasket in the motor I might do a cam at the same time.

http://www.cranecams.com/?show=browsePar...rtType=camshaft

I agree with you on that 260H because you want some midrange too. I am liking the 200511 because it has a lower RPM band. One thing to consider with an automatic is: Will it Idle OK in Drive with your foot on the Brake?

A Turbocharger usually works better at higher RPMs plus you have to be concerned with intercooler and other temps. Since you plan to play on the Rocks... the less gadgets the better.

How much extra power? I cant say if the cam actually adds that much Horsepower, so much as allows the engine to breathe better at certain RPM. If you get the new cam be sure to get new timing gears. They run about $70

If you want to look at Intakes and Headers here is a link to
http://www.cliffordperformance.net/

Harley, I think either the Comp Cams 252H or 260H cam would work fine for what you want, and if you add a set of headers, the cam will work even better. However, if you add a new cam, be sure to use the recommended valve springs and lifters with it. Wouldn't be a bad idea to install screw-in rocker studs, either, plus a set of posi-locks. Also, there's a real good way to increase your oil pressure for under $10. Go by your friendly local Chevy dealer's parts department and pick up an oil pressure relief valve spring from a 300-325HP high performance small block V8 motor. It'll fit the six cyl oil pump and should give you about 80 pounds oil pressure cold and 50 pounds hot, running 20W-50 oil. I used one in a motor I built in 1975, and it cost 50 cents then. It would probably cost about 5 bucks now, but still pretty inexpensive. And speaking of oil, I can definitely recommend Amsoil. I was on a road racing team that ran 6, 12, and 24-hour endurance races, and we used Amsoil in the race motors and never had an engine failure. It's good stuff. And if the motor doesn't have electronic ignition, replace the points with a Pertronix Ignitor I system. It will work with the MSD box and will be one less thing you have to mess with when you're tuning the engine. Hope all this helps some.

Hey 64NovaWagon... This 300-325HP motor. What year is it? I looked for it and found a 6 Liter LQ4 Vortec Engine. Is that what you are talking about?

pinebluff, those engines were from the 'Vettes and hi-po Impalas, Novas, and Chevelles of the 60's and early 70's, but you should still be able to order one of the springs through a Chevy dealer. Guess I should have been a little more specific.

Thanks for the clarification. My brother in law had an Early Nova with a stock Inline 6 and 3 on the Tree. He would blow away Camaros all the time.

When you guys find the part numberfor the stiffer spring ,could you post it here?
Thanks
MBHD

Don't forget the headers, Hedman P/N 69310

Does Hedman or anybody make a shorty header that isn't $300+ dollars for the 250 I6? For $200 I would buy the Hedman except it is longtube which will be hard to cram into my rockcrawler.

Harley

I thought Clifford has shorty's but I am sure they are not $200.

How about a set of these?
http://www.stoveboltengineco.com/acartpro/
MBHD