My Questions, Ideas, and Ramblings About a High(er) Powered 350.

Dan, I asked about an MSD or HEI ignition system back in September on someone else's thread and if I remember right I was basically told to just keep the stock setup I have because an upgraded ignition system won't do squat for a stock 350?

And the net horsepower of a 72 350 was like 260?

 

That piece is a vacuum / electrical idle advance of some sort. My '71 had all that originally. Vac. hoses went to air cleaner snorkle, which had a vac. motor valve for the air inlet 'doors' on the ram air cleaner. Elect. wires went to some idle advance sensor that I've got rid of. It's designed to close the air doors to speed up warming the eng. in cold weather. Still have the parts hiding somewhere. No performance gains at all.

 

Correct with the HEI. I have it on mine, but it came that way when I bought it. I like it, no hassles at all. Any performance increase? Marginal if anything at all.

With the heads, there are no aftermarket heads available for the 350. None available in the foreseeable future.

Doing engine work is all about the combination. You can port the heads and see some benefits, but unless you consider intake, headers, cam, exhaust - you won't see the full potential. Mull things over for a while, get a good combination together that fits your budget, and get at her.

My suggestion, you want to have a fairly stout engine by the sounds of it so be prepared to pay. Do anything you are comfortable with yourself, leave the complicated stuff to the professionals (head work, etc).

Cheaper power

-get some headers and probably a 2.5" exhaust. Unless you plan to go bigger on power, 2.5" is large enough.

-pick a cam to match your plans, a TA212 is probably a decent choice. It really depends how far you go into porting the heads, and what compression you decide on. Don't forget valve springs, get a set to match whichever cam you settle on.

If you have money to burn...

-get the heads ported, port and port match your intake to the heads, get a valve job, and mill the heads slightly to get a little bump in compression. You can look at getting the exhaust crossover blocked in the heads too. Depends if you do any cold weather driving. You could think of putting in the larger valves too if you want to spend the money. $1000-$1500

-have a machine shop look over your short block while you're getting your heads done (likely at the same machine shop). See if it needs any work. If it looks alright, freshen up the seals (rear main) and put in new cam bearings. If it does need work, you can take the opportunity to pick a hi-comp piston if that fits your plans. Going N/A? Get the higher comp ones. Think of throwing NOS or a turbo on at some point? Stick with lower comp. $???

Doing this will put you well over your 300hp goal. Put a good gear in the back end (3.08 - 3.42) and enjoy. A better than stock torque converter could be usefull too, 2000-2500 stall or so. If your tranny is solid, I'd leave it alone. I've got a shift improver in my car, and don't notice it at all. Starting to think the mechanic messed something up.

All it takes is money.... don't forget all of the engine oil, coolant, tranny fluid, break in additives, cam lube, themostat if needed, gasket kit...

 

Matt what kind of budget are you looking at? Buicks can be expensive the more power you wan to make. Personally I'd freshen up the motor if you think it might need it. It's always best to start with new seals and gaskets. Have you checked your comp? Might just need new rings if you are losing comp.

Other than that, you would be suprised what a high stal converter, lower gears (numerically higher), and a posi unit would do for your accelleration.

If you want higher comp you have a few choices. One is to get pistons rated for higher comp ratio. You raise your comp ratio by decreasing the space in your cylinder and your head. Second choice is to mill the block so shorten the deck and reduce the volume space. Third and this is probably your best bet, mill the head if you are going to have porting done on them anyway.

You sound kind of new to motor build ups so the only other thing I'll tell you is that dont believe HP gain numbers thrown out in catalogs. You'll see numbers like "up to a 20hp gain" on a cat-back exhaust. The UP TO plays a big part in the ad. I have built up many cars, and after you actually dyno them you might gain 6-8 RWHP. The only way you are going to see a 20 HP gain is if you have an absolute HIGH PERFORMANCE motor, ported aluminum heads with big valves, big cam, timing adjustment, headers, cat removal, and super/turbo charger. You will never gain the maximum hp claim on a stock motor. Thats why they say "up to", could be no gain, 3-6, UP TO 20.

 

Seeing all these build up threads wants me to finish the truck project so bad..

 

One thing to remember is that you are not going to bolt on 50 plus hp for $100 or less. Unless you want to make a grenade with nitrous. My recomendations are budget minded.

I assume you allready have a 4brl motor, if not go with a stock intake, other than weight there is not alot of difference in performance as far as flow characteristics. Stick with a quadrajet and learn how to tune it. You will get better gas mileage and reliablity with one.

Next upgrade to a stock hei or aftermaket ingintion. Mostly for reliability. Stock hei can be picked up fairly reasonable. Make sure it is wired in properly. YOu have to replace the coil resistor wire back to the fire wall, pretty simple.

I would go to the rear end next, 3:42 gears will feel like nitrous if are use to a 2;56 peg leg. If you cannot find a complete rear then us a 71 or 72 8.5 case, the gears and parts are much cheaper. There is some people here on the board that specialize in setting up rears.

Headers could be next, but if you allready have 2.5 in exhaust in good condition I would move onto something else. Too much exhaust can hurt your combintion too. A good 2.5 system with good mufflers and without an X or crossover pipe will easily handle 300 hp.

A Transmission service with a shift kit installed along with a small converter goes a long way too. After the gears are installed 400-600 rpm over stock will still be very streetable.

Then, maybe get into the motor with a cam swap. If you motor is relieable and runs smooth now leave it alone for now.

 

Craig, there's a chance that I may ad a turbo a few years down the road. And I've realized in the past few days that going to high comp is pretty expensive. So it looks like I'm staying with low comp.

Nick I've got a two year summer budget of about $3000. I know there's no way I can do all of these things with that kind of budget but I want to see what I can do with it.

 

Alright, So now I'm thinking posi with gears... Tell me about how much am I looking at for a swap? And what's needed to do this?

 

http://www.v8buick.com/showthread.php?t=195587

Devon

 

You won't know if you need to overbore until you get the block checked. And if you do, it's pretty much the same cost to go high or low comp.

 

Thanks Devon. It seems like I always start a thread or ask a question then someone gives me a link to it from a week before. And I always try to search to see if there's a thread already that can answer my questions. Maybe I'm just blind? o No: haha

Oh and what kind of fuel mileage am I looking at with a 3.42 posi?

 

I got a posi unit for 125 from wheelz here on the board and I got the yukon gears from monzaz on the board I think he charged me 90ish for the gears.I did the install myself but setting up gears can be a pain unless you know what you are doing and have all the tools I know shops around here charge 1k to install them..

 

How'd the install go? Time wise, and difficulty wise?

 

If you find a machine shop that can mill the heads, figure out how much needs to come of to bump your compression to what you'd like it to be and have them mill the heads, shouldn't cost more than a couple hundred bucks, cheaper than new pistons. If your adventurous, look up a how to port heads yourself article and get a die grinder and bits and just smooth the ports out yourself and port match them to the intake. If your worried about going into water (which would require you to start to take a lot of material out) just do what you feel is good. I can try to take some really nice pics of my heads so you can see what you have to work with. Doing i yourself could save a ton of money. And for an ignition upgrade, just get a Pertronix unit and their coil. You have exhaust so the big ticket hp makers are headers, porting, bumping up the compression and getting a cam to take advantage of it and an intake. Tuning the carb would be a smart thing to do too

 

Thanks Mike. I've been reading porting articles for about 3 months now. I was wondering if it was realistic to possibly do it myself, but I guess with a lot of reading and talking to you guys it is possible.

 

Pick up a copy of this book off of ebay, from their website, or likely from Amazon...

http://cgi.ebay.com/ebaymotors/ws/e...kparms=algo=SI&its=I%2BC&itu=UCI&otn=10&ps=63

It goes through the porting process and will give you alot of great information for the entire engine... its a must read imo.

 

I think most of you guys know what I'll say about this one. :Brow:

 

Please. No more. ray:

Devon

 

Too funny Devon! :laugh: :laugh: :laugh:

 

Ive had to comtemplate if i wanted to mill my block/heads to get high compression or to get new pistons. You can get a set of hyper pistons and rings for like 220 http://www.fastengineparts.com/products_view.php?id=1256 . I would rather change pistons because you can go back to low comp if u want in a few years. Head and block milling cannot be undone. To get the heads and block milled it will cost alomst as much as the pistons and rings.

Just my 2 cents.