289 Hi Po Build Up Issues?

[lashss]

I'm nearing a vintage 289 HiPo build up and wanted a few thoughts from the
veterans out there. The engine will be used in a smallish (2500lb) car for
track events and road ralies.

What is the maximum bhp I can expect to achieve in a reliable form on 94
octane + octane booster? I have no standards (nor do I care) about idle
quality or low end torque. I only care that it actually does idle by
itself and be run on Webers.

What are the known problem areas on 289/ HiPo engines that should be
addressed for open track and/or long term high rpm reliability? Main
girdle? Forged aftermarket crank? 4 bolt main conversion or some sort?
Anyone have personal experiences on combos that work?

I know this is a ridiculously open ended question on the order of "I just
got a Mustang, how do I make it handle?". Please go ahead and throw some
thoughts out there.

Thanks,
LS

[eljimb0]

A motor is just the sum of it's parts. You say you are starting with a "vintage" HP motor (271 horse "K" motor?). How much of the motor do you plan to use? If you are going to make serious HP you can begin by tossing every part of that motor except the connecting rods.
jimbo

[M Farcus]

If there are no rules....maximize the cubic inch and keep the rpm down....I'd start with a later 302 block and at least a 302 crank...lots cheaper than trying to find 289 stuff. For all out performance on a 289, throw everything away except the block...max 0.040 over bore assuming it passes sonic testing. I vintage race a GT-350 built to the 67 GCR. We run a 0.040 Hipo block with girdle, and all good parts inside, OEM Windsor heads and a dual plain intake. HP is near 500 with 13:1 compression. To get more than that you need better heads and intake which is not legal under our rules. Get a good set of aftermarket aluminum heads, single plane intake and you can get over 500. For track events in a 2500 lb car, 400-425 hp will do nicely. Its easy to make HP...much harder to make longevity. Our race motors always get rebuilt at 30 hrs, max. Normally the only thing we need to do is replace springs, touch the valves....Altho the last time, at a bit under 90 hours, the crank was cracked and two rods tweeked....keep the cost of maintence and upkeep in mind when building HorsePower. On a roadrace car, it takes a lot of HP to make much difference in lap time...spend money on suspension, and track time....

MF

[eljimb0]

Yeah,
What he said.
jimbo

[Sandy Galbraith]

Well for my 2 cents worth I would agree with most of whats been said. I would definitely go with internal balancing and with a decent fordged or billet crank. I had a cast crank come apart coming out of the carousel at Sears Point and it scared the crap out of me. Ruined the whole engine except the heads....so money spent in that area is well spent.

You can save some money going with Eagle rods...I haven't heard anyone having any problems with them. Piston...well thats pot luck...lots of good ones to choose from...personally I went with JE. Heads....well I think the AFR now are the best....but expensive. But in the end you will never be dissatisfied with the best....you may be broke but happy!!! Good luck

[lashss]

Thank you for all the suggestions and replies. This is what I have to work with:

289 Hi Po block (well, you know what I mean...HiPo caps, etc.)
HiPo heads
HiPo Connecting rods-Pistons
Shelby Intake
Correct '66 GT350 carb (can't remember which one though)
Tri Ys
289 Crank (OEM I believe)

I would like to keep as much stock or correct as possible. Besides adding a girdle, what absolutely critical change would you make? And any tips on maximizing the potential of these stock parts?

Thank you,
LS

[eljimb0]

If you use your parts..... with pump gas.... and a camshaft that has big bumps you are going to max out below 350 horsepower...(well below)
clean up the HP heads..Make sure everthing is balanced perfectly.... make sure the ports are all matched. Make sure the block is lined up good. It will still throw your 2500 pound car around like a rag doll. I personally wouldn't bother with the girdle.

[shlby66]

If you are planning on doing some vintage racing, perhaps you should obtain the rule book from the Racing Association you wish to compete in. That should give you some definitive direction as to what you can do. Some
oganizations have tightened up rules, some haven't.

Depending on what you want from an engine usually determines what must
be done machine wise. Then, the selection of parts must be compatible with
each other for best results. Probably an indepth discussion with at least two quality engine builders to answer all of your questions concerning your
engine project is in order. Listen to what they tell you. Block out the rag-mag gee whiz articles on engine building and pay attention to the pros.

Just remember: The rule holds true today as it did 40 years ago. And that
is... Speed costs money, How fast can you afford to go?

So with a big expenditure on the horizon, seek out professional advice. It
will save you money in the long run. ( reliability )
Good luck!
shlby66

[M Farcus]

Agree with shlby 66. Speed cost money, how fast do you want to go. "IF" you ever think you might evolve to any vintage race organization that has rules....check on the rules now. Don't do anything now, that may be illegal later. Rules are getting tighter in Vintage Racing...I race with CVAR, we go by the original GCR's and PCS....with a few exceptions made for durability and cost......you really don't need a killer motor, but rather one that is dependable and worry free...something you don't have to worry about. This will let you enjoy the track time....

MF