motor planning, what to expect? (solo)

[groho]

Finally, after many years, got my 66 mustang into paint. Sheetmetal is done, subframes, torque boxes, tranny is built, suspen is done. I plan to attack the motor over the next couple of months while I have the extra space in the garage. Pulled the motor and see my block is a '68 302, so I have to bust it down to the short block anyway for the heads, I also need to determine if its an actual 302 or a 289. I'm reading as much as possible to carefully choose the parts and keep my costs down. What RPMs can I expect to see in solo racing? I plan to drive the car to the event, race, and drive home, weekend fun, etc. I do want it to be managable on the street in traffic without scaring the crap outa my wife. Am I over the top planning a build for 6500 routinely, and redline at 7000? I'm thinking along the lines of AFR185, with upgraded springs, and 510 lift, 225 dur (@.50), 110 overlap hyd. A roller cam upgrade is not out of the question, but I'm not strong on roller cams, and its something I could really use some advise on.

[Jetfixr320]

Where are you located? I know a few people that could help you plan and or build it.

[groho]

Jet, thanks for the kind words, I'm located in northern CA. I learned a long time ago you don't have to have brute horsepower to be fast. I'm a total newb to this but always wanted to run a corner carver over a straight line. Did it in my SRT at Laguna Seca, and was immediately hooked. I've been working on this coupe for 5+/- years, and after I drove a cone course I decided to take the plunge and move from weekend driver to FUN! weekend driver. Broke the motor down this weekend. The motor is a '68 302, .30 over, with a 10/10 crank. All looks very good and rebuilt in the last year or two by the prior owner. Plan to pick up the Compcams Xtreme energy cam (520lift/280dur) with AFR165 heads. My objective is to be quick, not fast. C4 is already built, rear will be changed from 3:25 to 3:80 with the extra center I have. I have SSBC brakes currently, and think they'll need a pad & rotor change before this is over. Other than the need for a panhard bar e(maier racing) the susp is pretty well set dropping the car 2" all around. Steering is key, so I'm looking at TCP R&P which is right down the street. I'm moving in the direction I want, just hope I can complete it before I reach social security.

[SSLance]

What RPMs can I expect to see in solo racing?


That really depends on who is putting on the events you'll be attending and the sites they choose. I attend SCCA events regularly and I typically see 45-60 mph top speeds which with my T56 and 3:50 gear tops me out at 5500-5700 rpm max in second gear.

Personally, I'd build the motor more for torque than high RPM which will give you more power to pull out of a corner which will help you more than high rpm power which you won't see until right before you hit the brakes again. You don't want to have to be shifting, try to keep everything matched so that you'll get max power between say 3,000 and 5,000 RPM, 40 to 55 mph or something like that.

This will also make for a very fun driver for the street. Might be tough with a 3 speed trans though...is an OD trans or a 5 or 6 speed manual out of the question?

[bmpmd]

A 306 I built for a friends 62 Falcon might be exactly the combo you would like. I used Performer RPM heads cut to a 56cc chamber cc,, A Weiand Stealth intake, a Lunati VooDoo cam (after testing the cam you mention plus a couple others on the dyno,) , part# 20350711, with 221/229 duration @ .050" lift, .549"/.565" lift, and tho the catalog has it on a 112 LSA, we had it ground on a 110 LSA, 1 to pick up the response and 2) to shorten the rpm range down a couple hundred rpm because of the stock Connecting rods. Made 417 hp, 416 tq and never sees 6200 rpm.

[bmpmd]

A 306 I built for a friends 62 Falcon might be exactly the combo you would like. I used Performer RPM heads cut to a 56cc chamber cc,, A Weiand Stealth intake, a Lunati VooDoo cam (after testing the cam you mention plus a couple others on the dyno,) , part# 20350711, with 221/229 duration @ .050" lift, .549"/.565" lift, and tho the catalog has it on a 112 LSA, we had it ground on a 110 LSA, 1 to pick up the response and 2) to shorten the rpm range down a couple hundred rpm because of the stock Connecting rods. Made 417 hp, 416 tq and never sees 6200 rpm. He runs a 3.55 rear gear in it. It's easy to drive and quick though his top loader 4 speed trans.

[groho]

The C4 was pro-built by ATO transmission with a custom valve body, with rigid bands, extra clutches, C-servo. I'll be using a 24-2500 stall converter. I agree, a manual would be nice, but I don't think I could do better with another AUTOMATIC transmission. Jim @ ATO (Advanced Transmission) is no doubt one of the best tranny builders in northern CA. I'm currently running a 3:25 trac-loc, but have an extra center section. Originally, this was just gonna be a street car, but my, how plans change. I'm thinking a 3:73 would be just about right, but want to see what the current center does for me before I make a gear choice. I think I've settled on the XtremeEnergy XE274H cam @.50 is 520/523 lift, 230/236 dur. I can't believe the amount of reading and studing this involves to get the right combo. I've looked at rollers, solids, and hyd.. Constantly trying to find the right combo without going too big and killing the low end.

[bonesfab]

As stated above, torque is more important than horsepower.. 90% of most driving is idle to 3500 rpm. And small block fords lack torque already.. Especially being an auto trans.. I would recommend a hydraulic roller just for longevity and a little more power.. Standard flat tappet cams are having issues wiping out the lobes from the oil content being changed over the years.. Just my opinion.. Jim

[GrabberGT]

After seeing how well Mike Maier did at the Goodguys finals last year with a 306 against MUCH more power, Im convinced, a smaller motor can be competitive on just about any course. I have no idea what the internals were on it but still impressive. I run a 347 with AFR185 heads and an FMS X303 cam. I always felt that I was lacking the torque needed to be competitive on the tighter, more technical GG courses so with my latest motor, I decided to give comp cams a call for a suggested CAM upgrade. I now have a XE282-HR. I have yet to run it but it should give me more of the lower end torque I am looking for. Duration at .050 232/2440 and lift .565/.574 .

I have a set of HR conversion lifters I no longer need if you are interested in making the switch. Just PM me and we'll discuss the specifics.