Added fresh bottomend (306), ported intake, and longtubes...gained just .8 mph...why?

[Speeds8erM-1]

Probably didnt pick up as much just on the account of it being a new engine, older engines can run just fine (not always) and new engines generally take awhile to loosen up. The 4 cubic inch gain can just as easiely be offset by tighter clearances, tighter ring gap, ect ect. Who's to say the car really picks up much with the ported intake or that it's working within your desired RPM range? Or that the stock tach is even getting you in the rpm range you need.

I think it's all that making fun of the 5.0 finally catching up with you.

 

[5spd GT]

Probably didnt pick up as much just on the account of it being a new engine, older engines can run just fine (not always) and new engines generally take awhile to loosen up. The 4 cubic inch gain can just as easiely be offset by tighter clearances, tighter ring gap, ect ect. Who's to say the car really picks up much with the ported intake or that it's working within your desired RPM range? Or that the stock tach is even getting you in the rpm range you need.

I think it's all that making fun of the 5.0 finally catching up with you.

What do you mean all the making fun of that I have been doing? What does that have to do with this Same night, I pulled the best time in the Mach 1 than the owner has every been able to

This same night, a couple of my friends weren't running as quick as they have been...so it could have been weather.

Yes, I realize the 4 cubic inch doesn't do anything, I don't count that as part of the "concern" but that I have more compression (not "worn-out")

Also I'm sure the ported lower actually helps, the longtubes, nah.

 

[Speeds8erM-1]

Who's to say the old engine was really that worn out? Did you do a compression test? You can easily lose some power with tighter tolerances and tighter ring gaps. The 306 should make a few more hp all else being equal but it might not be equal until it gets some miles on it.

 

[5spd GT]

Who's to say the old engine was really that worn out? Did you do a compression test? You can easily lose some power with tighter tolerances and tighter ring gaps. The 306 should make a few more hp all else being equal but it might not be equal until it gets some miles on it.

It had some oil blow-by, getting on the cc's of the head, spark plug. Also 164,000 and it wasn't easy miles either. Just common sense thinking...I just figured it would have did a bit better the first time out.

I know about the tolerances...it also has a better balance than from the factory. Lighter pistons...

 

[04sleeper]

My 60ft would improve if I did a burnout and my driveshaft wouldn't rub off the line...

What kind of control arms do you have David?

Have you checked your torque boxes?

Sounds like something is off.....

Your driveshaft shouldn't rub anything.

I have seen mufflers rub against the driveshaft before by not being adjusted right but not the driveshaft hitting the car.

 

[5spd GT]

What kind of control arms do you have David?

Have you checked your torque boxes?

Sounds like something is off.....

Your driveshaft shouldn't rub anything.

I have seen mufflers rub against the driveshaft before by not being adjusted right but not the driveshaft hitting the car.

Stock control arms, torque boxes are fine...

It hits my e-brake brackets, my car has saggy rear shocks and the wider aluminum driveshaft rubs...I've looked at it and it has rubber all over it...every little bit hurts...it isn't anything I hear or feel, but it is doing it

 

[04sleeper]

Stock control arms, torque boxes are fine...

It hits my e-brake brackets, my car has saggy rear shocks and the wider aluminum driveshaft rubs...I've looked at it and it has rubber all over it...every little bit hurts...it isn't anything I hear or feel, but it is doing it

Hmmm.

Saggy rear shocks would not cause the driveshaft to hit or rub anything. It might cause the tires to rub but thats about it.

All of my Fox's had aluminum driveshafts and were lowered. I never had the drivshaft hitting anything.

It sounds like your control arm bushings are whipped.

Also 164,000 and it wasn't easy miles either.

If your bushings were worn then it could cause your rear to twist rearward when you get on it.


How are your tranny and motor mounts?

 

[5spd GT]

Hmmm.

Saggy rear shocks would not cause the driveshaft to hit or rub anything. It might cause the tires to rub but thats about it.

All of my Fox's had aluminum driveshafts and were lowered. I never had the drivshaft hitting anything.

It sounds like your control arm bushings are whipped.

If your bushings were worn then it could cause your rear to twist rearward when you get on it.


How are your tranny and motor mounts?

Yeah it is quite possible...I bet you are right. The motor mounts and tranny mounts are in okay condition. I know by a visual that the bushings don't look to good. I do know that my front end is higher than my back...I can notice it.

I figured with the back end squatting, the rear gets closer to the bottom of the car and so would the driveshaft. There is about 3 inches between the top of the driveshaft and the e-brake bracket while it is just sitting there.

 

[25thmustang]

I will add my .02 here...

Number one, your motor could very well still be tight. A 160,000 mile motor although starting to lose compression, and burn oil, is broken in, loose and running hard. Loose is fast, anyone can tell you that. Knowing this, your bottem end may not have helped at all. The 308 compared to 302 CI is next to nothing, and unless you bumped compression with a better piston, will probably only help in the tq area. Now a good bottem end, offset ground crank, and loose, with flat tops, would have helped you out a lot, but a 308 rebuild with stock stuff, isnt going to gain much.

Number 2, although I say LTs helped my car a ton, you and I know it was just my case for some reason. I do know they make more power, but how much is more or less a toss up. Youd never know what they did without running shorties, then running the LTs.

Number 3, it sounds like an issue my dads car had. We found out it wanted to be reved. Car wanted to see 5800-6000 RPM, and with his tach (even his autometer) it was off and we were shifting it at 5400-5500. Needless to say we set the light for 6000, and the car gained a few mph (109-110 and now 110-112). Id say get a shift light and experiment.

Number 4, the numbers arent bad. I did an 8.4 @ 86 in the 1/8th which was a 12.9 @ 108 or so in the 1/4. Your cars probably hitting 12.7 @ 109 which makes for a nice street car. Id say shift it higher, and you could be in the low 8s.

 

[5spd GT]

I will add my .02 here...

Number one, your motor could very well still be tight. A 160,000 mile motor although starting to lose compression, and burn oil, is broken in, loose and running hard. Loose is fast, anyone can tell you that. Knowing this, your bottem end may not have helped at all. The 308 compared to 302 CI is next to nothing, and unless you bumped compression with a better piston, will probably only help in the tq area. Now a good bottem end, offset ground crank, and loose, with flat tops, would have helped you out a lot, but a 308 rebuild with stock stuff, isnt going to gain much.

Number 2, although I say LTs helped my car a ton, you and I know it was just my case for some reason. I do know they make more power, but how much is more or less a toss up. Youd never know what they did without running shorties, then running the LTs.

Number 3, it sounds like an issue my dads car had. We found out it wanted to be reved. Car wanted to see 5800-6000 RPM, and with his tach (even his autometer) it was off and we were shifting it at 5400-5500. Needless to say we set the light for 6000, and the car gained a few mph (109-110 and now 110-112). Id say get a shift light and experiment.

Number 4, the numbers arent bad. I did an 8.4 @ 86 in the 1/8th which was a 12.9 @ 108 or so in the 1/4. Your cars probably hitting 12.7 @ 109 which makes for a nice street car. Id say shift it higher, and you could be in the low 8s.

Thanks for the response Brian...

I do know that the 306 isn't going to do anything...I just figured (even though it was "super" loose) the increased used compression would help it. Oh well...no biggie. All in time...

 

[25thmustang]

No worries, im sure it will get faster as time goes by... My dads combo went 12.9-13.0 @ 105 first time out. Slowely knocked into the 12.6-12.7, then 12.3-12.4, then got it into the 12.1 @ 110 range by the end of the year. It was all in changing a few small things, tweaking it, and learning what it liked.

 

[Speeds8erM-1]

It's hard to make changes like that and come out and make a big different right off the bat. Look at it this way, how many times had you ran before you got your BEST? Comparing your BEST before to your first time out is kind of hard. You almost picked up almost 1 mph in the 1/8, thats a big gain for the 1/8, might have done more in the 1/4.

You will probably need some passes before you nail that BIG number like you did with your old setup. You might even need to shift it up higher than before with the ported intake.

I do belive a 306 can make more power, all else being equal, more cubes, although not but but you also get the valves unshrouded more. You wont see factory stock cars running standard bore and for good reason, you need all you can get. In this case though, you might need to get some more miles on the new bottom end before it's equal power wise with your old one. That is weird though since the other one lost compression, it should have been weaker.

 

[5spd GT]

It's hard to make changes like that and come out and make a big different right off the bat. Look at it this way, how many times had you ran before you got your BEST? Comparing your BEST before to your first time out is kind of hard. You almost picked up almost 1 mph in the 1/8, thats a big gain for the 1/8, might have done more in the 1/4.

You will probably need some passes before you nail that BIG number like you did with your old setup. You might even need to shift it up higher than before with the ported intake.

I do belive a 306 can make more power, all else being equal, more cubes, although not but but you also get the valves unshrouded more. You wont see factory stock cars running standard bore and for good reason, you need all you can get. In this case though, you might need to get some more miles on the new bottom end before it's equal power wise with your old one. That is weird though since the other one lost compression, it should have been weaker.

Many realize that the 306 "adds up"...but I was letting it be known that me putting that I "installed a 306 and was dissapointed" was not due to the fact since I had a few extra cubes that I had "more power there"...it is very minimal. I was more worried about compression...not the "cubes."

 

[rd]

Overall, that's not a bad time for a car at 3400 lbs.

The sixty foot is also not bad. My 82 has a best of 1.89/8.16/80 in the eigth on motor, with 4.10 gears at 2900 lbs. The short block was built in 87, and has 95k miles.

Just freshening up the motor most likely wont make a huge difference. My motor would not get out of the 15's in the quarter in my 3400 lb 79 Capri. The change from that to the 2900 lb Mustang helped a lot.

 

[jjd975]

If you build the exact same motor and ones a 302 and the other is a 306 your looking to gain close to nothing, maybe 4 HP for the extra cubes.

 

[DMAN302]

Not sure wether I buy into the 'will loosen up', I wonder if maybe your old mill just ran well for the miles logged. Second I might want to get the car on a dyno..perhaps your running fat and need to lean her up a bit, or get a bit more aggressive with the timing...just some thoughts.

 

[5spd GT]

If you build the exact same motor and ones a 302 and the other is a 306 your looking to gain close to nothing, maybe 4 HP for the extra cubes.

Yes, I know this. That is what I have been trying to say the whole time...

 

[5spd GT]

Not sure wether I buy into the 'will loosen up', I wonder if maybe your old mill just ran well for the miles logged. Second I might want to get the car on a dyno..perhaps your running fat and need to lean her up a bit, or get a bit more aggressive with the timing...just some thoughts.

Yeah I agree, I think the dyno will let me know if I'm actually putting out the power I think I am...I believe it is running rich...but the dyno would tell...thanks buddy.

 

[5spd GT]

Took the car to the track last night and did a little bit better...

1/8th mile was 8.27 at 87.33mph instead of the 87.01.

1000 ft time was still the same 10.5x time but ran at 99.31mph instead of the 98.51mph.

It appears the 306 has broken in and gotten a bit looser as some on here stated...

Just an update...

 

[DMAN302]

excellent..the miles seem to be working for ya, everyone keeps saying the loosen up,guess maybe they're right.