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Discussion Starter #1
i know you're always supposed to check p/v clearance but i'm lazy so... my combo consists of a stock 302 shortblock, track heat heads, f-cam and 1.6 roller rockers. i've been thinking of running 1.7 roller rockers. has anyone done this here with the factory pistons? will it clear or will i have to have them notched?
 

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If you have the 1.94" intake valves you will probably be OK, but if it's the 2.02 valve heads then nope! The factory notches most likely won't be enough.
 

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When you use track heat heads,the vavles are angled different and are nowhere near the vavle reliefs in stock pistons.I tried to put an X cam in and I had almost no clearance at all.An F cam and 1.7's will give you the lift of an X except you have more duration.I would not try this.I doubt it would run any better anyways.I had a B cam in mine before I bought a comp nitrous cam and the B was phenominal.I had a ton of torque at low r.p.m.The comp cam works just as well.My suggestion is to change the cam if you are not happy with the performance you have now
 

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Discussion Starter #5
WHLSTNDR said:
I doubt it would run any better anyways.
why is that?

WHLSTNDR said:
My suggestion is to change the cam if you are not happy with the performance you have now.
i never said i wasn't happy with my cam, now, did i.
 

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1.7's with an f cam is basically giving you .542 lift intake and exhaust with 226 degrees duration... if you were to call Ford Motorsport at 586-468-1356 you can confirm that they strongly advise AGAINST using the x cam with 1.94 intake valves (the x also has .542 lift intake and exhaust but with 224 degrees duration). They strongly advise against such close tolerances because even if it does fit with no p/v issues they say the performance is not so great due to the way flow is affected with the piston and valve being so close. They also say that if your springs weaken or if your piston rods stretch a little... then your pistons and valves could play tag in the future.
 

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The clearance issue is due to the valve size and the timing of the opening of the intake and closing of the exhaust valves. Peak lift has nothing to do with it. Bigger valves than your reliefs, increased duration/overlap or tighter LSA's are what reduce clearance. At peak lift the pistons are way down the cylinder with plenty of clearance. Read here for more detail on how to measure and why it's important to measure your combo - when it comes to hundredths no 2 are alike. http://www.geocities.com/jjonibones/PVC.html

If you think you're too lazy to measure, imagine how bad such laziness will feel when you have to pull it back apart to replace bent pushrods, bent valves or a piston or 2 that holes in the top of them. But, it is your choice.
 

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Twisted wedges come with 2.02 valves, always have. The intake vlaves are rotated towards the center of the piston so they work like a 1.9 valve head thats the normal inline valve configuration with the stock reliefs.

IMHO, its going to be close enough to check and see your clearance if you want to do it.......the exhuast side will be fine, but intake could be close.

Any times with your current setup? Whats the rest of the motor/exhaust?
 

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....and, forgot part of the original question. At lifts where clearance is an issue (around .050" for cams like yours) the difference in clearance between 1.6's and 1.7's is only 3 or 4 thousandths of an inch. So if you've been ok with the 1.6's then you'll likely be ok with 1.7's. On the other hand, if you didn't measure originally, and your clearance is very tight (.080" intake min./.100" exh. min.), then the rocker could put you a bit below the min. And, unless you've missed a shift and floated the valves a bit, you still don't know that you've got enough clearance -- unless you measure.
 

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Hey man,I was just trying to help with your clearance problem.You don't have to start jumping on me.I have tried the 1.6 and 1.7 rocker switching several times.I never noticed a difference.If you are so happy with the cam,why are you trying to change the lift with 1.7's?I could care less what you do.Put the 1.7's on then.See for yourself
 

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Discussion Starter #11
WHLSTNDR
i simply asked what makes you so sure that 1.7rr won't help and then stated that i'm happy with the cam. sorry if i hurt your feelings.

N2O88
my combo consists of a stock 302 shortblock, which i freshened up few years ago, track heat heads, rpm intake, f-cam, bassani longtubes (158-134), bassani 2.5" x-pipe, mac cat-back, f-cam, 1.6rr, 75bullet, 75tb, 24#, 373, knn (factory air box), no porting and stock compression. i ran a 12.3x at nearly 112mpg few months back but that was with a junk t5 (i'm installing a new one this week) and a slipping clutch (al flywheel and spec 2 clutch going in). the track prep wasn't the greatest that day and neither was my driving so i'm sure there's LOT more left in it. it's just a matter of everything coming together at once (car/driver/track).
 

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Sounds good man. Whats your tune? Im guessing around 18 initial and 45psi vac off on the fuel? Should see some 114 ish traps next time out.....just get it to the ground and some 11 sec slips should come up. What raceweight?
 

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Discussion Starter #13
thanks N2088. timing is at 18 (initial) and fuel is at 42-43 psi vac off). i'm not sure how much the car weights but my guess is that its around 3050-3100 or so and i'm just about 200 so it's not that light. i think the biggest problem, besides traction, is that i could use more gear. 410s would definitely put this thing in the 11s but i'm going to try hard as hell to run 11s with 373. there's still power left: al flywheel and powerpipe. i might even bypass the power steering for that extra few ponies :)
i was going to try 1.7 rockers but don't feel like dealing with the p/v (those bassani longtubes are a pain to deal with). i think 410s would be a smarter move.
 

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4.10's will make it easy, but al it really takes is a hard launch (6k-6200 ish) and some slicks with hook and you should see a high 1.5 and 11.80's or so.
 

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You're going that fast w/o a power adder and you did this w/o slicks.?That is really fast to me.I wouldn't touch that.I'd be afraid of doing anything to slow it down.The 4.10's should help though.What was your 60 ft. times.I am really interested because I am running alot of the same stuff.

fresh stock short block.Track heats,RPM intake,24#.73 C&L,65mm TB,3.73,longtubes,bbk h-pipe,race magnum mufflers.I have fuel press. at 40(vacuum off),and 17 degrees of timing.Mine runs really rich though and I don't know why.I have 460 injectors.Could they be the problem?I went [email protected] with a 2.2 60 ft with street tires.I noticed you have a big tb.Did you ever run a 65mm.Is mine to small.I have an NX kit on my car I haven't used yet.I run it to run a mid 12 on the motor.If I can get it to do that I shouldn't have a problem running 10's with nitrous.Any info would be greatly appreciated.
 

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Discussion Starter #16
N2O88 said:
4.10's will make it easy, but al it really takes is a hard launch (6k-6200 ish) and some slicks with hook and you should see a high 1.5 and 11.80's or so.
i'd settle for a 11.99
:D

WHLSTNDR said:
You're going that fast w/o a power adder and you did this w/o slicks.?
no power adder but the 12.3 was on et streets. last year i ran a 12.80 @ 110.xx mph on 235/45/17 nitto dr. at that time the car was making like 316rwhp & 320rwtq.

WHLSTNDR said:
40(vacuum off),and 17 degrees of timing. Mine runs really rich though and I don't know why. I have 460 injectors. Could they be the problem?
every meter/car is different and that's where a dyno comes in. my car made best numbers at 18* timing. i tried 20* but it made no difference. what are 460 injectors?

WHLSTNDR said:
I went [email protected] with a 2.2 60 ft with street tires.
i'm sure there's more left in it. get it dyno tuned and get to the track.

WHLSTNDR said:
I noticed you have a big tb. Did you ever run a 65mm.
i switched to a 75tb this year and gained few (4rwhp or so) ponies across the board so it did help. driveability did NOT suffer like some thought it would.

what came are you running?
 

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Discussion Starter #18
WHLSTNDR
sounds like you just need to dyno tune your car
 

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Discussion Starter #20
i don't really remember but dyno tuning is definitly worth it, especially that very first time to get your base tune.
 
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