possibly need valve springs?

gxnos · Apr 24, 2010

I have an 86 shortblock with E7 heads and a MPT70 pushing 9 lbs, completely stock otherwise.

Right off the bat I had issues detonating and blowing out spark. We brought back the timing a little and I went with Autolite 23 plugs gapped at .028" and a MSD coil. I then continued to make 420rwhp without any issues. We only took it up to about 5200 because my max power was at 4900.

I took it to the track and ran into some problems in the top of 3rd and 4th. It was breaking up at about 5300 rpm. Wideband AFR was reading in the low 11s, and it wasn't blowing the spark out (thats a total misfire), and it didn't feel like detonation. It was like the feeling of running out of fuel, but it wasn't.

The only other thing I could come up with is valve float. This is a completely stock motor with relatively high miles. Does it seem logical I need a set of springs? I don't know what else it could be. I need to get this problem fixed because I'm topping my car out at the track. I hit 118mph and coast the rest of the way down. Also, what springs should I get, and who has the best tool for changing the springs on the car? TIA

gxnos · Apr 24, 2010

thinking about getting

Ford Racing M-6513-A50 - Ford Racing Valve Springs - Overview - SummitRacing.com

and

Summit Racing SUM-906784 - Summit Racing® Valve Spring Compressors - Overview - SummitRacing.com

or I might get the TFS springs because they arent much more and come with retainers, keepers, seals and shims

Trick Flow Specialties TFS-2500100 - Trick Flow® Valve Spring Upgrade Kits - Overview - SummitRacing.com

what do you think?

2000xp8 · Apr 25, 2010

When you say "stock", do you mean nothing at all other than the SC?
Fuel pump, meter, injectors?

I've floated valves before, the feeling and sound was similar to hitting the rev limter.

gxnos · Apr 25, 2010

stock longblock and intake. but I do have a walbro 255, c&L meter and green top injectors. the feeling is similar to hitting rev limiter, but kinda random. almost a rev limiter, haha. dont know how to explain it. sounds like I will be swapping out springs soon.

2000xp8 · Apr 25, 2010

gxnos said:
stock longblock and intake. but I do have a walbro 255, c&L meter and green top injectors. the feeling is similar to hitting rev limiter, but kinda random. almost a rev limiter, haha. dont know how to explain it. sounds like I will be swapping out springs soon.

Ditch the meter.
C&L's suck for NA setups, they are even worse with a supercharger.
Sounds like you have 42's which is a good thing, I'd get a PMAS meter calibrated for them. Or at least check to see if the sampling tube inside the C&L meter is correct.

I'd also check the msd coil, their quality control is in the gutter lately. I've personally seen them fail, brand new.

Without a cam, i'd find it unlikely the valve springs.

gxnos · Apr 25, 2010

2000xp8 said:
Ditch the meter.
C&L's suck for NA setups, they are even worse with a supercharger.
Sounds like you have 42's which is a good thing, I'd get a PMAS meter calibrated for them. Or at least check to see if the sampling tube inside the C&L meter is correct.

I'd also check the msd coil, their quality control is in the gutter lately. I've personally seen them fail, brand new.

Without a cam, i'd find it unlikely the valve springs.

A T70 is not supercharger, its a turbo, and I will have to disagree about the C&L meter. I have been using them for almost a decade, and had great results every time, and have only heard great things about them. They are one of few that work with a blowthrough setup. They pretty much have become the gold standard in mustang turbo setups. I didn't even need to tune it, although I did anyways. Air fuel was perfect across the board (14.7 at idle, in the 11s under boost), and all I did was change the tube.

If there was a problem with the coil, I would see problems as soon as boost hits. With the stock coil, it would blow out the spark every time it hit full boost. I have not seen that problem since I swapped the coil / plugs. Cap, rotor and wires are also all new.

Now that I'm thinking about it.... Stock seat pressure on an E7 valve spring is about 85 lbs. With 9 psi on the 1.78" intake valve, thats 50.2lbs subtracted from the seat pressure. That leaves me with about 35lbs, and with 5500 rpm, I could easily see valves floating. I wish I thought about this before putting the heads on

2000xp8 · Apr 25, 2010

gxnos said:
A T70 is not supercharger, its a turbo, and I will have to disagree about the C&L meter. I have been using them for almost a decade, and had great results every time, and have only heard great things about them. They are one of few that work with a blowthrough setup. They pretty much have become the gold standard in mustang turbo setups. I didn't even need to tune it, although I did anyways. Air fuel was perfect across the board (14.7 at idle, in the 11s under boost), and all I did was change the tube.

If there was a problem with the coil, I would see problems as soon as boost hits. With the stock coil, it would blow out the spark every time it hit full boost. I have not seen that problem since I swapped the coil / plugs. Cap, rotor and wires are also all new.

Now that I'm thinking about it.... Stock seat pressure on an E7 valve spring is about 85 lbs. With 9 psi on the 1.78" intake valve, thats 50.2lbs subtracted from the seat pressure. That leaves me with about 35lbs, and with 5500 rpm, I could easily see valves floating. I wish I thought about this before putting the heads on

Not sure i've ever heard anyone refer to a c&l as the gold standard, a good portion of tuners won't even tune a car with one since they are such a PITA.

But, if you like it, that's cool.
I've also been told that blow through meters peg sooner than draw through. The info comes from a very reliable source, although i did not get an expanation of why, at that time it wasn't relevant to me.

I didn't read you had a turbo, i just saw "boost".

If you really think its the valve springs, why not invest money in a better set of heads, instead of blowing money on E7's.
Even if you use a set of gt40 irons, at least those would be worth valve springs and a valve job. If you went to aluminum in the future you could get your money back. On the e7's it's like throwing money away.

gxnos · Apr 25, 2010

2000xp8 said:
Not sure i've ever heard anyone refer to a c&l as the gold standard, a good portion of tuners won't even tune a car with one since they are such a PITA.

But, if you like it, that's cool.
I've also been told that blow through meters peg sooner than draw through. The info comes from a very reliable source, although i did not get an expanation of why, at that time it wasn't relevant to me.

I didn't read you had a turbo, i just saw "boost".

If you really think its the valve springs, why not invest money in a better set of heads, instead of blowing money on E7's.
Even if you use a set of gt40 irons, at least those would be worth valve springs and a valve job. If you went to aluminum in the future you could get your money back. On the e7's it's like throwing money away.

I went a little different with this setup. I wanted to prove my philosophy that you don't need to spend thousands on a motor or other crap to go fast and have an awesome street car. I put a nice turbo kit on a bone stock 5.0, and made almost 500hp out of the crank with only 9psi. I don't want to upgrade the heads, because that will put me over 500hp and the block will become compromised. I am basically at the maximum power with a totally stock motor. People were blown away at the track when I wasted a modded shelby, running 11s while spinning and letting off, and I have stock motor, suspension, brakes Thanks for your thoughts, but I'd like to keep it as is.

Just out of curiously, what did you have when you experienced valve float? Was it N/A with a cam but without springs?

btw, you have a kick ass explorer

2000xp8 · Apr 25, 2010

gxnos said:
I went a little different with this setup. I wanted to prove my philosophy that you don't need to spend thousands on a motor or other crap to go fast and have an awesome street car. I put a nice turbo kit on a bone stock 5.0, and made almost 500hp out of the crank with only 9psi. I don't want to upgrade the heads, because that will put me over 500hp and the block will become compromised. I am basically at the maximum power with a totally stock motor. People were blown away at the track when I wasted a modded shelby, running 11s while spinning and letting off, and I have stock motor, suspension, brakes Thanks for your thoughts, but I'd like to keep it as is.

Just out of curiously, what did you have when you experienced valve float? Was it N/A with a cam but without springs?

btw, you have a kick ass explorer

Thanks for the compliment.
I figured it was budget, that's why i said gt40 irons, they are only like $250.

I had the valve float with a crane cam on stock heads. Something with similar specs to an E cam.

gxnos · Apr 25, 2010

ok now i have another question. i want to get the FRPP A50 springs, but I will need new retainers and possibly keepers.

Why does everybody get the A50 springs with the B50 retainers? FRPP says to use the A50 retainers with the A50 springs.

I cant see a difference. Both for 1.5" diameter, 7deg, Middle 1.060", Inside 0.675", and 11/32" stem

Also, do the E7s have come with a 7deg keeper?

oh and im not going with the TFS kit because they are on backorder until the end of next month.

5.0ina66 · Apr 25, 2010

gxnos said:
oh and im not going with the TFS kit because they are on backorder until the end of next month.

Both the TFS and Ford kits are backordered out the ying-yang, if I'm reading Summit's website right. Sucks too, I'm looking for a ~$100 valve spring kit myself.

gxnos · Apr 25, 2010

5.0ina66 said:
Both the TFS and Ford kits are backordered out the ying-yang, if I'm reading Summit's website right. Sucks too, I'm looking for a ~$100 valve spring kit myself.

Summit says the ford kit w/retainers and keepers ships same day.

On another note, i found out the B50 retainers eliminates the exhaust valve rotator. I dont know what is physically different, but I thought we wanted that?

gxnos · May 16, 2010

went with the A50 springs and B50 retainers, 6200 rpm revs and no problems!

the summit valve spring compressor is great. it still sucked, but the tool made it so much easier.

possibly need valve springs?

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