Is this cam a horrible choice?

[Tony71502]

The block I got has a B cam already in it. It's a fresh block and about to get thrown into the car. The heads are slightly molested e7's. Trickflow lifters, comp cams rockers and pushrods. UD Pulleys, longtubes, xpipe, catback.

Is this cam going to cause crappy driveability? Is there a more ideal cam to go into a stock long block. This motor may get an H/C/I in the future but a different cam will go in at that point. I would reuse the stock cam but at the very least I would expect the B cam to make things a bit more lively.

[Rodeheaver's]

that cam will be fine, the b cam is not a bad choice at all imo..

[Killercanary]

For a mild H/C/I on a stock shortblock the B303 with 1.7 rockers isn't bad and would be the only alphabet cam I'd even think of running.

[Tony71502]

I'm going back to 1.6's ... unless they are 1.65's... because the 1.7's are what bent my current valves.... damn float. It's a stock longblock, btw.

But, if it will work, good. I don't feel like buying another cam.

[White5.0]

get a valve spring upgrade while your at it...the 1.7's didnt cause your valve float, its the crappy @$$ stock springs. trickflow makes a kit

[Tony71502]

Ehh, I'm not putting the time or money into changing springs / buying new rockers for use on e7's. Yeah I know the springs were too soft, otherwise I would have grabbed a new set of 1.7's instead of the 1.6s.

Off topic question: What is the stock egr spacer/throttle body bore? If I got a 65mm egr spacer would it be different than the stock intake/throttle body? Can I just bolt the throttle body to the intake plenum?

[billyNOTnice]

you want that cam... nothing bigger would even be worth it.

[LX2NV]

that cam should work well. i have had excellent luck with b cams with stock and iron 40's. last time i used a b cam was in a 85gt with gt40p heads... ran 13.20's all day ! any more lift then that on stock or gt40 heads and you're wasting it's time !

[yeahloh95]

i like the e -303 it has has a furosis "sp" idle i like all the "letter" cams

[Tony71502]

There won't be any PTV clearance issues on stock heads, will there?

[mlowry1260]

Tony,

that cam should clear the stock pistons. Do yourself a favor & upgrade the stock springs, retainers & locks. You're lucky you only bent some valves. Ask me how I know...
http://images2d.snapfish.com/232323232%7Ffp536%3B%3B%3Enu%3D32%3C7%3E463%3E%3A% 3C7%3EWSNRCG%3D32%3B9%3B68452336nu0mrj

http://images2c.snapfish.com/232323232%7Ffp536%3A%3B%3Enu%3D32%3C7%3E463%3E%3A% 3C7%3EWSNRCG%3D32%3B9%3B73595336nu0mrj

[Tony71502]

These heads have been gone over before I got them, so IDK if the springs are stock or not. But since I'm not using 1.7 rockers how much of a difference can it make? I'm using new 1.6 Comp Cam rockers. I'm not really interested in putting any money in these heads aside from having the deck milled to make sure it's flush with the block.

I mean if it's some serious sh!t I guess I could replace the springs and hardware. Does that require a machine shop or just a valve spring compressor.

[mlowry1260]

It is serious chit Tony. You don't need high dollar valve spring for that cam. It's not a place I would recommend just any junk on either.

http://www.summitracing.com/parts/TFS-2500100/

These may work for you. They need to be setup by a shop so the spring pressures/installed heights are correct on all valves.

Learn from others mistakes...

[Tony71502]

What was yours damaged from? PTV interference? Having a shop change springs is another couple hundred.. >_<

[White5.0]

its not a couple hundred....i got mine changed for $90

[mlowry1260]

What was yours damaged from? PTV interference? Having a shop change springs is another couple hundred.. >_<

A broken valve spring...

[Tony71502]

its not a couple hundred....i got mine changed for $90

Hmm, where at?

[White5.0]

Hmm, where at?

broughers machine shop on 51 near century 3 mall. theyre a very good machine shop with a good reputation. if you're getting things like that done, i suggest going to them

[redneck15431]

I'm running Cobra 1.7 RR's with a B cam, and GT40 irons and no PTV issues. But yes I would get some stiffer valve springs just so you don't run into any issues.

[Mark Aubele]

Changing valve springs is really easy, just buy or borrow a good tool to do it.

[mlowry1260]

I agree that changing valve springs is easy. If these heads are used, at least lap the valves. You should set them up by installed height at a minimum. I use a valve spring micrometer. The best way is at a shop where they check & balance the installed height & check spring pressure.

If you need to do this as cheaply as possible, borrow a spring compressor & a spring micrometer & set them up at the same installed height using shims. Lap the valves to make sure you have a good seal at the seats. Clean everything twice & make sure you get all the lapping compound off of the heads/seats/valves.

[Tony71502]

So, explain to an engine newby how you check installed spring height, lap valves, or install shims?

I know how to replace valve springs and that would be no problem. But I figured you had to replace more than just the spring, and something in there requires machine shop work.

[Killercanary]

To properly replace the valve springs you have to know their installed height so that you ensure that you have enough seat pressure. Installed height is the distance between the spring pocket on the head and the bottom of the valve retainer. Basically you put in a valve, spring cup, retainer, and lock and set it up so that the valve is in the closed position but there is no valve spring in place. You then measure from the top of the spring cup to the bottom of the retainer to determine your installed height. You then use a valve spring pressure checker to see how much lbs of pressure the spring exerts at that installed height. If its too much then you can use things such as +.050" locks, different retainers, etc to raise the installed height which will lower your installed spring pressure on the seat. If its not enough you can run spacers under the valve spring pocket to shorten the installed height to raise its seat pressure. You must be careful here though to ensure that you do not end up with coil-bind in the spring at max lift as that can be catastrophic. I'm not sure what the OEM spec is for seat pressure on stock heads, nor do I know what it is for the B cam, but I'm sure you can find that out somewhere. Most cams will tell you what minimum spring pressure is needed, this is determined by a number of factors such as ramp rates, duration, etc. I doubt you'd need anything over 120lbs on the seat for a B cam and stock heads, and that may even be a bit high.

Time, mileage, and heat all degrade spring pressure so when you hear of old tired valve springs all this means is that their pressures are reduced from when they are new. For instance if you put in your new springs and they have 120lbs on the seat when installed and you pull them out a few years down the road and re-check them they will be a good bit less than that. This is the major cause of valve float with high mileage stock heads. Add boost from a supercharger and it makes things even worse as you have pressure trying open the valve which also reduces springs pressure. With some simple mathematics you can get an idea of how much spring pressure you lose per lb of boost by figuring out the area of the valve and the amount of boost you are running to determine what pressure opposite of the valve spring is being exerted and subtract that from your installed seat pressure. the bigger the valve, the worse this is and the more spring pressure is needed to counteract it.


You can do all of this yourself, the only special tools needed are a valve spring compressor, a magnet to get the locks out, and tools to get the installed height measurements and valve spring installed height pressures. If you can determine your installed height with a mic you may be able to take your springs to a machine shop and have them check them for your installed height measurement as most people do not own a valve spring pressure checker.

[Tony71502]

Well I'm going to just have Broughers install the valve springs. The question is which ones to buy? Do I go with the trickflow stock head upgrade kit that lowry linked?

Or do I go with Ford racing A-50 springs and B-50 retainers which was recommended from a member on a different forum. I need to learn how to shop for valve train parts. :)