Ok, have a fresh 306 in my 92 F150. original engine was a hydraulic roller 302. E4OD trans, 3:55 gear. number 8 piston decided it was done. engine was really sludged up. all peripherial parts were tanked and/or jet cleaned.

This is the build:
302 roller block. stock crank polished, rods rebuilt with ARP bolts. sealed power H273cp pistons, basic flat with four big valve reliefs. pistons .011 in the hole. bottom end balanced with a new pioneer balancer, stock original flexplate. new stock oil pump. all new bearings, including cam bearings. .030 over, honed with a plate.

heads: ported GT-40p's, light back cut on the valves, light portwork by me. flowed very well on a flowbench, up near 200 on the intake, 165 or so on the exhaust. valve springs,~ 120 lbs on the seat. stock valves, needed to use a +.050 keepers on the exhaust to get the installed height correct.

cam: flat tappet comp 35-255-5. comp lifters. new stock pushrods for a flat tappet early 80's 302. 1.6 aluminum roller rockers. pedestal mount setup.

intake: stock truck 302 with light gasket matching to the heads.

exhaust: gt-40p mustang coated headers. modified Bassani regular 2.5" y-pipe(you only need to modify the drivers side), after market cat & cat back. stock intake, tb, air box and all that.

new timing chain, gaskets, cam is straight up. stock E4OD trans & converter. 31" tires.

Ok, I have dozens of small block fords, both flat tappet and hydraulic and have never heard a hydralic cam sound like a solid cam, has that really mild clatter sound when hot! oil pressure is about 25-30 psi hot at idle. cannot hear this when the engine is cold.
It make enough noise that it drives the knock sensor crazy... when is it screwed into the block the timing goes nuts at idle... currently the sensor is out of the block and zip tied to a bracket... this probably explains the poor performance if the computer is in a limp mode or something.

the engine does not make a ton of power, I was expecting more. starts to pull a little better at 3K and I may be expecting too much out of a 302 in a 4K lb truck. if the cam wasn't noisy I would advance it 2 or 4 degrees and deal with it.

anybody get lifter noise from any of these comp XE lobe designs? I know they are aggresive, but don't think it should sound like this...?????????????????????

my plan is to slide in a stock mustang hydraulic roller with some 1.72's and forget about it...probably

oh and for anyone looking to run this cam, gt-40p heads and 1.72 rockers you need to change the exhaust valves because the installed height stock is down around 1.580 and the retainer to guide clearance won't allow it. just for anybody's reference.

any body want to buy a comp cam & lifters with 7500 mile on it cheap?


by the way, the cam & lifters were well coated with molydisulphide lube and I have run nothing but rotella T in it after the first 20 minute breakin & oil change.

 

did it make the noise from the start or did it take a few miles....?

did you save the oil filter that was on it after the brake in?

why did you got with a flat tappet?

what are the specs on comp 35-255-5 cam...this number means nothing?

when you changed the oil after the first 30 minutes of run time what did it look like ? was it metalic looking?

if it's the XE274H cam..thats your problem...been there done that....

 

i dont understand why you went with a flat tappet as well, not to mention thats a 5.8 cam not the 302 cam. did you install new lifters? are you sure about all your torque sequences on the valve/pushrods. could the noise be a loose exhaust manifold or exhaust leak?

 

You won't be happy with the stock mustang cam in a truck... no matter how far you advance it.

Again... why would you go with a flat tappet in an OEM roller block? Comp cams
35-349-8, and 35-308-8 would be suitable off the shelf grinds for your setup.

 

more detail:

Ok, I did check the drain oil after the 20 minute break-in, no glitter... was noisy from the beginning. I have shimmed the rocker pedestals up & down with no difference in noise, the lifter preload is about .030"

I went with this particular cam because I have seen it recommended for a speed density system in a truck, that is what comp advertises it for as well. I would have gotten the 31-355-8 for the 154 firing order, but did not realize they even made it in both firing orders till I had it in my hand.

yes, of course I used new lifters! Wow I did not think anybody would put used flat tappet lifters on a new cam...

Both of those hydraulic roller profiles have too much lift for the stock valve spring retainer to guide clearance. you should have at least .030-.040" clearance there. There is only about .515 total there, so you can't have more than about .475 lift at the valve.

the specs on the cam are this:
210 deg intake dur. @ .050, .475 lift intake, 216 dur @.050, .485 exhaust
114 lobe separation.
it is the XE 254H-14

a stock mustang roller cam is about the same duration @.050, with .444 valve lift with a 1.6 rocker, and a 115 lobe separation.

noise isn't an exhaust leak, checked I rechecked that. sounds like a quiet 271hp solid lifter 289 in a 65 mustang.

Thanks for the help & advice but those grinds won't work for me unless I either by a set of exhaust valves of normal height.

I'll report back once I figure it out... after a partial teardown.

Jeff.

 

only thing I can think of is valve guides.....that cam should make no noise

I don't understand what you had to do to the valve springs/ retainers???....I have run .500 lift cams with stock retainers no problem....

Are they stock springs?
what is the install heigth of the spring?
did you install the spings to get the lbs you wanted and now the are binding at full lift?
where do those springs bind?
or are the new spring installed at their recomended height....

did you clean the guides real good after you ported them?
or did you port the heads with the valves installed...and never removed the valves to clean the guides?

sorry but I have seen people port the exhaust with the valves still in the heads.... not good for the guides...they have to be real clean.

did the install heigth of the valves change...did they need to be cut alot to get a good seat? if so those rockers will need to be shimed and longer pushrods installed if you run out of preload.

the only reason you need to shim the rockers is if the install heigth of the valve changes.....not to get the proper preload.

Need to know all this stuff ...you are far away...

 

sorry bud you are not getting it. the factory installed height on the exhaust valves on a gt-40p head is pretty short. with an aftermarket one piece retainer I had to use a +.050 keeper to get the installed height up to 1.740. the springs are single with damper, 115 @ 1.750 on the intakes, 120 on the exhaust @ 1.740.
going back I would have bought a set of regular length 1.46 exhaust valves for the p heads, and if I take it apart and find something bad, I just might.

have you ever seen somebody do port work with the heads assembled? good god they should just not be taking things apart.

I have built a ton of these things before and yes, the heads had the valves ground and were tanked after I did the bowl work. The guides are ok, the valve sweep across the valve tip looked great. the valves were barely touched on the grinder, and a small back cut to help low lift flow, which worked out nicely.
the block wasn't decked, the heads were not shaved.
And you absolutely use rocker shims to set proper lifter preload.
I'll let you know how it looks when I pull the valve covers.
Jeff.
and your truck sounds pretty good on the dyno run

 

Look Bud,,,,,,I ask all these ? because I'm sitting hear at my house not yours I'm just trying to help....
and yes I have seen people grind on the exhaust port with out taking the valves out and cleaning things...I think I already said that.....


AND YOU DON'T SHIM THE FUUCKING ROCKERS TO CORRECT PRELOAD, IF YOU DO THAT YOU FUUCK UP THE GEOMETRY, IF THE VALVE AND SEAT WAS CUT AND THE VALVE IS KNOW SAY .030 DEEPER IN THE HEAD THEN YOU NEED TO SHIM THE ROCK TO GET THE GEOMETRY BACK.

Sorry for trying to help......

...if I need more spring heigth I cut the pocket.. But you already knew that....

Good luck... I'm done.

 

One more try....

if you had to raise the retainer to get your spring heigth right ...then there is a good chance the rockers is hitting the retainers....

why didn't you just cut the spring pocket.......guess you already knew that too.

 

So what was wrong with it.......?

 

was this .030-.040" clearance including the valve seal?if so then disregard this post.what was the installed height on the springs?

 

holy crap hemi eater unwind your panties! jeez, I said you're not getting it because I am not explaining myself correctly.

I have not had time to pull it apart, looks like I'll not be able to get to it till after christmas now.

ok, the factory exhaust valve in a gt-40p head has the keeper grooves lower than any E7 stock head exhaust valve setup I ever took apart. the factory installed height was about 1.580 with the stock thick rotator style retainer. with a one piece aftermarket retainer it was about 1.690. I used + .050 keepers on the exhaust side to bring the installed height up to 1.740" which should have given me enough retainer to seal & guide clearance.. I did check this while the heads were at my machine shop as I did not have a valve spring height mic. the springs are a single w/damper, were right at 115-120 @ 1.750 installed seat height.


bronco, now you are making me second guess whether the .030 clearance was with the seals installed... the valve covers will come off and I'll be pulling the rockers and springs to have a look...

hemi, the rockers hitting the retainers is something I did not think about. I'll check that to of course once it is apart.

if this Sunday is decent out here in chicago, I might have a chance to get the drivers valve cover off then.

will report back.

Jeff.

 

You might also need to mark the top of the valves with something to check where the rockers are actually riding on the valves. Could be side loading or something. Last months MuscleMustangandFastFord mag has an article where they got their new boss 302 engine (Windsor heads) and it broke the same rocker stud twice due to the pushrods being too long. They also noticed that the long pushrods were causing the rockers to ride off to one side.
Just something to look into as well.

 

i was wondering if you ever found anything out?

 

You'd have been better off reusing the stock F4TE roller cam and using 1.7 rockers. The specs between it and the XE254 are damn near identical. As for the valvetrain noise , you will get more with roller rockers, all mine do. None are using a knock sensor though, both are carbed.