Effect of tight lashing and / or hydraulic lifters on a solid roller camshaft.

[MeanGene]

I will make a suggestion and then shut up. Instead of continuing to fumble with this, send Brent all the parts/specs from your engine, and let him set you up with a cam/ lifter/ spring setup. Give him all the specs he asks for, and let him do it. Should work fine after that, he's pretty good on cams.
Or don't lol 

[Barry_R]

All of the stuff that's been discussed are "ragged edge" tuning deals that do not/should not apply to your level of build.  EMC was a cylinder pressure oriented competition and we tried all that stuff as we worked to maximize low RPM power and torque under load - long term durability was not a concern.  I did reduced crevice volume, very short travel HR lifters on solid lobes, solid lifters on HR lobes, near zero lash, radically advanced or retarded cam positions, positive deck clearances, ridiculous fuel mixtures in both directions.  Some of these are fun to talk about and gave incremental gains in certain builds - but your kind of deal should be "very normal" and none of this kind of cool stuff should apply.  You simply have the wrong cam for your application and need to change it.

I will say that a 13.6 A/F target for EFI seems very lean for an initial tuning setup.  Remember that a single O2 sensor is an average of the four on that bank.  Part throttle tuning variables on the intake could really screw things up.  You could have one at 15.4:1 and three at 13:1 & still see 13.6: at the sensor.  Get the target further into a range where we absolutely know it's going to be safe in variability ranges.  Somewhere in the middle 12s will always run OK even if not optimum.  Same as all the other cool things.  You should not be working around the edges of the "possible gains" - those are for after you've establish full control of the combination.

[blykins]

Is that oil on the threads or some kind of left over anti-seize?

 

[DuckRyder]

Not antisieze,

Might be leftover from a VC leak.

[My427stang]

Really good point on the O2 sensor, and although it is an average of all 4, the output it's helping the ECM make decisions for all 8 which adds to potential outliers.

I'd like to see the Platinum tip go away, maybe a heat range cooler, then maybe fatten it up a bit

I am not convinced the compression is what it is yet, based on behavior, timing requirements and cranking compression, but 2 out of three of those could also be caused by a few lean holes, so worth a shot

[DuckRyder]

Also:

I ran a dial indicator on #1 intake and am getting 29 degrees for IVO, this should mean that a 280 degree cam is at a ~110ICL.

[blykins]

I'd make sure it's not oil. 

Colder plug would be an easy check.  Throw some 124's in there, or some AR33's or something like that. 

Timing mark is showing that it wants more advance, but you probably have it pretty late due to it pinging.

[DuckRyder]

Ok;

I cleaned the treads for the plugs, installed 124s. I'm pretty sure it was from a VC leak it hasn't burned any oil that i can tell from the dipstick, but it only has about 1100 miles on it too.

I set the target AF to 13.0 at idle and cruise and 12 at WOT - Let me know if that sounds good or not.

I got another compression tester and did it will only one plug out - i got 152 or so gauge is much smaller but between 150 and 155 which jives much more with calculator.

Ran out of time to recheck with my gauge.

I'll try to drive it some next week.

[Jim Comet]

This is what happened when I had too much lash. I now lash on the tight side. Jim

[blykins]

Well, incidents like that are outliers, not the norm, and most likely not related to lash.

[bluef100fe]

So I read through all this… cause I’ve been there and done similiar.. C8-H heads polished deburred smooth chambers with a mirror finish, also milled too far 66-67cc IIRC. My truck was 3900 lbs then, 390, 93 octane fuel, tried a few somewhat rowdy flat tappet cams.. Compression ratio was calculated around 10.6 flat top badger cast rebuilder piston 4 eyebrow about 6cc IIRC then after changing to trw forged with recut valve reliefs about 10cc dish. Felpro 1020 gaskets and zero deck clearance. Anyway first comp cam was advertised at 270/274 @ .020 very aggressive xt lobe profile 240/244 @0.050 and measured .600ish lift and degreed ICL 106/ LSA 110. It had 210 lbs cranking compression… was very timing sensitive… 34 degrees was it and it would pepper the plugs . Used a 160 thermostat, tightened the lash as tight as I dared. Went to AR 33 plugs… started with 45’s and they were probably glowing because the engine wanted to run on when shutting it down until I went to the colder plug. Ran a Holley 4779 back then.. adding some jet helped.. phenolic spacer because fuel boiling in bowls was another problem, flooding engine after taking a trip and parking for an hour… engine would be flooded and not wanna start. When I went to the Oregon Cam couple years later added 8 degrees on intake advertised duration and at 0.050 so 278 and 248 intake lobe, added 12 degrees advertised and at 0.050 to the exhaust… similiar lift and degreed cam to 108 ICL. Was still 110 LSA… that cam change along with a little more dish on the piston were the best changes I made to that engine. Dropped cranking compression down to 190 PSI without crazy tight lash. I then could run 16 initial and 38 total timing by 3200 rpm and not pepper the plugs. Anyway, long trip down memory lane for me here but that’s what took the engine from a temperamental slightly PITA to I drove it from Wisconsin to Kentucky and back twice to the big block ford bash drag races two years in a row and loved every minute of it lol.

[DuckRyder]

Thanks Cody its encouraging you were able to turn it into a less temperamental engine withhte cam change, also a i ran across some old videos of your truck on you tube this past week, thing hustles.

So for those still following (i do this for my notes too)

Holley Dual Sync Installed:

This has allowed the idle speed to decrease to around 850. This really helped the way the converter acts when putting in gear and the ability to have significant idle advance (at  least that's my guess as to why) smoothed the idle out quite a bit.

I still haven't actually driven it, maybe a dump run this weekend, so it remains to be seen if we helped the spark knock, at least now i can play with it from the dash and not have to whip the timing light and distributor wrench out every time.