FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: DuckRyder on October 18, 2024, 11:04:23 AM
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Background.
I'm trying to make my current combination as good as possible with respect to my desired behavior, before I order another cam, I feel like making it as good as possible allows me to give better information / input to the new cam.
My questions.
We are talking about a Crower "street roller" 280R - 280/288, 234/244. 581/.583. Specified clearance is .026/.028 I've already tight lashed it to .018/.018
Typically Hydraulic cams are advertised at .006, i assume (we know where that gets us) that solid cams are advertised at the specified lash? So by tight lashing it the durations are already longer? Lifts higher?
Is there a way to calculate this change?
What if we run hydraulic roller lifters. (zero lash)?
With respect to running hydraulic lifters if we look at differences in advertised and .050 durations we are at 46/44 on the solid roller, if we compare to the edelbrock 2220 hyd roller 53/51 (and it has more lift), comparing to a Howards with the same 280/288 but 227/235 with .572/.572 we get 53/53. There seems to be agreement that the Edlelbrock lobes are aggressive so that's going to make Crowers very aggressive no? Possibly so aggressive the Hyd lifters wont work? As previously mentioned Crane back in the day had issues with too aggressive of a lobe causing issues with the heavy FE valve train.
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Ok If youtube is to be believed i may have answered a couple of my own questions.
Seems the solid roller cam was probably rated at .020 (vs .006) so at a lash of .020 advertised should match.
But the other valve events are quoted at tappet lift (zero lash). Also the lobe lift times the rocker ratio = .5808 so the actual lift is less by the amount of lash....
Makes it difficult to compare the aggressiveness of the lobe.
We've already established that math isn't my thing, but is there a way to calculate the change in duration due to changes in lash?
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Back in the late '80s when the EFI 5.0s came out, I wanted to put a 351W EFI in my '86 GT. I was one of the first, if not the first to do that conversion with the hydraulic roller camshaft. I talked with the technical representative at Crane Cams who was in the process of making 10 custom roller camshafts with the small base circle for installing in the 289/302/351W blocks. We ordered 7 or those first 10 camshafts, and I installed one in my 351/376W. When asking if we could install SR lifters on the HR camshaft, he suggested .004" lash. I used the Ford Motorsports HR lifters, and that engine ran fine for about 20,000 miles before trashing a lifter wheel and needles ruined a cylinder wall and oil pump. I know that SR lifters have been used on an EMC engine HR camshaft with success, but going the opposite way with HR lifters on a SR camshaft would not be something I would advise. JMO, but not a good idea. Joe-JDC
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...but going the opposite way with HR lifters on a SR camshaft would not be something I would advise. JMO, but not a good idea. Joe-JDC
Same thing I advised the OP over email.
Any time you are trying to change the cam with swapping lifters one way or the other, the cam is not correct for the application.
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Acknowledged on both points. I was intentionally leaving out the "He said/He said" (no she's have said in this case) on purpose so we could perhaps have a dialogue.
If we discard the whole hydraulic lifter on a solid cam idea, what about calculating change in durations and particularly IVC events as a result of changes in lash? OR is it so inconsequential that it isn't worth it?
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You'd have to map it out with a degree wheel.
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Noted:
One last question and i promise i'll shut up at least about this.
How tight is too tight - iron heads and block. .012? .010?
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I wouldn’t have went as far as you’ve gone….
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Noted:
One last question and i promise i'll shut up at least about this.
How tight is too tight - iron heads and block. .012? .010?
Too tight is when the valves don't seal at a given temp based on expansion. In some cases, usually un-naturally aspirated, you need seat time on the exhaust to cool when EGTs get very high, can be an issue on Cummins with guys who won't drop a gear pulling hard. Too much duration, however you get it, is the issue, not the lash itself. However, think boosted diesel pulling a grade with a load, your truck would never get there.
What problem are you trying to solve? If it's octane tolerance, you can't get a whole lot more. If you want to see what more cam is like, just remember you are adding overlap too by tightening lash.
I will say this, plenty of us have a ton of cam experience with a combo like yours. If you want a modern custom cam, it will be better than this experiment will indicate.
Now, if you want to try a set of hyd rollers on the cam just to pave new roads LOL, I really see no reason a mild solid roller lash ramp would bother a set of hyd rollers, but you'd have to be ready if somehow noisy. Of course, I'd rather see you get the right cam. Going the other way solids on a hyd cam, can be rough on lifters
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I guess Im really not trying to fix a problem anymore, since i know what it need to do, but i do have one thing that's bugging me.
I do like to understand the why's. This is not me arguing or not listening to experienced parties, it's just me trying to wrap my head around stuff.
"The problem" is that 20 years ago my machine shop had to take more off the heads than desired, leaving them with small chambers which raised the compression a little over half point from where i wanted it. I shoulda bought another set of heads then, but hindsight is 20/20.
I guess the second "problem" is that I don't hate the cam, it is not right for the combo but it isn't bad wrong, it'd be easier if it was awful and we weren't old friends. I suspect it's leaving a lot of power on the table because i have to keep the timing very conservative. Perhaps it's worse than i think. It already has more power than traction though.
So - I need to start collecting parts to swap the cam and I need to decide if i want to replace the heads. Probably a set of 72cc heads would solve the timing problem and make room for a more conservative cam, at this point in my life i might like a slightly more conservative cam (not TOO conservative.)... any way, y'all probably don't even care about me rambling on.
Heres what i don't understand though (AKA is "bugging me"). If i run the current combination through wallace racings calculator (need to see if i have a copy of P Kelleys on the old toughbook and if they agree. - edit - I do have a copy it comes up as 8.254- ) i get this:
C8AE-H / Crower cam 110icl
Static compression ratio of 10.6:1.
Effective stroke is 3.16 inches.
Your dynamic compression ratio is 8.14:1 .
Your dynamic cranking pressure is 162.48 PSI.
Your effective boost compression ratio, reflecting static c.r., cam timing, altitude, and boost of 0 PSI is 7.96 :1.
V/P (Volume to Pressure Index) is 161
These are their notes:
Dynamic Cranking Pressure: (at 150 rpm starter rpm)
Note=> after 7 to 10 needle pulses on a hi-quality Compression Tester
The slower the cranking RPM, the lower the cranking psi
The faster the cranking RPM, the higher the cranking psi
The poorer the Piston Ring seal, the lower the cranking psi
The poorer the Valve Seat (and guide) seal, the lower the cranking psi
In addition, aluminum Blocks may show lower cranking psi
Also Engine should be between 140 F to 180 F temperature for Tests
The compression tester's needle should swing over to 90+ or more psi on the 1st Pulse
this indicates great Hone Job, Valve Guides, and Valve Job
I have WAY more than that - like 190-195 psi after 5 pulses, it is perhaps turning faster than 150 rpm, but still it is not even in the ballpark. (is their calculator that wrong or is something amiss in the engine?) also i guess if advertised isn't actually where the events are happening that throws the shooting match off.
I did degree it when i first put it in but i probably used the .050 events because that is what is on the cam card. (Did i mention i really need to start writing stuff down.)
Guess I need to break out the dial indicator and figure out if the ICL and IVC is where it is supposed to be and if not why not.
Guess I will set the valves back to recommended when I change the distributor. (Going to get the ECU controlling timing this is an attempt to improve the drive engagement and idle).
Edit again- Also, i did think that getting this combination as good as possible would be mutually beneficial in getting a better cam, you know -i have this, it acts like this. id like it to act like___. Maybe that's not useful information though. <shrug>
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It would help, if we knew the bore & stroke, deck clearance, ICL and head & piston cc or, how much you cut the C8-H's and piston number.
If things aren't to out of wack, you might be able to just retard the cam and put a thicker head gasket on and cure most of your problems.
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Something in the engine doesn’t match what you think is in there. Theory really goes down the tube when your actual results show something totally different.
Before you buy a cam, I’d try to nail down your exact compression ratio. You don’t want to get another cam that’s made for a specific ratio and then it behave the same way.
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Hi Frank,
It's a 445. 4.08 bore, 4.25 stroke, Mahle 930264480 (18cc Dish), .006 below deck, the heads are 65cc. (the dish, heads and deck were all measured.) it has 8554PT head gaskets.
The cam is already retarded which theoretically makes the IVC 70. it is a 110 LSA installed at 110 ICL
Also, Joe thanks for your feedback earlier.
Agreed Brent, is the cranking compression what makes you say this? Its way too high isn't it?
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On a cast iron factory head with a factory chamber, it's higher than what I would want to see. But there's also a flag that the numbers don't match. The cranking compression calculators aren't perfect, but they should be closer than 35-40 psi.
Everything on your engine is higher (static, dynamic, crank) than what I would want to see for an iron headed pump gas street engine.
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BTW, I get lower numbers when I calculate it. ~10.4 and ~8.0. It would be a hair less than that with a little crevice volume factored in.
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So i guess I am trying to solve a problem.
WHY is the cranking compression so high? I'm pretty sure of the static is in the 10.4-10.6:1 range maybe I'm a cc off or a a thousands or two due to piston rock (i did use a deck bridge), a little on the head gasket but not that much.
In fact just playing with the calculator I would have to have done something (else) stupid like advanced the cam 4 degrees instead of retarding (There are only 3 slots) AND the cam would have to have 10 degrees less actual duration on the intake lobe to even come close to 190 PSI cranking on the calculator.
I guess the other option is the compression gauge is garbage?
(https://www.rangerxlt.com/images/forums/vehicles/F100/Engine/Compression.jpeg)
When I get a chance to work on it I will map out the actual events for opening and closing at the valve, and redo the compression test. It'll be a while, i'm building a basement... :(
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So degreeing the cam can tell you what the lobe is really doing, in the end, you can do that in the truck. However ultimately, your compression ratio does not match the cam and fuel.
That cam at 106 is going to be too small for a 10.5:1 compression, or better put, the compression is too high for that cam.
At 110 ICL, IMO, you are right on the edge for a light car, stiff gear, good fuel, which could lead you to tighter lash as we talked about before. Other band aids would be slowing down the curve, running richer, etc. However I think you are out of runway on the lash, it won't hurt to try if you want, I run my Mustang at .014 cold, but there is only so much you can do.
If you were to rock that cam back another 4 degrees or so, using a 9 position gear, at 114 I bet it would knock the edge off, and making sure it isn't hot, lean and the curve is right, would do OK on fuel.
But, later cam timing will drop idle vacuum if that's a concern.
However, if I was chasing it. I'd chase curve, plugs, and mixture now as a band aid to avoid going inside. Then resolve that I need to swap cams at some point.
A slightly larger lobe at .006, with .050 to match use of the truck, then spread the centers to meet vacuum and drivability requirements. No more messing around and you can get to what you want. That being said, to get that cam, need to get a real compression number and then degree the cam when installed.
Now there is a curve ball, because you are backing into a cam with high compression, there likely will be trade offs. A 445 in a truck is usually not a 10.5 motor, we'd be closer to 9.75-10 for a cam to match use. In fact, my own is exactly that, 9.75 with a 280 adv lobe and it does fine. That likely means you'd have to accept it being alittle more rowdy than we'd normally do it, or if you have room to still have decent quench, try to drop compression a bit, maybe both.
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Here's some more exact numbers, regarding CR/DCR, for the info given, using a 8554 head gasket, of 12.7cc and 110 ICL, as well as a 1.11cc crevice volume:
CR of 10.28, DCR 7.89. 10.39 CR and 7.97 DCR w/o the crevice volume.
Depending on the real octane rating, that should be manageable. You can drop it a tenth with a .061 thick FT gasket.
If the ICL is installed to the cam card 106 ( ICL), that rises you to 8.16/8.24 with and w/o crevice vol.
But, if you might of advanced the cam, instead of retarding it 4° (102 ICL), that would put you up to 8.4/8.49
I think you should check the ICL and the IVC, to see where you actually are.
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The crevice volume is actually .7cc on that piston.
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A couple comments as I read back
1 - You do not need to add lash, .018 is not too tight. Too loose is hard on parts, but you could go to absolute zero and if heat didn't reduce it, it'd run fine. The only thing that makes it rough is if you have too much lash and it hits the lift ramp before the lash is taken up. Not enough hurts nothing
2 - If this is EFI, fatten it up, stoich is only a chemical reaction number, not what the engine needs to see. Play with it 1/2 a point fatter if you have to. You can be in the high 13s at cruise and play with enrichment and WOT numbers
3 - I feel like Brent said earlier, you either have some parts you didn't expect, the cam in wrong as you said, the high cranking compression seems wrong, but it's a calculator, tune what you have
4 - Finding IVO and IVC can be from the top of a rockers at zero lash and tell you a lot
5 - If you do have the ability to use a computer controlled distributor, use it and put in 14 initial, WOT at 38, set it linear max to 3000 rpm, add 8 to cruise
6 - If you have a Sniper and you do not have the latest Holley ECM and handheld update, full stop. I have had so many things seem untunable and when I update it, it magically works as advertised
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BTW, I get lower numbers when I calculate it. ~10.4 and ~8.0. It would be a hair less than that with a little crevice volume factored in.
X2
Also tunable numbers, made a smidge tougher by weight and gearing, but still doable if not, hot, lean or too quick of timing.
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A couple of notes...
In past discussions of crevice volume, I've made the point that it just depends on the piston. Could be very low, could be high, just depends on the design/shape of the piston. As the piston grows, it also changes.
Not trying to contradict anyone on changing the lash by a great amount, but in times past, where I've ordered cams for testing, etc., both Comp and Bullet have both told me what the "extremes" were on the lobes that I had chosen. It's usually about a .004" swing in each direction. The lash ramp varies from lobe to lobe, manufacturer to manufacturer.
Now, with that being said, guys have tried different things and have succeeded, but in this scenario, something isn't playing right in the overall combination. A ~10.4:1 compression ratio and a ~8:1 DCR (or hair under) will live just fine on pump gas. Something else is amiss. Ignition timing, cam wasn't degreed correctly, oil consumption causing detonation, plugs in the wrong range, etc.
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The tighter the lash, the shorter time for cool down between strokes for the valve heads. I recently had a camshaft that required .009" lash, and after about 20 dyno pulls, the intake valves started to tulip and closed off the lash completely. This was with 5/16" valve stems. Opened up the lash to .016" and did not have any further issues with the valves growing in length. Just my experience, but don't band-aid the problem, fix it. Joe-JDC
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Joe has an excellent point. IMHO, unless you're running a Pro Stock engine, lash should not be used as a tuning tool. There are a lot of hidden effects from going outside the specified range. Aside from heat rejection to the seat, you get into pretty crazy dynamics. I'm with the guys who are advising attention to the real issue with the parts combination.
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I don't agree at all that it should not be used as a tuning tool, in fact, I think it's a great thing and you just need to know what you are doing.
In fact, my 168K mile Cummins runs tight intake lash, very tight and has since I did it in 2015 with about 10k on it, but exhaust I run the low side of stock specs for cooling. It helped boost, noise and valve bridge wear common to these
My Mustang has run .014 since 2006 with solid flats.
A lash ramp is there to slowly accelerate the lifter to be able to go more vertical...starting where the manufacturer wants you to of course is no problem, but starting late means you hit the steep ramp without a transition. Starting early doesn't hurt mechanical operation (aside from extremes, like Joe and I both pointed out, but .006 isn't .018) and more importantly, lobe families have lash values based on that design, not based on specific duration, so it's really not a valve cooling issue when the manufacturer gives a recommendation, it's a mechanical recommendation.
Aside from unique dyno mule or power adder issues that drive up EGTs, I'd buy a .004 limit on the loose side, I'd actually don't go measurably looser at all, but I have never had a lobe, lifter or otherwise an issue from starting closer to the base circle
Now, I 100% believe that there is something else going on in this engine, probably cam timing related due to not being what it is supposed to be, or advanced too far, and I also don't think that lash reduction will fix it. However, tight lash is not a boogie man and, in many cases, can improve durability and allow some tuning.
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Ross - I should have put some more context into my comment. Playing with lash can get you some nice (subtle) benefits, but as you said, you must know what you are doing and where you are with your combo! Most of us with our street engines don't need that level of precision. When you see a typical solid valvetrain actually running, the dynamic lash ends up pretty far away from what you measured statically. It takes experience to understand what will work, and how far you can go. Most of us don't have that...
In the OP's case, there is stuff an order of magnitude more important going on. I'd say the jeweler's screwdriver can come out when you're done with the big tools.
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Ross - I should have put some more context into my comment. Playing with lash can get you some nice (subtle) benefits, but as you said, you must know what you are doing and where you are with your combo! Most of us with our street engines don't need that level of precision. When you see a typical solid valvetrain actually running, the dynamic lash ends up pretty far away from what you measured statically. It takes experience to understand what will work, and how far you can go. Most of us don't have that...
In the OP's case, there is stuff an order of magnitude more important going on. I'd say the jeweler's screwdriver can come out when you're done with the big tools.
Thanks for clarifying and I hope I didn't sound too challenging as well. I agree completely, small changes can be accomplished, but not the overall characteristic of the cam.
The neat thing is that IVO on this cam at .020 should be about 30 degrees BTDC, looking for an 8 degree error could be found with a dial indicator on the pushrod side at zero lash and be seen on a balancer...since he corrected his timing marks before, wouldn't have to do much more than pop a valve cover, get on the base circle, adjust to zero lash, and turn it clockwise until it reads .020. If it's nowhere near the 30 mark yet....it's wrong
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OK I appreciate all the input, plenty to consider.
I think I've reached the acceptance phase on changing the cam and will procure parts to change it to a hydraulic roller. I think i will likely change the heads too and i need to make that decision finally before the cam.
Even when this engine was a 390 it behaved similarly with this cam, it was very sensitive to octane and timing and really did not want more than 32 or 33 with a somewhat slow curve. It does not have vac advance. When it was built as a 390 i suspected the dcr was going to be a problem and considered retarding the cam then, Mayhem Bob (RIP Bob) talked me out of it because it did not seem like it should be that bad.
When i rebuilt it as a 445 Ross and I had a lot of discussion and we decided to retard the cam and run the 8554 gaskets instead of 1020 in an effort to improve the situation, he wanted me to change the cam then, and I should have, but time and money was an issue. (mostly time, i needed it running to move it to another state). I checked all the measurements deck, head and piston ccs, bearing clearances - everything. I just did not write any of it down. I know i checked the cam when i first put it in the 390, but i might not have when i did the 445.
Im pretty sure the static is right as we've calculated it (i get 10.5-10.6 depending on the numbers i use for the head gasket)., Brent is probably closer. The rotating assembly came from a reputable supplier and i went back and looked at the pictures an its all the right stuff. Plus it measured out as it should. The heads i CCed at between 65 and 66 i use 65 because the smallest chamber was 65.1cc, This jives with what the machine shop originally cc'ed them at (they told me 66). Again this is not me arguing, it's just me saying i don't see how the static could be that far off.
The cam - It also came from a reputable supplier way back it was sort of a last minute change in the build because this was at the time that everyone was using johnson lifters and all of a sudden no one could get them and Flat Tappets were wiping out right and left, Hydraulic Rollers for FEs were in their infancy - Crane made them but they were having trouble too. My original plan had been about 10.0:1 and a Crane 343801, i had debated the 290R but did not want it that rowdy. I also have the cam cards for a number of other cams i considered and calculated DCRs on - weird i have this kind of stuff but not clearances cam degrees and so forth, i had just crammed them in some of my books. Anyway - trip down memory lane.
Also Crower did confirm they use .020 as advertised on this cam.
Based on the feedback i will degree the cam in the truck, I really don't think I advanced it but will check. I'll also "rent" a compression tester when i do that and see if it agrees with mine. Because according the the calculators even that should not get this cam anywhere near 195psi cranking compression. As Brent said yes it's just a calculator but 30-40 PSI seems too far off.
Plugs and timing were mentioned. It currently has Autolite 45's, it has an MSD distributor currently with 12 degrees initial, a blue bushing and 1 light silver and 1 heavy silver spring.
I believe the target AF is set to 13.6 but will have to double check that,
Also i will get the Termiantor controlling the Timing and see if that changes anything.
I'm planning to change the cam, but need to figure out why it's acting the way it is.
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Can you show me a detailed picture of the insulator, threads, and ground strap of the plug?
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I can: Depending on internet speed give em a second.
(https://www.rangerxlt.com/images/forums/vehicles/F100/Engine/PP45a.jpeg)
(https://www.rangerxlt.com/images/forums/vehicles/F100/Engine/PP45b.jpeg)
(https://www.rangerxlt.com/images/forums/vehicles/F100/Engine/PP45c.jpeg)
(https://www.rangerxlt.com/images/forums/vehicles/F100/Engine/PP45d.jpeg)
(https://www.rangerxlt.com/images/forums/vehicles/F100/Engine/PP45e.jpeg)
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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 :o
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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.
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Is that oil on the threads or some kind of left over anti-seize?
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Not antisieze,
Might be leftover from a VC leak.
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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
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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.
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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.
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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.
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This is what happened when I had too much lash. I now lash on the tight side. Jim
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Well, incidents like that are outliers, not the norm, and most likely not related to lash.
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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.
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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.