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11R 190 PTV issues , why and now what..

6K views 32 replies 16 participants last post by  4eyedfoxdriver 
#1 ·
I had a forged piston stock bottom end rebuilt. 56cc 11r 190 heads with Buddy custom cam. Valve is hitting on the exhaust side, builder said it stopped the motor , but looks like it was just catching the edge. The builder basically says it's not worth it for him to notch pistons, so he doesn't. He's going to recheck everything today, because I really thought this would fit. BTW this looks I'm not even sure a smaller cam would do the trick.


But now I have to figure out my next step.

Get new TW specific pistons, but they seem to be hard to find in a standard bore.

Take current pistons and get them notched

Try a different cam, I do have a E-cam

Get some heads to work with these pistons, though that kinda negates the benefits of the custom cam and really only leaves GT40x or AFR 165's..



Any input and links to some standard bore flat top Tw pistons would be appreciated.
 
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#6 ·
I thought the same thing about having plenty of clearance, especially with a purpose made stick. The guy is kinda old school with his thinking and had the attitude that there was no way these heads would work from the start, but he also does a lot of the circle track racers motors and not street 302 stuff. He comes highly recommended from some older guys but had never seen an 11r head. I was pretty insistent with him today, that's why he's going to recheck this evening. If he comes back with the same results , I'm confused and thinking about just having him assemble the short block and take it from there.
 
#10 ·
OK after talking with Buddy and the motor guy, and checking to verify the cam ended up dot to dot, the motor builder had an ahah moment. He say's he needs a vacation, and will verify it after bowling , but it will probably be good. So fingers crossed , as far as I'm concerned all's well that end's well. Last time things did not end well.....
 
#13 ·
I'm not writing the guy off just yet. I know he was going in to it thinking they weren't going to work and no other head with this size valve would. So he probably rushed through it, saw it it hit and said see I'm right. If he can't get it to work I'll deal with looking in to other options.
 
#16 ·
On the mock up motor, dot-to-dot was the alignment position that provided the proper positioning for the cam to match (as close as possible) the IO/IC/EO/EC events from my calcs. It was ordered that way on purpose. He also has the timing events required to match, should they want to verify. But unless his timing set is a major problem, it will come in pretty darn close to my verified numbers.
 
#20 ·
Umm. What size cam? I'm running a .60X lift cam with duration in the high 22X/low 23X on a stock 86 bottom end (true flat tops, mine are zero decked) and don't have issues with PTV. Same heads you have.

Edit: read the rest. Glad it looks like it's timed right now. Don't get strapped down by some "old school" mindset because 2.055 valves shouldn't be able to run whichever cam on a 302. That same mindset is why guys buy small heads and cam for "low end torque" that get their bumpers pulled off by cars that let that SOB breathe (with the right combination, of course).
 
#24 ·
Thanks and yeah, better safe than sorry I guess.

this is off topic and your prices are cheaper than a lot of other sites like ebay but man. Prices for parts sure have went up. Did all of this happen while the government bailouts were going on?

Afr I can understand. They use better parts in there stuff than they did years ago. (I know because I just replaced 16 black valve stem seals last week) But did tw and gt40s really get 5-600 bucks better?
 
#26 ·
I have just been out of the game for too long. I was actually about to sell my car until I started gaining interest again after helping someone with a micrsquirt turbo car.
 
#27 ·
this dot to dot stuff for this cam in question is becoming an issue, and it really shouldnt be. I verified the actual lobe openings and closings in a mock-up motor so I have actual verification what he would have in his hands, once he recieves it. The cam was not dropshipped. I provide those timing events at .050 lobe lift, but I also provide additional noting indicating where my timing set was aligned to acheive those .050 numbers. This particular cam aligned properly to my calcs, and per the way it was ordered, when installed (on my timing set) at the zero point, the point where the crank keyway and the camshaft dowel are inline, dot-to-dot on most timing sets. Everyone is getting hung up on dot-to-dot without knowing any of the background.

very few people I deal with degree cams, and when they do, it is done incorrectly probably 1/2 of the time. And believe it or not a couple of reputable shops have been clueless on cam installs too. So, I go an extra step for them by indicating where it aligned on my mock up motor. It can be viewed as a starting point, an end all, or not used at all and simply use the .050 lobe lift openings and closings for proper degreeing. Often times even sending pics.

When you do this often, working with individuals and shops, you quickly realize that all is not perfect. I have been surprised several times, well actually the correct term would be dumbfounded, when talking with some of these places.

using all 4 timing events, allows block to block variances and geometry differences to be seen, as well as dampening dial indicator set-up alignment variances. Whereas using intake opening only or peak lift methods doesnt catch this, ANd can put you way off base with quickly, with substandard measurement techniques.

I have not seen timing sets' (0) point vary significantly in many years, and 1/2 degree out is not going to be enough to really throw things out of whack. What I do see vary is the advance and retard of the sets out there and many are not what you think. Often they are in +/- 8 degree increments and noted in their paperwork as +/- 4. So my intent is nearly always to spec the cam, during the ordering process, so it will come in at properly at dot to dot; and this is after accounting for lobe growth/shrinkage as well as lobe shift. And when this isnt possible, then the same timing set is used during the verification then sent with the cam.

so, when all is said and done, dot-to-dot is a very nebulous term, no argument there. But in this case , for this particular, it is far less nebulous than the comments are indicating.
 
#28 ·
I just installed my cam from FTI this past weekend. If you have a dial indicator and a degree wheel, you can do it. This was my first time and it's actually simpler than I originally thought.

Make sure your intake open/close and exhaust open/close match the card at .050, if they're off in one direction by the same amount, that's how much adjustment you need. Adjustable timing sets make it easy to see which tooth needs to be pointing at the "dot" on the cam gear to get the proper degree change.

An hour more of initial time during the cam install is worth it rather than wondering why your power falls off a cliff at 5500rpm when it's supposed to be shifted at 6500.

I had an old Trick Flow mass produced cam that was advanced 8 degrees more than it was supposed to be discovered upon disassembly at my builder's shop, installed "dot to dot". No wonder it died at 5k. More like not to dot.
 
#31 ·
I just installed my cam from FTI this past weekend. If you have a dial indicator and a degree wheel, you can do it. This was my first time and it's actually simpler than I originally thought....
Just as often, the installers will look straight at the timing events, notated as .050 lobe lift openings and closings, and then go right to peak lift and go .050 down from the peak lift point (opening side and closing side) and their numbers are not even close to the actual numbers, and with an unsymetrical lobe, may be as much as 4 degrees off. they will complain and say they have always aligned cams by the peak lift point. thats fine, but thats not what the degreeing points say with the cam they received.

So yes, you degreed it correctly to Ed's numbers and process and were rewarded with seeing your numbers match Ed's closely. and yes it is easy, and instructional too as you can see the events happening versus piston position and crank position

But I promise, if you sold cams, you would see all sorts of funky things that occur.

I had one cam that was installed by reputable shop (seriously) and told me that the degreeing points were not correct, and durations were all over the place, cylinder to cylinder, and the cam was junk. It was fine on my equipment and their numbers did not match mine. It turned out they were using larger diameter cam bearings in this aftermarket block, and the cam was actually rocking around as it was being degreed. I dont know why they didnt wonder why the cam went in so easily. I cant recall the final way they realized it, I think they put in a known good cam, and it did the same thing. Once sorted out, back with the original cam and correct cam bearings, this motor has surprised many people on this board as to its output.

MANY MANY times people try to keep the crank gear oriented in its normal position and rotate the crank to the position on the gear, placing the crank way out of alignment (possibly 60 deg out).

sometimes they align the crank and cam gears both pointing upwards.

One funky time, the cam gear wasnt fully seated. IT pushed the cam back just enough to the point that there was cross-talk from lobe to lobe on the same lifter, on multiple cylinders. the motor actually cranked and ran!! In their tuning, they determined the firing order had to be off. then they removed the covers and saw the valves going ape. Returned the seemingly junk cam, that, once again, degreed fine on my equipment (same as it did before it was sent, the first time). I played around with different scenarios and saw what happens if cam gear isnt fully seated. I cant believe it actually ran. Anyway, I got them to send me their timing set. I made sure it worked (and it required massaging), and sent it back.

Always check your cam gear and cam on the bench!!


Then there's the ones that insist they have a better position for the cam. These are the ones that automatically retard or advance on the crank gear without even looking at any degreeing numbers or process whatsoever. doesnt matter if the cam already has the proper relationship ground into the cam and was found to be correct on my equipment. These are also the same guys that automatically add 10 jets sizes to a carb becuase they have a race motor, becuase thats just how it is supposed to be.

Also there are the guys that say they have never degreed a cam that wasnt correct to the specs. dead give away, they havent degreed many, or any, cams. cams are rarely perfect, when degreed in the motor. they usually end up about off by some amount. this is due to set-up inaccuracies, and block geometry tolerances, etc. some manufacturers' cam cards provide the timing events from the lobe master, and these may not be what you see in your motor.

A custom will come with the numbers you should expect to see in your block, atleast within +/- 1.5 degrees, on the openings or closings. Your block will have different alignment, your measuring set-up will be different off etc etc. it will never be absolute perfection, but it will be close.

One time several years back, one of the cam venders was getting bad cores. the dowell pin holes werent straight. they scrapped them. there is no telling how many drop shipped cams had to be returned. there are times when a photo is worth 1000 words. This was one of them.

.......
 
#30 ·
Anyways...after the guy called me up over something like that, I would be going over that thing with a fine tooth and comb.

I would probably even take some oven cleaner to one of the cylinder walls just to see if he even really cleaned the block.
 
#32 ·
I was the guy turning the crank to match the A2 slot on the crank gear!!! Then after I took a day off from it, I came back thinking wow, did I make this harder than it was. Aligned the A2 tooth up with the dot, checked and rechecked, and it was spot on. I can definitely see how there is user error because I fell victim to it as well before I looked at it and common sense told me to advance it 2 degrees, won't hardly be visible with the naked eye and to use the appropriate keyway pointed at the dot on the cam gear.


Sent from my iPhone using Tapatalk
 
#33 ·
use the appropriate keyway pointed at the dot on the cam gear.
This is what he did. He said he had it dot to dot, but in the wrong keyway. His expectations were so high of a 2.05 head not clearing a stock piston that he rushed through that part so we could get on solving the problem. He apologized and was like, if every customer who brought me custom parts went together like these his life would be easier, but it's not what he expects.

Anyway picked the motor up today. So on to the next step....
 
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