compresssion on high comp engine messed up

[maytag]

Not to be too critical of the writer, but it seems like you are writing using my kids text messaging shortcuts for words which us older folks are having a hard time deciphering. If you could use distinct clear sentances with at least some punctuation, that might help. If its a language thing then perhaps use one of those on-line free translation programs..... Then I would work on the chronological logic of your problem and steps taken to correct the problems. The overall description that I can manage so far is that you have unequal cylinder pressure after a rebuild. Lets start with what you did on the rebuild, then progress to how long you drove it before you had issues with compression and then what steps you have taken to analyze and fix the issues....We are here to support you, but its really hard to follow your post.

Well stated. I hope no offense is taken, because you said that very well.

I would like to emphasize again that until the head bolts are repaired, it is foolish to chase compression issues.
the broken head-bolts are ABSOLUTELY RELATED to the compression in each cylinder.

[DRHSMITH]

ok maytag im triyng to say this as simply as possible the broken bolts happened when i put the head back on ( last saturday ) the compression has been messed up for last 2 years. so the head bolts have nothing to do with the compression issue i do not know how to mkae this more clear . so with correct timing and seemingly great cylinder walls my ocmpression is all over the map , once agina before the head bolts snapped, i going to pull the block and re ring the engine becasue i leak tested the cylinder head when it was out so issue has to be in the block what could casue the rings to go so soon not even 9 thousnad kilometers on this engine , no point in doing the rings if something has casuedd them to fail prematurely ive posted to see if anyone has an idea or has seen this issue before so i can know anytinhg else i must look for or replace when i have the block out to re ring and fix head bolts

[DRHSMITH]

if m y compression was off with 2 snapped bolts i would not be in a forum asking why it wont seat correctly, the compression loss casued me to pull the head in the first place, along the way found that the massive ports i had done had not been gasket matched and the tappet issue , as well as porting out stock exhaust manifold more , the car runs very differently now it is fast but still not near when the engine had originally broken in , being the compression is so messed up. Car has a lot of torque low end and haf way through mid range after that car does not seem to push much horsepower at all ,
it seems as though half on the pedal and fulll are basically the same , the linkage does open throttle plates correctly and equally and the carbs are weber 44"s with 32 venturis

so right now even thogh head botls are broken car holds compression at previous values and runs better then it has last 2 years for certain , but with seemingly no damage to cylinder walls and less then 9 thousand kilos on the engine why would my rings fail so badly?

timign is correctly lined up on all marks, is there anyway that with high preformance engine setting different timing is nessesary, when i was younger i had set timing incorrectly a couple of times car ran like garbage, the fact that lower range and idle is so good makes me believe that the timing is correct but then what would account for the throttle not being active past half pedal ?

[DRHSMITH]

sry for not being clear on previous posts i own a heating and refridgeration company and working outsiode in the heat wave doing 14 hour days frys my brain so ive worte mid day on break to hopefully get message across with more clarity

[narfire]

I have seen broken rings shown to me from the instalation not going well and also the ridge on the cylinder not being honed.

[maytag]

I have seen broken rings shown to me from the instalation not going well and also the ridge on the cylinder not being honed.

me too. But they show-up with scoring on the cylinder walls very quickly. He says the cylinder walls are "great".

DRHSMITH:
so I take it the motor is assembled right now, right? Please do a leakdown test. If you don't know how to do that, let us know, we can help you. This will identify whether you have a problem of static compression (rings or valves) or with dynamic compression (cam-timing, valve/cam-clearances)

we can further narrow-down from there.

But I will say it again, in a different way: broken head bolts will not allow you to accurately trouble-shoot compression problems. They need to be fixed before you start going too far down the road. Even if that is not the original problem, you will never know you've fixed the original problem if your head bolts are broken-off in the block.

[DRHSMITH]

ok ill say again i pulled the head all valves seat correctly used an air pressure manifold tester and pumped 200 psi to each port in seated position with cam lobes not in contact, the head bolt issue happened recently and is not the stem of the compression issue at all all previous values before head was pulled were restored ,other then cylinder 1 which by adjusting tappet went up in compression 16 pounds, i pulled the head to inspect it and do a little more work to it and i pull it every once and a while to clean it anyways

even though compression is off would it explain that a 10 or more degree drop in outside temperature over doubles the cars runnning horsepower i have 3 snowmobiles and when air is colder the molecules are closer together they run a little better but 10 or more degrees to have such an astounding difference doesnt make sense to me , for example today is around 35 degreess car has no horsepower at all but in say october in temps below 12 degrees the car is insanely different last november raced my friends bwm 528 and destroyed it but in 25 degree plus weather i couldnt beat a geo metro likely
30 someodd degrees at 3000 rpm climbing a hill wether u step on the gas or hold half pedal car will barely accelerate below 12 one quarter pedal car will fly up the hill wihtout any sluggishness whatsoever

so im sure issue is in block is it possible that rings have seized up a bit or basically any other problem other then ring wear could cause this issue given that i can find no damage anywhere in cylinder walls
you coud see how this is driving me a bit insane last 2 years i avoid driving spider in hot weather cause its depressing then spring and fall i use the car every day

[DRHSMITH]

im dont rly think the unequal compression is reated to the way the car runs in hot as opposed to coder air temps so anyone who has seen this before please help me out i would really appreciate it , the car after its break in period ran exceptionally fast in hot weather so i dont know what to think

[maytag]

so you don't want to do a leak-down test?

you'd rather keep guessing?

I can't help ya then. You're gonna have to guess on yer own.

[TX82FIAT]

Do a leak down test. Your going to have to fix the head bolts no matter what you do. So... Pull the head and look at the gasket again. Measure the head for flatness and look for any other irregularities. I would look real hard at the porting. without re-reading your post i think you said something about a custom gasket and opening the head up significantly. You did not mention anything about what your exhaust looked like, white, blue, black? There are too many variable at this point to guess at a vlave clearance, valve leak, compression ring, coolant leak..... Just an absolute guess... but the uniformity of the decrease in compression leads makes me think the problem is related to flatness and gaskets/ports. Again, just a guess. do a leak down and you will also need to pull the head to fix the bolts.

[maytag]

I think he gave up on us.

He was posting 2 or 3 times a day, and even 5 times on Tuesday. And nothing since then.
I sense a frustration on his part that we weren't willing to overlook the obvious things first.
He is hoping to find a magic cure that not only solves the problems he knows about, but also all of the ones he either doesn't know about or isn't willing to acknowledge.

I think it's telling that the cylinder with the lowest compression numbers also had the valve-clearances way off. But without a leak-down test, it's just another guess.

I don't know why he's so resistant to a leak-down test though.

I'd sure like to help him figure it out.

[DRHSMITH]

ok i ruled out the head leaking when it was off using 200 psi heat exchanger pressure test tool tested every port with cam lobe not in contact only one cylinder was off on tappet tolerances and like i said i fixed that by finding one a 5 thou smaller on my parts car now cold tappet values are exact to spec from full engine manual, old head gasket showed no signs of leakage every one ive blown before would show fluid exchanging from ports or blown the ring aorund the cylinder seal , and forgot to mention i did check the head with a flat metal ruler from both diagonal ,vertial and horizontally across the head couldnt fit any size feeler guage through , how would i leak down test the block itself ? to rule out ignniton timing setting i have the distrubuter just barely turnable by hand trying differen t timings when retarded too much u get a bit of a ping when too far advanced car harldy runs so i play aorund wiht the inbetween , i find the car defenetly runs better slightly more advanced then the mark wiht ignition timing light lower rpm isnt as good but mid and higgher are improved, mkaes me think the distributer isnt advancing properly ive been trying for 2 weeks to call allison automotive but nvr get a response is there any other place to buy that perticualr distrubuterless iginition as the ease of set up seems a good candidate , wehter distributer is issue or not i want the electronic as the orgiinal is very outdated

[DRHSMITH]

and maytag all i wa sgetting at was the head bolt issue just recently happened when reassembling the engine the bolts had corrrectly seated before, i ran the car 5 and a half hrs last couple of days i just want to figure what else i need to do before pulling head/ engine as the compression started to drop way before the head had been pulled , the head gasket currrently seats fine no fluid loss or exchange and compression values are exactgly where they were before , and has anyone ever encountered this temperature issue where in cold car flys but runs slow in hot conditions and yes ive verified that water temp guage does work correctly and is showing an accurate value once car is warmed never strays too far from just a touch above 190 where car has always ran

[maytag]

Allison is the only place to buy that particular setup. If you email them, or even PM him on this forum (he is SOCAL Mark) he can get you squared-away. And I think it's a great choice. I'm going to do it too.

What is a lleakdown test? I'm glad you asked!
try this article for a better explanation then my own:
http://www.carcraft.com/techarticles/11 ... ewall.html

A standard compression test will show you the MAX cylinder pressure achieved as the motor revolves. But it will NOT show you how well that pressure is maintained. Knowing this can help differentiate between static compression issues and dynamic compression issues. This is understood because a cylinder which has low numbers on a standard compression test can have low numbers because the cams are opening valves too soon, or closing too late, and compression isn't there to begin with. OR they can be low because the pressure reaches a point at which it "blows-by" either a ring, or a seal, or a gasket. THIS will show-up on a leakdown.

So once you've done a leakdown correctly, you'll know if you are chasing a problem of "sealing" (rings, valves or gasket) or a problem of mistimed valve occurrence.

[maytag]

DRHSMITH:
hang in there dood. we'll keep trying to help ya. I know you are emailing me, I've seen 'em on my phone. But I think this is appropriate to keep on the forum, where everyone can benefit from the discussion. if that's cool?

You've mentioned several times the guy who built your motor for you. Your email even says he's a Fiat expert, who builds Fiat Spiders to beat Corvettes in the 1/4 mile! It sounds like he is some sort of pro? Do you mind if I ask who it is? Because the builder may be able to shed some light on this, particularly with things like your cam profiles, etc.

Additionally, It seems like we need to get our vernacular together on timing. You've mentioned adjusting your timing, but it sounds like you're describing your ignition timing, whereas I've been referring to cam timing. Do you have adjustable cam gears? and either way, have you confirmed your cam-timing marks line-up when your TDC mark does?

You're describing a significant change in performance based on ambient temperature (if I understand correctly). some of this is to be expected in any combustion motor. you've mentioned that it "doubles the horsepower". is that measured? or are you being descriptive, and maybe exaggerating a little? A well-misunderstood fact of combustion is that the cooler the intake charge, and the hotter the motor, the more efficient combustion will be (until your motor becomes hot enough it begins to detonate / ping ). This means higher cylinder pressure, more hp. But we're talking about as much as 10% increases, typically. not 100% increases.

I keep wanting to type guesses at you. there are so many things I keep thinking that could explain some symptoms. But really, they're just guesses 'til we have more info.

Can you do the leakdown test?