T-78 dyno results w/ ported motor
#51
Originally Posted by black93RX7
zkeller: what would be the impact of higher EGT's?
What do the rest of you guys have for cranking compression on your motors? and do you believe the statement by my builder that cranking compression does not matter?
if the motor is bad i want it done again but not by the same shop; but I also don;t want to pay for another rebuild because it was not done right the first time. anyway I'm ranting
thanks
Erik
Higher EGTs can melt stuff if they are high enough. Try to keep them below 1600 degrees F. When not running the trailing, EGT's will be higher. Turbos will spool quicker though.
He is full of it. Cranking compression should be around 90. Is it hard to start and flood easy? Is it harder to start once warmed up? I think the plug that is wet all the time is not from the injectors. I think it is due to the compression issue. Are you checking it with the poor-man's compression tester, (tester with the schraeder valve removed), or with the Mazda unit?
He's half right. The higher in the RPM range the inertia of the rotor spinning helps pull the seals outward.
#52
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Originally Posted by black93RX7
I was at fred's alot last week, that is where I did the compression test. I was origionally going to have fred do my motor but he was pretty busy and I wanted it on the road asap. Can 't wait to see your car once its on teh road is it the nice red 2nd gen?
By the way I think I found my oil leak. I took off the oil filler neck and there was no gasket between the neck and the block plus one of the bolts was stripped. This must be it, I targeted this area b/c I had placed a piece of cardboard under the neck and after a little driving it was soaked with oil. I will reseal it a see what happens.
one problem down.
next I will work on why the plugs are not burning the same and then the main issue of low cranking compression.
Chris you should pm me
By the way I think I found my oil leak. I took off the oil filler neck and there was no gasket between the neck and the block plus one of the bolts was stripped. This must be it, I targeted this area b/c I had placed a piece of cardboard under the neck and after a little driving it was soaked with oil. I will reseal it a see what happens.
one problem down.
next I will work on why the plugs are not burning the same and then the main issue of low cranking compression.
Chris you should pm me
#53
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zkeller: first off my turbo does spool pretty good for a T-78.
second: yes it is hard to start and floods all the time and it is even harder to start when it is warmed up, I am fouling plugs almost once a day. I am not even driving the car anymore b/c it costs to much to change the plugs all the time. This is even after I leaned out the fuel. On top of this the car stalls all the time until it is warmed up and even stalls sometimes when it is warm.
third: I am using the poor man's compression checker, mazda wanted 1.5 hr labour to check it
second: yes it is hard to start and floods all the time and it is even harder to start when it is warmed up, I am fouling plugs almost once a day. I am not even driving the car anymore b/c it costs to much to change the plugs all the time. This is even after I leaned out the fuel. On top of this the car stalls all the time until it is warmed up and even stalls sometimes when it is warm.
third: I am using the poor man's compression checker, mazda wanted 1.5 hr labour to check it
#54
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Originally Posted by black93RX7
1) Is cranking compression irrelevent compared to compression under boost as I have been told by the builder?????
Cranking compression, when done properly, is a good indication of engine condition.
3) According to the builder to help prevent detonation the car is not running off of trailing plugs.
What impact if any is this having on performance? I have been told none, since they are only used for emissions.
What impact if any is this having on performance? I have been told none, since they are only used for emissions.
Try this test...
Dyno with all spark plugs.
Dyno with just leadings.
See dyno graphs difference.
4) How are these hp numbers compared to others run on a mustang dyno?
-Ted
#55
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Originally Posted by black93RX7
jantore: The engine is a brand new rebuild with new rotor housings and seals. The car has only been on the road for a month. I have put at least 5000 miles on the new engine so it should be fully broken in.
![Frown](https://www.rx7club.com/images/smilies/frown.gif)
When I told the builder about the low compression he said that cranking compression does not matter only compression under fire. He said as long as each rotor is the same it doesn't matter.
I paid approx $3700 usd for the engine rebuild with all new parts (rotor housings, seals, dowell pins, street port) and I am only getting 60 psi in each rotor. I think I got screwed and all the builder tells me is cranking compression doesn't matter.
![Frown](https://www.rx7club.com/images/smilies/frown.gif)
What do the rest of you guys have for cranking compression on your motors? and do you believe the statement by my builder that cranking compression does not matter?
![Smilie](https://www.rx7club.com/images/smilies/smile.gif)
I believe your builder is shoveling you a lot of bull...
-Ted
#56
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Originally Posted by black93RX7
second: yes it is hard to start and floods all the time and it is even harder to start when it is warmed up, I am fouling plugs almost once a day. I am not even driving the car anymore b/c it costs to much to change the plugs all the time. This is even after I leaned out the fuel. On top of this the car stalls all the time until it is warmed up and even stalls sometimes when it is warm.
![Frown](https://www.rx7club.com/images/smilies/frown.gif)
It's either motor is bad, tuning is bad, or both...
![Frown](https://www.rx7club.com/images/smilies/frown.gif)
-Ted
#59
don't know if this has any relivancy but my tII is doing the same thing. When the car is turned off there is no oil leak however when I start driving the oil starts leaking from around the drivers side. I'm about to look and find out where it is comming from but I just put in an fc3s.org oil pedestal and it might be comming fromt there. Is it spraying underneath the car or on top? Mine doesn't spray up it just drips to the bottom, I guess not enough pressure but when I'm driving it hard it is a damn big leak.
#60
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Originally Posted by black93RX7
jantore: The engine is a brand new rebuild with new rotor housings and seals. The car has only been on the road for a month. I have put at least 5000 miles on the new engine so it should be fully broken in.
When I told the builder about the low compression he said that cranking compression does not matter only compression under fire. He said as long as each rotor is the same it doesn't matter.
I do not believe what he is saying. For example if my new engine is at 60 psi in each rotor while another new engine is at 90 psi cranking compression, under fire wouldn't my engine still have lower compression than the one with 90 psi
I paid approx $3700 usd for the engine rebuild with all new parts (rotor housings, seals, dowell pins, street port) and I am only getting 60 psi in each rotor. I think I got screwed and all the builder tells me is cranking compression doesn't matter.
CCarlisi: I was thinking the plugs not burning the same is either from insufficient spark or a bad primary injector. I was origionally told the stock primaries were flow tested but then the when I asked the builder about this problem he said they were only cleaned
zkeller: what would be the impact of higher EGT's?
What do the rest of you guys have for cranking compression on your motors? and do you believe the statement by my builder that cranking compression does not matter?
if the motor is bad i want it done again but not by the same shop; but I also don;t want to pay for another rebuild because it was not done right the first time. anyway I'm ranting
thanks
Erik
When I told the builder about the low compression he said that cranking compression does not matter only compression under fire. He said as long as each rotor is the same it doesn't matter.
I do not believe what he is saying. For example if my new engine is at 60 psi in each rotor while another new engine is at 90 psi cranking compression, under fire wouldn't my engine still have lower compression than the one with 90 psi
I paid approx $3700 usd for the engine rebuild with all new parts (rotor housings, seals, dowell pins, street port) and I am only getting 60 psi in each rotor. I think I got screwed and all the builder tells me is cranking compression doesn't matter.
CCarlisi: I was thinking the plugs not burning the same is either from insufficient spark or a bad primary injector. I was origionally told the stock primaries were flow tested but then the when I asked the builder about this problem he said they were only cleaned
zkeller: what would be the impact of higher EGT's?
What do the rest of you guys have for cranking compression on your motors? and do you believe the statement by my builder that cranking compression does not matter?
if the motor is bad i want it done again but not by the same shop; but I also don;t want to pay for another rebuild because it was not done right the first time. anyway I'm ranting
thanks
Erik
Oh and there is not much diffrence in hot or cold compression. Just alittel bit.
#61
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Originally Posted by black93RX7
I was at fred's alot last week, that is where I did the compression test. I was origionally going to have fred do my motor but he was pretty busy and I wanted it on the road asap. Can 't wait to see your car once its on teh road is it the nice red 2nd gen?
By the way I think I found my oil leak. I took off the oil filler neck and there was no gasket between the neck and the block plus one of the bolts was stripped. This must be it, I targeted this area b/c I had placed a piece of cardboard under the neck and after a little driving it was soaked with oil. I will reseal it a see what happens.
one problem down.
next I will work on why the plugs are not burning the same and then the main issue of low cranking compression.
Chris you should pm me
By the way I think I found my oil leak. I took off the oil filler neck and there was no gasket between the neck and the block plus one of the bolts was stripped. This must be it, I targeted this area b/c I had placed a piece of cardboard under the neck and after a little driving it was soaked with oil. I will reseal it a see what happens.
one problem down.
next I will work on why the plugs are not burning the same and then the main issue of low cranking compression.
Chris you should pm me
the car should not spitt oil up the filler neck, no mather what. it means that compression is blowing into the oil chamber, and that is not good. somthing is wrong with the engine. get it stripped at this freddy guys place, and send the bill to the guy who built the engine. Oh and was it trough a company and did u get a waranty?
#62
Who built the motor?
I would say you're being lied to, just given the facts I've read here.
If you choose to have the same shop rebuild it again I would be there in person with a video camera taking both video and still pictures of the tear down.
If you choose to have someone else pull the motor apart do the same thing, video and still photos. Make sure everything you paid for is there. ie) Dowel pins, new housings, etc. If this builder is willing to feed you the B.S they seem to be feeding you then you might find you didnt get what you paid for at all. Be thorough.
I would say you're being lied to, just given the facts I've read here.
If you choose to have the same shop rebuild it again I would be there in person with a video camera taking both video and still pictures of the tear down.
If you choose to have someone else pull the motor apart do the same thing, video and still photos. Make sure everything you paid for is there. ie) Dowel pins, new housings, etc. If this builder is willing to feed you the B.S they seem to be feeding you then you might find you didnt get what you paid for at all. Be thorough.
#64
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I found something interesting:
The pcv valve was blocked and oil was leaking from where the oil filler neck was connected to the block. I put the neck back on with gasket sealer and unblocked the pcv valve. No more oil leaks! I will check the plugs in the morning, but I think I might have a leaking primary injector. The idle is now fluctuating 200rpm constantly and the car stalls until it is warmed up. Could be due to the tuning? I am not sure. Or the injector? The injectors will be pulled right away to check for problems.
The car seems to be pulling a bit harder after fixing the pcv, I am putting on a 99 front end and a cold air intake in the next few days. I have been talking to the shop and they have been helpful. The plan is to deal with all the smaller issues and tuning over the next week and dyno the car again. If the car is still not running properly and things point to an engine problem it will be pulled and checked. I have a rebuilt tranny that needs to go in soon, if need be the engine will be pulled at the same time.
The pcv valve was blocked and oil was leaking from where the oil filler neck was connected to the block. I put the neck back on with gasket sealer and unblocked the pcv valve. No more oil leaks! I will check the plugs in the morning, but I think I might have a leaking primary injector. The idle is now fluctuating 200rpm constantly and the car stalls until it is warmed up. Could be due to the tuning? I am not sure. Or the injector? The injectors will be pulled right away to check for problems.
The car seems to be pulling a bit harder after fixing the pcv, I am putting on a 99 front end and a cold air intake in the next few days. I have been talking to the shop and they have been helpful. The plan is to deal with all the smaller issues and tuning over the next week and dyno the car again. If the car is still not running properly and things point to an engine problem it will be pulled and checked. I have a rebuilt tranny that needs to go in soon, if need be the engine will be pulled at the same time.
#65
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Originally Posted by black93RX7
I found something interesting:
The pcv valve was blocked and oil was leaking from where the oil filler neck was connected to the block. I put the neck back on with gasket sealer and unblocked the pcv valve. No more oil leaks! I will check the plugs in the morning, but I think I might have a leaking primary injector. The idle is now fluctuating 200rpm constantly and the car stalls until it is warmed up. Could be due to the tuning? I am not sure. Or the injector? The injectors will be pulled right away to check for problems.
The car seems to be pulling a bit harder after fixing the pcv, I am putting on a 99 front end and a cold air intake in the next few days. I have been talking to the shop and they have been helpful. The plan is to deal with all the smaller issues and tuning over the next week and dyno the car again. If the car is still not running properly and things point to an engine problem it will be pulled and checked. I have a rebuilt tranny that needs to go in soon, if need be the engine will be pulled at the same time.
The pcv valve was blocked and oil was leaking from where the oil filler neck was connected to the block. I put the neck back on with gasket sealer and unblocked the pcv valve. No more oil leaks! I will check the plugs in the morning, but I think I might have a leaking primary injector. The idle is now fluctuating 200rpm constantly and the car stalls until it is warmed up. Could be due to the tuning? I am not sure. Or the injector? The injectors will be pulled right away to check for problems.
The car seems to be pulling a bit harder after fixing the pcv, I am putting on a 99 front end and a cold air intake in the next few days. I have been talking to the shop and they have been helpful. The plan is to deal with all the smaller issues and tuning over the next week and dyno the car again. If the car is still not running properly and things point to an engine problem it will be pulled and checked. I have a rebuilt tranny that needs to go in soon, if need be the engine will be pulled at the same time.
Ok here goes again. 60 PSI of compression on crancking is not OK. It should read 90PSI + on cold crancking. U have a blow side seal or corner seal somwhere.
I would recomend that u don't drive the car before u have rebuilt the engine. I now it's a bitch. I did blow my engine just right after it was finished due to fuel cut. And it was a bitch but hey, lifes a bitch.
The thing with the pcv valve might be because it's blowing to much in the oil chamber.
once again, 60 psi of compression indicates that somthing is wrong with our engine. I would do a rebuild if mine was below 80 psi. But that's how i am.
Oh and the first engine i rebuilt had a compression of about 55 psi and it was two cracked apex seals.
So don't hassel any more with finding problems. Take the engine out and have it stripped. U will find all our problems there.
JT
#66
Originally Posted by black93RX7
I found something interesting:
The pcv valve was blocked and oil was leaking from where the oil filler neck was connected to the block. I put the neck back on with gasket sealer and unblocked the pcv valve. No more oil leaks! I will check the plugs in the morning, but I think I might have a leaking primary injector. The idle is now fluctuating 200rpm constantly and the car stalls until it is warmed up. Could be due to the tuning? I am not sure. Or the injector? The injectors will be pulled right away to check for problems.
The car seems to be pulling a bit harder after fixing the pcv, I am putting on a 99 front end and a cold air intake in the next few days. I have been talking to the shop and they have been helpful. The plan is to deal with all the smaller issues and tuning over the next week and dyno the car again. If the car is still not running properly and things point to an engine problem it will be pulled and checked. I have a rebuilt tranny that needs to go in soon, if need be the engine will be pulled at the same time.
The pcv valve was blocked and oil was leaking from where the oil filler neck was connected to the block. I put the neck back on with gasket sealer and unblocked the pcv valve. No more oil leaks! I will check the plugs in the morning, but I think I might have a leaking primary injector. The idle is now fluctuating 200rpm constantly and the car stalls until it is warmed up. Could be due to the tuning? I am not sure. Or the injector? The injectors will be pulled right away to check for problems.
The car seems to be pulling a bit harder after fixing the pcv, I am putting on a 99 front end and a cold air intake in the next few days. I have been talking to the shop and they have been helpful. The plan is to deal with all the smaller issues and tuning over the next week and dyno the car again. If the car is still not running properly and things point to an engine problem it will be pulled and checked. I have a rebuilt tranny that needs to go in soon, if need be the engine will be pulled at the same time.
#67
Be VERY carefull.
Your putting yourself in a dangerous situation.
As was mentioned 60psi cranking is NOT OK. So if you continue to drive the car and it finally goes boom and dies, the chances are very good the builder will not warranty the motor saying "well there's nothing I can do now YOU blew it up" You will have a hard time proving there was any fault by the builder if the engine internals are no longer intact.
I've seen this senario more than a few times.
Your putting yourself in a dangerous situation.
As was mentioned 60psi cranking is NOT OK. So if you continue to drive the car and it finally goes boom and dies, the chances are very good the builder will not warranty the motor saying "well there's nothing I can do now YOU blew it up" You will have a hard time proving there was any fault by the builder if the engine internals are no longer intact.
I've seen this senario more than a few times.
#68
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I am really curious, who this builder is..
Obviously he did a shotty job and basically lying to cover his ***.
Black93rx7, why are you protecting this builder??
it is possible this same builder has screwwed others.
and if you say who it is. IT can confirm all your suspicions..
Obviously he did a shotty job and basically lying to cover his ***.
Black93rx7, why are you protecting this builder??
it is possible this same builder has screwwed others.
and if you say who it is. IT can confirm all your suspicions..
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