Cylinder #4 NO COMPRESSION

[henbone08]

About a month ago i threw a P304 (miss fire cylinder #4) thought it might just need new plugs so I replaced them and she ran fine. Yesterday i did an oil change and afterwards she was idling weird, sounded and felt like it was missing. took it around the block and pulled back into my shop and threw another P304. Did a compression check and only had 51psi out of cylinder #4. Chances are my ringland went out, but what else could it be? Burnt valve? Im going to yard the motor out tonight and see whats wrong. my next questions is what would be best aftermarket pistons and rods? I want to replace everything with forged and then run a hi flow top mount and finally get an access port so I know im running a safe effecient tune. Any input would be awesome.

after this I plan on running 18g, 1000cc injectors, and ACT street cluthc. but thats going to come later I just need my car to be mobile again and reliable. I want to put in the best PISTONS and RODS for the best price. Je? let me know what you all think

Henry

 

[ZachTTLM]

Far as pistons CP, Manley or Je are all very great pistons for your application. Far as rods a set of Manley Turbo Tuff will take alot of abuse and hold up very well. Other options would be K1-Technologies or Eagle H Beam. I also recommend using ARP Headstuds while she is apart when you reassemble.

I based my suggestions off the impression that you are looking for quality parts on a budget.

 

[ZachTTLM]

Far as misfire, are you throwing codes for any other cylinders or just #4?

 

[HolyCrapItsFast]

Given the track record with these cars it is likely a ring landing. Could be a bent or burnt valve but that would mean other more serious problems IMO.

What is the power goal of the car. There is no need to get "The best" if you don't need it. Some eagle rods and CP or Wiesco or JE psitons would do nicely if your power gaols are under 500whp. Try to find pistons that are coated. The real key to a proper and reliable engine has more to do with the machine work and the oil clearances. What ever you do, have the block machined to match the psitons and have it torque plate bored and honed. Again you have to figure out what the car is going to be use for here. You need to clearance your bearings to fit the situation. Stock clearances for daily and modest street, and extra oil clearance for drag and autocross.

Unless you plan on running E85, 1000CC injectors are to big for use with a 18G or 20G. You would do fine with 850cc and you won't have idle issues.

 

[henbone08]

i plan on finising around 380hp. Thanks for the internal ideas. i just need to be able to get them in fast, i cant wait 2 weeks for shipping....who would have them in stock ready to ship? i have about 3K to spend. internals, access port, and im going to do a full timing kit (82k miles) might as well. I havent thrown any other codes and she actually runs alright for 75% blowby. I originally wanted 850cc i just figured if i wanted to bigger later i would be set up. i will go 850cc. I want to stay with a TMIC. so Im thinking 18g would be great and give me the power im looking for. im going to pull the motor tonight and see how she looks.

 

[HolyCrapItsFast]

Blouch 20GXT FTW... 18G spool and capable of over 400WHP

 

[ZachTTLM]

Couple days from my door to yours regular shipping..express shipping is also available...let me know what you decide on exactly and I will put together a price for you. Right now we are running end of the year sales.

 

[ZachTTLM]

+1 for what Holy said with the build, injectors, and Blouch 20GXT.

 

[henbone08]

OK so I've already ordered JE pistons, ARP studs, head gaskets, Walbro 255, full timing kit and COBB AP. I have some concerns and questions. Running the walbro on stock 565cc injectors ok? It looks like I was running to much boost with not enough fuel pinging the pistons to death. My OLD tuner put 22psi on my vf39 which is way out of effecientcy range. After I put on all of these mods and get a legit retune with my AP i shouldn't run into any problems. I plan on doing injectors, inlet and Hi flow top mount after I get her back on the road and driving to finish up my build. I just dont have the money for turbo and injectors right now. I just want to make sure after I fix it and get a LEGIT COBB tune I wont run into this again. Shes my DD and I love her. breaks my heart doing this tear down but Im excited for the future power gain

 

[henbone08]

another thing, If i went with the 20gxt could I still run a TMIC?

 

[henbone08]

Did you run 21psi with stock injectors and stock pump?

 

[Vermont]

Did you run 21psi with stock injectors and stock pump?

When I was running 21 psi on my vf48 on stock fuel pump and stock injectors I was around 97% IDC. The fuel pump alone dropped the IDC by a good 5-6%. I am currently running the DW850cc injectors and love them. Great injector and not that hard to tune for. Instead of the Blouch 20g you might wanna check out the Blouch Dom 1.5XT-R. Here is a side by side comparison of the Blouch 20g and the Dom 1.5 done by Top Speed tuning.
http://www.iwsti.com/forums/power-bragging/221968-topspeed-motorsports-dom-1-5-testing-complete.html

This is what convinced me to pick up my Dom 1.5.

 

[henbone08]

ill probably just run 18psi until i get the 20g and then upgrade injectors and hi flow TMIC. after that she should be tits. I just need her on the road again. Thanks for clearing things up for me. I just dont want to go boom again so anything I can do to prevent it helps my wallet