4g61t.org

I replaced the head gasket this last weekend. It was starting to leak coolant. Not bad for 170k miles though! While i had the head off, i decided to get the dremel out and clean up the areas around the the valves. As many of you know, the 4g15 chambers have lots of ridges and projections around the valves. These are a major impediment to air flow through the head. I only had one day off work to do the job, so i didnt get into pocket porting around the valve stems and ports,as these are the other area that needs attending to on the 4g15. I am thoroughly impressed with the results of the moderate porting i did however! A noticeable improvement throughout the entire rpm range. Seems to help most low to mid rpm which is where i suffered most due to cam timing. The torque curve is definately flatter!
On another note, i also had to change the front main seal which had less than 30k on it! WTF? I popped it out with my fingers! It came from autozone. I have had problems with autozones belts stretching. Hmmm. Or anyone think the unusual wear could be mechanical?

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http://members.cardomain.com/socrateez
04' Olds Alero
91' Colt GL hatchback
4g15 12valve 5spd.
4g37 TB, MAF & Injectors. 4g37 ECU
Ported & polished & custom CAI w/K&N filter
5* Cam retard, 7*Ignition advance
2-1/4" catback w/flowmaster muffler
89 GT brake and suspension swap
Lots of little s#@t

Glad to hear that your mild clean up porting did the trick. I myself did the same things but included port matching the gaskets for the whole in/out process. Much flatter curve with less "come-on" around 3000 RPM would indicate that the air/fuel mixing must have been improved below the 3000 RPM mark making the transition rather invisible except for the inherent mechanical attributes that still exist concerning the breathing range of a 4g15 12V setup. Front seal problem? I used a Fel-Pro on all my gaskets that weren't more or less dealer specific and haven't had a problem yet, but my mileage is just rolling over 124.000 KM's following the full bottom end refresh around 112,000 KM's. Did you have enough breakin lube or grease on the seal lip when you had it installed? Pitting on the mating surface? Just a thought (but I'm sure you thought of those already, having a part fall off in your hand tends to make one wonder that much more! )
Tim

I did all the port matching on a previous modding spree! The seal wasnt even seted in all the way. I dont know if it was installed that way, or if it squirmed forward. I really gotta find a 4g37 ECU now though. After the chamber port my idle is crappier than ever!
Anyone want to trade me one for a 4g61t ecu and harness?

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http://members.cardomain.com/socrateez
04' Olds Alero
91' Colt GL hatchback
4g15 12valve 5spd.
4g37 TB, MAF & Injectors. 4g37 ECU
Ported & polished & custom CAI w/K&N filter
5* Cam retard, 7*Ignition advance
2-1/4" catback w/flowmaster muffler
89 GT brake and suspension swap
Lots of little s#@t

Yep that problem with cheap oil seals is extremely common. I use Fel-Pro seals as well as they are the Mitsubishi OEM supplier AFAIK.

I'll trade you my 4g37 Ecu if you are interested .... 4g61t ECU and Harness in trade? It's a deal, if you are still interested!
Tim

Pm me with the details ....

Soc, happen to have some photos of that porting process? A VFAQ on that would REALLY make my day perfect! Nice work man!

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Got rabies?

Sorry, no pics. My cheesy webcam/picture taker just doesnt focus on anything closer than say 5 feet. does ayone have a good pic of the combustion chamber? I could do a write up and use the pic to point out areas of interest and such.

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http://members.cardomain.com/socrateez
04' Olds Alero
91' Colt GL hatchback
4g15 12valve 5spd.
4g37 TB, MAF & Injectors. 4g37 ECU
Ported & polished & custom CAI w/K&N filter
5* Cam retard, 7*Ignition advance
2-1/4" catback w/flowmaster muffler
89 GT brake and suspension swap
Lots of little s#@t

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2000 Mirage RPW coupe. Too many mods.

Cool! Thanx!

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http://members.cardomain.com/socrateez
04' Olds Alero
91' Colt GL hatchback
4g15 12valve 5spd.
4g37 TB, MAF & Injectors. 4g37 ECU
Ported & polished & custom CAI w/K&N filter
5* Cam retard, 7*Ignition advance
2-1/4" catback w/flowmaster muffler
89 GT brake and suspension swap
Lots of little s#@t

thats the fruit and banana head from my 93, but im sure its the same.

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2000 Mirage RPW coupe. Too many mods.

so do you have results of what you grinded down? i want to do this.

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2000 Mirage RPW coupe. Too many mods.