Lowering compression...

[zappa]

I understand some guys are lowering their compression using Jim's heads.What are the advantages if any of going this route versus lower compression pistons?.It seems that since the pistons/connecting rods are somewhat weak in the 1MZ-FE it would make sense to solve the high compression problem (when S/C'd or T/C'd) while beafing up the lower end w/ forged pistons/c.r.'s.
Also is it true that supra pistons/rods can be used?Seems unlikely but I thought I read it somewhere(?).

[cdssolara]

I understand some guys are lowering their compression using Jim's heads.What are the advantages if any of going this route versus lower compression pistons?.It seems that since the pistons/connecting rods are somewhat weak in the 1MZ-FE it would make sense to solve the high compression problem (when S/C'd or T/C'd) while beafing up the lower end w/ forged pistons/c.r.'s.
Also is it true that supra pistons/rods can be used?Seems unlikely but I thought I read it somewhere(?).

If you're planning to run really high levels of boost, then it would be a really good idea to beef up the bottom end as you've suggested. Jim's heads are an option if you just want to be able to bump the boost a little. It's been found that even 5.5 to 6 psi of boost can cause the knock sensors to set off the Check Engine light and cause timing retard. The idea behind Jim's heads was to allow boost levels of 7-9 psi without risking this so much. In the case of us California people with our 91 octane premium gas, we can run 6 or 7 psi of boost without too much problem.

[shidosha01]

Another idea that my mechanic and I have in mind is lowering the compression by getting thicker head gaskets. Been waiting for two weeks now to get an answer and see if it can be me made.

About the Foreign Affair heads...

How much does it lower the compression? From a stock 10.5:1 to ???

[Jackass-Jeff]

The Supra pistons will only fit if they have the same bore and I dont think they do. I think you read Supra Injectors and mixed up injectors and pistons =]

[cdssolara]

About the Foreign Affair heads...

How much does it lower the compression? From a stock 10.5:1 to ???

I think Ericsol had his tested and they came out around 9.2 or 9.3:1.

[B_Master_Flash]

I didn't think they made lower compression pistons/rods for our engine...

[Jackass-Jeff]

I didn't think they made lower compression pistons/rods for our engine...

Jim@Foreign DID make them

[LifeguardSLE V6]

If you are a reader of Import Tuner, in 03 they did a build on a 1MZ, and they beefed up the internals. I only have one part of the build-up, but they did put in new heads and all to make some crazy power overall. If you can find the issues, that should give some insight.

[shidosha01]

If you are a reader of Import Tuner, in 03 they did a build on a 1MZ, and they beefed up the internals. I only have one part of the build-up, but they did put in new heads and all to make some crazy power overall. If you can find the issues, that should give some insight.

I heard about that. Do you remember what month it was last year that had that article?

[LifeguardSLE V6]

okay, it was Turbo magazine, and the build up ran through the summer, I don't know the exact months, but it was between May-October probably. I remember putting a post on here about it, and one of the biggest problems with new heads comes from the fact that stock heads have oil squirters built in for lubrication, so new heads might not provide enough lube and could be a serious problem.

[JoeB]

Any chance anyone can come up with this? I'd really like to see that article. I'm considering doing this andthis seems like a great way to get advice from the experts. I called Import Tuner and they said there is no way for them to tell me when the article ran, probably will be the same with Turbo Magazine. I'd be happy to buy past issues and tell you what it says . -JoeB

[cdssolara]

Any chance anyone can come up with this? I'd really like to see that article. I'm considering doing this andthis seems like a great way to get advice from the experts. I called Import Tuner and they said there is no way for them to tell me when the article ran, probably will be the same with Turbo Magazine. I'd be happy to buy past issues and tell you what it says . -JoeB

Joe,

It was a series of articles, and I'm pretty sure they were in Turbo Magazine. I believe that the articles were about a 1MZFE engine that was going to be swapped into an MR2. They ran last summer and fall.