Build Advice for my EJ25 Frankinstien Motor....
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This is a discussion on Build Advice for my EJ25 Frankinstien Motor.... within the Engine Modifications forums, part of the Tech & Modifying & General Repairs category; I recently spun a rod bearing in my frankinstien ej25 blcok with ej20 heads. Machine shop says it was most ...

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    Registered User ronzonothebugeye's Avatar
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    Red face Build Advice for my EJ25 Frankinstien Motor....

    I recently spun a rod bearing in my frankinstien ej25 blcok with ej20 heads. Machine shop says it was most likely due to lack of oil preasure. I want to build a street motor that can handle between 330hp-390hp. My old setup consisted of usdm sti cast stock sized pistons, ej20 stock rods, and a ej25 n/a crank. The ej20 heads are stock, I also ran the ej25 stock n/a oil pump, and stock ej25 head gasket and head studs. I am running a vf48 with a larger compressor wheel, 3 inch catless down pipe, perrin dual pipe exhaust, uppipe, turbo xs top mount intercooler, perrin intake, hks air filter, and 750cc injectors. I had it pro tunes at 18psi.

    I need some advice on my next build, I plan on running a set of STI rods, acl main bearings, clevite rod bearings. One size over usdm STI pistons, 2011 sti oil pump 11mm, stock head gaskets, arp head studs and stock EJ20 heads. My question is, will that set up handle 350-390hp? also the machine shop says my crank can be turned, but my question is, will it be able to withstand what I am looking for, or could it fail because its been turned, I get mixed opinions on that. Can cast sti pistons and rods handle what I'm looking for? The car is my daily driver...

    Any opinions or suggestions would be greatly appricaited! thank you!
    LS stocker to a VTEC rocker!

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    Master Baiter EJ257's Avatar
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    You have arguably the worst gas in the country; the last thing you want is the compression ratio you had with your last hybrid build. You have a few options: thicker headgasket (wrong way to do it), low compression pistons (wrong way to do it), or get the heads worked over to match the combustion chamber of the 2.5L heads (proper way to do it).
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    Registered User ronzonothebugeye's Avatar
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    Quote Originally Posted by EJ257 View Post
    You have arguably the worst gas in the country; the last thing you want is the compression ratio you had with your last hybrid build. You have a few options: thicker headgasket (wrong way to do it), low compression pistons (wrong way to do it), or get the heads worked over to match the combustion chamber of the 2.5L heads (proper way to do it).
    I had no idea that San Diego had some of the worst rated gas in the country. I do run a wideband, that should give some type of a blanket of safety... As far as running a thicker head gasket, that may be a great option, I've ran a similar setup on a 22rte Toyota motor, I ran a 3mm hks head gasket on 27lbs of boost on a t3t4. I do have a question though,(I know all motors have there strengths and weaknesses), but I have a number of friends that run 10.5 to 1 compression on b series Honda motors(which is Farley high compression) with no problems.. Does a ej25 with ej20 heads, motor really need to have the compression dropped that much to run sufficient? I'm sure there's a lot of factors, like a sleeved block or forged internals.... I appreciate the advice.
    LS stocker to a VTEC rocker!

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    zax
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    Quote Originally Posted by EJ257 View Post
    You have arguably the worst gas in the country; the last thing you want is the compression ratio you had with your last hybrid build. You have a few options: thicker headgasket (wrong way to do it), low compression pistons (wrong way to do it), or get the heads worked over to match the combustion chamber of the 2.5L heads (proper way to do it).
    I could not agree with this more.

    However, I seem to recall that Ray did it the [wrong way] and his Hybrid is still ticking along.
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