as both our hardware and software gain higher performance it becomes more important to support our block. Mazda stopped at 215 rwhp. of course we think, wrongly, 400 rwhp is moderate. 600 is easy w the proper turbo, ports, and E85. you can visit 600 more often with the right mods.

one of the links in the chain is block integrity. (ONE bad link and the chain breaks)

our blocks are five plates bolted together. a common conclusion is to increase the clamp.

see: TENSION BOLT TECH

while there is nothing wrong w this, generally the most challenging forces are radial. increased clamp does close to nothing to help radial forces caused by knock.

a picture is worth....



i realize this isn't news to anyone who has built their motor but many have not. notice 2 thru bolts and a dowel pin. the black item is an OE thru bolt... 9.37 mm diameter. the top bolt is 10 mm and is the same diameter as the typical "stud kit" item. notice the huge gap between the bolt and the hole on both the 9.37 and 10 bolt. there is ZERO radial support for the housing, only axial. notice the OE dowel pin... approximately one thousandth clearance and major radial support.

unfortunately there are only two. they are the only support against radial force other than the aluminum rotor housings. being tool steel they don't often break but they do transfer force into their nesting place in the side irons. the pocket in the outer side irons is only 1/2 inch deep and is fragile cast iron.

consequently it is no accident that there are loads of used center irons available but zero front irons. (Mazda did reinforce the rear iron as it was the weak link in the FC.) further indignity, front irons are within a happy meal of $800 today.

front iron carnage because only one dowel pin to offset radial forces.

there is a fix. how about SIXTEEN dowel pins, actually Stud Dowels as they do both. same dowel pin thousandth clearance but also a 1/2 inch-- 12.7 mm stud.



i wasn't able to find a pic of all 16 but you get the idea.

a few years ago only the 1000 hp drag racing guys visited stud dowelville but w the advent of much faster spooling street friendly 80+ pound per minute turbos as well as 5 figure 2 rotor builds having a solid block is a much more attractive option to many.

another option is the one piece dowel pin. you also have the option of having both one piece dowels being solid as on my motor.


an external oil line, from the oil filter base to the front iron delivers the oil.

one piece dowel pins are currently available thru Lucky7.

i use REC for my machine work. i would be interested to learn of other shops offering this mod. one key consideration is the stud material and the recommended torque as it is possible to get too much clamp.
i engineered my external oil line. it eliminates one poorly engineered 90 degree turn for the oil flow. it is also important to source the FILTERED oil to the front bearing. only the FFE oil filter platform delivers filtered oil.


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First, important post. Thanks

Second, why do you say this? You're talking about the Full Function Engineering oil filter pedestal, right? I've not examined one myself but the FFE design does not seem significantly different or revolutionary, in terms of oil path or delivery, compared to pedestals available through others. Do I have something to learn, here?

 

FFE redesigned their pedestal so the ports tap into the oil after being filtered. this is very important if you are using the pedestal to supply oil to your turbo. initially i was using a pedestal that produced unfiltered oil to my front crank bearing. i now have an RX8 crank and new front stationary gear as a result.

i looked everywhere for a proper pedestal and found one in Australia. i sent it to an engine customer who i had done an external oil line for. afterwards, i happened to be talking to FFE and they said they had re-designed theirs with that in mind... so i am now running the FFE. 2 years, no problems. good on FFE. i couldn't find it on their site until i used search.

 

An old school rotary builder (he now does 2000hp LS motors) I used to work with helped me dowel a couple of tension bolt holes in key areas. We machined out the tension holes and even a bit of the front plate threads to fit the dowels in a nice fit, I want to say it was in two spots, and we used left over stock dowels. I'm only around 400whp, and really don't know how far I can push such a setup. Anyone have any opinions on this?