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Discussion Starter #1 (Edited)
Yep you read right. That's the combination I came up with after hours of research. I received a set of 40 over 4g63 pistons from a friend of mine. After inspecting and comparing the FE pistons with the 4g63 pistons you can see the compression height is a bit off, not by much. I was planing on using stock rods, but after some thought, I decided to upgrade for lighter rods and high rpm. The srt rods are 1.16mm taller than our stock rods which brings the 4g63 pistons back flush with the deck.The srt 4 rod big end is slightly smaller than the FE rods big end. My crank was under cut due to sitting for years and moisture got to the crank. that brought the measurement back to almost even with the stock rods with std size srt rod bearings. They also sell extra clearance bearining for the srt rods. When I get the bearings in, I will check the oil clearance and give you guys an update. For the head I'm using BLOX b18 valve spring. The Blox springs inner and outer are the same height. So no need to use any of your stock springs. I did a little port n polish to the ports while I had the head apart. And now for the pics.



difference between pistons




BLOX VS STOCK


H22 EX Manifold gasket and FE flange


stock pistons and rod on scale



eagle rod and piston= 300 grams lighter



head


q45 tb


On top of each other
 

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Interesting.........
 

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I just did some research and found that SRT4 rods are 5.945" or 151mm. Stock FE3 rods are 150mm
4G63 Pistons apparently have a compression height of 1.37" or 34.8mm putting your pistons 0.2mm below deck.

3SGTE pistons might have been a better choice at 35.0mm compression height...

There is not much in it though, I am always a fan of keeping the original combustion chamber shape as close to factory as possible to keep detonation under control.

So changing to 3SGTE pistons over 4G63s isnt going to make much difference as theyre both going to have different shapes over stock.

it'll be interesting to see how it goes
 

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Discussion Starter #4 (Edited)
I'm going assemble the engine during the week. I ordered 1 set of standard rod bearing from a local parts store so I can check the clearance on the rod. In the end I will be using CB1813H or HX bearings depending on what clearance I end up with. So I still have to do the ring end gaps. by the way what is every one using. I normally have my 2nd ring gap larger than my top ring. I'll be using .017 for the top and .020 for the 2nd ring.
I also have to check crank end play. Take it all apart and have it all balance. The machine shop is charging $250 for the balance. That is without any mallory metal. I should not need any because the rod and piston combo are lighter than stock.
 

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Thats my setup, but without the rods.

To get the comp ratio and deck height better, my head and block were both decked.
 

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Sorry to detract slightly from topic but what about using 4G63 rods as well? I don't have the two in front of me (fe vs 4g63 rods) so not sure if it will work with the stock crank.

OP > What is the width of the rod where the gudgeon pin (wrist pin for you us guys) sits? also what pin will you be using here? from SRT-4 stock or from what that 4G63 piston would normally require?

Really interested to see your progress on this one.

PS: Cam22 were you using 4G63 pistons on stock rods? What compression in the end after decking? Over sized valves at all?

Cheers
 

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Discussion Starter #7
Here are the stats on the rods.
Carrillo DG-SRT4>-65945H- - Carrillo Pro-H Straight H-Beam Connecting Rods - Overview - SummitRacing.com

I drop the rods off to the machine shop Friday, so it will be a few days before I hear anything. The srt4 rods wont fit as they are, the big end will have to be bored to match our stock bore which I believe is 2.126. The srt rods need to be bored .040 over which is .020 on the to and .020 on the bottom cap. Then they will be the same bore as stock. The width is also very close . a lot closer than any other rods I have looked at. Regarding the piston pin. Just use the pin for the pistons that it comes with. The 4g63 big end is way too small and the width of the rod is also too small.
 

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Stock rods with those pistions. Comp Ratio was 7.6-1 before decking. 8-1 after.

Standard valves, worked head and cams with aftermarket valve springs.

Car ran for 4 years with a rev limit set at 8000rpm. Crank snapped 6 months ago.
New standard crank in and running strong still.
 

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Discussion Starter #10 (Edited)
Stock rods with those pistions. Comp Ratio was 7.6-1 before decking. 8-1 after.

Standard valves, worked head and cams with aftermarket valve springs.

Car ran for 4 years with a rev limit set at 8000rpm. Crank snapped 6 months ago.
New standard crank in and running strong still.
My plan is to run e85 and 8000rpm like your doing. What head gasket are you using and how much boost are you pushing. Did you have your engine balance when you did your build?

Can you also post a link to the clutch your using.
 

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ACL headgasket (identical to stock one) and stock headbolts. I have never blown a headgasket but others have.

Boost 24psi min, average 28psi and the occasional 35psi. All on Pump gas 98 RON.

Clutch is a solid centre 5 puk ceramic with a resprung rx7 pressure plate (looks like a normal plate).

Engine was never balanced, forgot at the time.
 

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Good luck with everything. Let me know how it comes together. Should make for a fun car,you rode in mine you know its fun,lol.
 

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ACL headgasket (identical to stock one) and stock headbolts. I have never blown a headgasket but others have.

Boost 24psi min, average 28psi and the occasional 35psi. All on Pump gas 98 RON.

Clutch is a solid centre 5 puk ceramic with a resprung rx7 pressure plate (looks like a normal plate).

Engine was never balanced, forgot at the time.
so you said a RX7 pressure plate fits onto the FE flywheel? correct? do you need to drill any holes to slot the pressure plate into the flywheel? and how much torque can or is this clutch set up able to handle without slipping?
 

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Discussion Starter #15 (Edited)
I would like to get a cluth capable of holding 500ftlb with sprung center. Any ideas.
Just spoke to the machine shop. He quoted me $300 for zero decking and balancing. Sounds right.
 

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Stock rods with those pistons. Comp Ratio was 7.6-1 before decking. 8-1 after.

This is cam22t's comp ratio using evo pistons, could any body tell me, what the comp ratio would be using 3s pistons and stock rods, without decking...

I want to see if its possible to use 12.0:1 3s wiseco pistons, with very low boost, I think if the comp ratio ends up to be somewhere around 10.5:1 its doable.
 

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Stock rods with those pistons. Comp Ratio was 7.6-1 before decking. 8-1 after.

This is cam22t's comp ratio using evo pistons, could any body tell me, what the comp ratio would be using 3s pistons and stock rods, without decking...

I want to see if its possible to use 12.0:1 3s wiseco pistons, with very low boost, I think if the comp ratio ends up to be somewhere around 10.5:1 its doable.
I could get those wiseco pistons brand new for cheap ($300 already in Costa Rica), thats why I am considering on buy in them, but if its more than 10.5:1 I think its too much, I might sound stupid, but to me if cam22t had evo pistons which are 35mm, and the regular comp ratio is 9.0:1 and came up to be 7.6:1 before decking, than 3s pistons 35mm aswell (not 100% sure), 12.0:1 on the fe3n would be somewhere around 10.6:1, is that stupid? or am I close? I just want to know cause even though they are cheap I do not want to spend any moeny iif they are not going to work.

Any reply would be appreciated.;)
(even if its to say "yes you are stupid")
 

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I'm going assemble the engine during the week. I ordered 1 set of standard rod bearing from a local parts store so I can check the clearance on the rod. In the end I will be using CB1813H or HX bearings depending on what clearance I end up with. So I still have to do the ring end gaps. by the way what is every one using. I normally have my 2nd ring gap larger than my top ring. I'll be using .017 for the top and .020 for the 2nd ring.
I also have to check crank end play. Take it all apart and have it all balance. The machine shop is charging $250 for the balance. That is without any mallory metal. I should not need any because the rod and piston combo are lighter than stock.
hello,its been too long,but i need some info on that.I didnt dissamble my FE3 yet,but some guy is offering some Wiseco pistons for very very good price,would they work with stock rods?what comp ratio i would have?i cant get any SRT rods in my country,so would consider only pistons option,thanks in advance
 
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