20B NA BP semi-PP ITBs
Glad I checked by for the new updates. Lots of cool stuff to look at!
44mm p-ports?? Those arent semi p-ports anymore.... that is full p-port! lol. Need to change the thread title- "P-port with bridge port primarys"
Oh and those stock oil coolers even with the trans cooler wont tolerate much abuse before getting hot. Start looking into some large setrabs when you get the chance.
Looks good though!
44mm p-ports?? Those arent semi p-ports anymore.... that is full p-port! lol. Need to change the thread title- "P-port with bridge port primarys"
Oh and those stock oil coolers even with the trans cooler wont tolerate much abuse before getting hot. Start looking into some large setrabs when you get the chance.
Looks good though!
Yeah I didnt think the stock coolers could do much for the 20B. But yes once its all up and running well, I will fit the biggest coolers possible before a track day.
Not semi indeed!! After speaking with Xtreme rotaries about my retarded ideas, I decided to go with an extend port primary and 44mm PP.
Not semi indeed!! After speaking with Xtreme rotaries about my retarded ideas, I decided to go with an extend port primary and 44mm PP.
Curious, why did you go with -8 oil cooler lines when the Fd virtually uses -10? It helps to have the extra oil volume with this larger engine since the 20b oil pump is the same as the Fd's.
Well the oil lines I measured were about 12mm ID, 1/2 inch, therefore -8.
The oil entry into the block is actually smaller, plus I had read on here that it has been done with -8 lines for exactly that reason.
The oil entry into the block is actually smaller, plus I had read on here that it has been done with -8 lines for exactly that reason.
40mm and 45mm.
And to help out my mate who made them, (and to help pay for the tools I had made), he is more than keen to make them for anyone.
All you need to do for individual use is to CAD up a base plate, have them water-cut and areldite them to the base of each trumpet.
If anyone is keen PM me!
Oh yeah and wait till you see them finished, for sexiness, Im going to sand the outside and paint them with 2pac clear!
And to help out my mate who made them, (and to help pay for the tools I had made), he is more than keen to make them for anyone.
All you need to do for individual use is to CAD up a base plate, have them water-cut and areldite them to the base of each trumpet.
If anyone is keen PM me!
Oh yeah and wait till you see them finished, for sexiness, Im going to sand the outside and paint them with 2pac clear!
Normal cruising down the street you won't have a cooling problem. Your still talking about an engine capable of 9k redline and it's power band in the stratosphere. Cooling is always an issue on 20b NA or turbo. The extra rotor and longer block heating things up should never be over looked.
Don't forget the 20b's original designed application. Those passages are smaller into the block because your dealing with an engine originally designed to move around a luxury car that's mated to an automatic transmission and a lower rpm red line. The oil system only needed to be adequate. That's why it has the same oil pump the 13b-rew has. The 20b engine in the Cosmo was never engineered to be anything serious on a track. You try to track a stock 20b Cosmo and your gonna burn up the engine plain and simple. The Fds oil cooling setup is far superior to the 20b Cosmos because in the Fd it had to be for what it was designed for. That's why it has the larger lines to move more oil. I promise you with what your building your engine UP to, you are eventually gonna have to upgrade that entire oil cooling system. Now there's nothing wrong with doing things in stages to get an experimental project up and running. That's usually how I do things myself
Well the engine has all the internal galleries modded by Xtreme rotaries. It also has the oil feeds split out of the remote filter into 2, one of which feeds the rear, one feeds the centre plate bearing on a T which also feeds the front plate.
So internally the bearing feeds are larger and the pump feed is larger, these mods are what Xtreme does to assist in a high revving 20B.
I don't know when dash 8 lines would become a restriction to the oil system though.
So internally the bearing feeds are larger and the pump feed is larger, these mods are what Xtreme does to assist in a high revving 20B.
I don't know when dash 8 lines would become a restriction to the oil system though.
The hard pipe on the fd vs the 20b is larger. Where I got the -10 measurement was on the fds rubber hose section to the oil coolers. I forget that your still using the 20b front cover. I used the fds so I could take advantange of it's larger ports. To me it just makes more since to use larger feed/supply lines before any T's in a hydraulic/oil lubrication system.
Some slow progress on the exhaust.
Just needs some tigging and should be sorted.
Ended up quite long, which is good, hopefully it will be somewhere close to what it will like!
It is very tight fitting all that **** in there!!

Just needs some tigging and should be sorted.
Ended up quite long, which is good, hopefully it will be somewhere close to what it will like!
It is very tight fitting all that **** in there!!

Where the runners connect to the header, are you making sure you have equal length pipes?
Also are you making sure the length is somewhere appropriate for tune on them? Collection length is pretty important for tuning the exhaust properly... along with collection point.
I am just asking cause I might have missed reading it already..
Beautiful work btw. You have a nice toolbox to work from. Helps make pretty, and accurate parts. Gotta love the CNC.
(Need to finagle buying one, one of these days LOL)
Also are you making sure the length is somewhere appropriate for tune on them? Collection length is pretty important for tuning the exhaust properly... along with collection point.
I am just asking cause I might have missed reading it already..
Beautiful work btw. You have a nice toolbox to work from. Helps make pretty, and accurate parts. Gotta love the CNC.
(Need to finagle buying one, one of these days LOL)
Yes they are equal length. Also proper tuning of a primary length can only really be done by trial on a dyno. These are as long as I could possibly fit under there, which would give me room to make them shorter.
There is no way to work out what will be perfect to suit the port configuration.
There is no way to work out what will be perfect to suit the port configuration.
Yes they are equal length. Also proper tuning of a primary length can only really be done by trial on a dyno. These are as long as I could possibly fit under there, which would give me room to make them shorter.
There is no way to work out what will be perfect to suit the port configuration.
There is no way to work out what will be perfect to suit the port configuration.

SOme of the racers I know (going un-named) made slip fit joints in the middle of thier exhaust system so they could change the tune length up to 2 feet. This enabled them to tune and re-tune and re-tune on the dyno for best power at the RPM they are building the motor for.
Once they have the length of the collector correct, they simply remove the tunable section, and make a solid section.
Of course they have to re-tune for best power each change. As the scavenging/supercharging gets better or worse as they go.
Yep, thats definately the way to do it. Pity doing NA right is such an effort!! I cant imagine I will go to that much effort, however if something really doesnt work with this setup, Ill look into exhaust tuning.






