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i must say, i had never heard of anyone reversing the primary and secondary ports...interesting if nothing more.
and Peejay, im interested in this magic manifold you speak of, an we see it :)? alo, you said not to use staged throttle, but to idle on all 4 ports instead for better driveablity? if so then, thanks for saving me alot of time setting up a staged throttle itb set up (what i was thinking about doing). it's great to see people with real world experience sharing their knowledge with us guys that are less educated with real world experience. i appreciate your input. by the way Peejay, what apex seals do you use? im thinking about atkins cryo seals but am unsure. just thought i would ask :) |
I used those with great success, and they're what are going into this engine a well. I had problems with the seal springs wearing heavily on the underside, but this may have been a dust intrusion issue. Very housing-friendly, after 50-60k of use and abuse the rotor housings looked fine.
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Originally Posted by rx7freak13v
(Post 11149493)
i must say, i had never heard of anyone reversing the primary and secondary ports...interesting if nothing more.
and Peejay, im interested in this magic manifold you speak of, an we see it :)? alo, you said not to use staged throttle, but to idle on all 4 ports instead for better driveablity? if so then, thanks for saving me alot of time setting up a staged throttle itb set up (what i was thinking about doing). it's great to see people with real world experience sharing their knowledge with us guys that are less educated with real world experience. i appreciate your input. by the way Peejay, what apex seals do you use? im thinking about atkins cryo seals but am unsure. just thought i would ask :) you build from the centreplate out with the apex seal wedge piece away from your angle cut housing. and keep the bridge as ( now ) secondaries with short runners ( which where primaries ) .. but of course you need a staged TB to be able to have primaries ..and to maximise low down air speeds at part throttle ( which is feeding mild ports only ) personally .. goopy oversize 12a or 13b 3mm seals - all the way - ,, buy the file kit,, spend a couple of nights in front of the TV getting your apex seal slots true and slightly tighter than factory delivered |
that's mind blowing! are there any advantages other than the new secondaries having a new short runner? wouldn't the new longer primaries offer more low range tq and the new shorter secondaries shift the power band a little higher? but doesn't a non staged intake act more tame on a bridgeport? yes now im asking a lot of questions. im planning to run itb's on my build so no staged intake.
3mm seals would be too heavy i think for what im using it for (high revving), everything i've read says to use 2mm seals. thanks for your input and reassurance on the atkins seals Peejay, im sold on them now :) |
I won't use Goopy seals just because they seem to be made for drag engines, IE longevity or housing friendliness is not a concern. I'd rather have longevity and housing friendliness, given that I want the engine to last 60k miles at a minimum and have good housings left over when it's done, and I'm not concerned about how well the seals handle detonation at 30psi boost.
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Originally Posted by peejay
(Post 11150569)
I won't use Goopy seals just because they seem to be made for drag engines, IE longevity or housing friendliness is not a concern. I'd rather have longevity and housing friendliness, given that I want the engine to last 60k miles at a minimum and have good housings left over when it's done, and I'm not concerned about how well the seals handle detonation at 30psi boost.
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/\ this ...
i have a set running in an NA full bridge 12a ( street use rx2 ) somewheres, , no issues ( beyond taking a while to hand file... but these where rare MDR 12a rotors and had previously done lots of kms and race time ) |
Originally Posted by peejay
(Post 11150569)
I won't use Goopy seals just because they seem to be made for drag engines, IE longevity or housing friendliness is not a concern. I'd rather have longevity and housing friendliness, given that I want the engine to last 60k miles at a minimum and have good housings left over when it's done, and I'm not concerned about how well the seals handle detonation at 30psi boost.
Granted, I haven't taken apart the engine yet but my comp is still in the 90s but then again I have needed to take it apart yet! |
That's true... and you rev your engine a LOT harder than I ever did one of mine, judging from where you were lifting vs. where I was lifting the day I had to borrow your car, and the numbers I was seeing on the tach...
How many miles have you done on it though? :) At any rate, apex seals are not what I have problems with. Side housings and coolant seals are my problems. Side housings I fixed by going apeshit over proper air filtration, coolant seals I fixed by not using 18-gauge wire anymore. (I'm on the Viton train. I bought many yards of cord from McMaster-Carr) Interesting about the "oversize" seals. I was just about to cut up some rotors with the slots worn to .004 clearance, maybe I'll put new bearings in them (stole them for my new engine's rotors - the bearings they had were SMOKED) and run them in the next peripheral port. |
Originally Posted by peejay
(Post 11151629)
That's true... and you rev your engine a LOT harder than I ever did one of mine, judging from where you were lifting vs. where I was lifting the day I had to borrow your car, and the numbers I was seeing on the tach...
How many miles have you done on it though? :) At any rate, apex seals are not what I have problems with. Side housings and coolant seals are my problems. Side housings I fixed by going apeshit over proper air filtration, coolant seals I fixed by not using 18-gauge wire anymore. (I'm on the Viton train. I bought many yards of cord from McMaster-Carr) Interesting about the "oversize" seals. I was just about to cut up some rotors with the slots worn to .004 clearance, maybe I'll put new bearings in them (stole them for my new engine's rotors - the bearings they had were SMOKED) and run them in the next peripheral port. mileage wise I'd have to estimate around 30,000 miles |
Originally Posted by fidelity101
(Post 11141268)
if you go full bridge, I'm gonna have to go PP.
The engine seems STRONG. Even with timing at zero degrees, it cranks with authority and revs instantly when I tap the throttle. Can't wait to finish up the little bits and start tuning it. The previous engine was so worn out that when I got home on the 26th, I could floor it under 3000rpm in second gear and it would just make intake noise, not acceleration. No dust in the intake manifold or "lapping paste" in the oil pan, and no heavy oil smoke like the side housings are grooved (this EATS the oil rings) so I'm thinking that the rotor housings are missing most of their chrome. Be nice if I could just throw different rotor housings on the engine, get carbon seals, and use it as a backup engine. |
If I were trying to bridge primaries and wanted a larger runner on a GSL SE center iron...
I would sandblast the cavity above the ports through the water jacket and fill the area with JB weld. Then proceed to port with the JB as a backing. FOr extra safety fill the top layer with orange RTV sealing the surface of the epoxy to help protect agains moisture. Full Bridge all the way. |
I'd LIKE to build another Turbo II engine, I'd just need to find new end housings, which seem to be rare as hen's teeth nowadays.
But one of my Crazy Plans is to use an SA trans, front cover mount, and FC N/A driveshaft, which SHOULD all line up to give me about 6" of engine setback without having to hack the floor for shifter clearance. Doing all that would eliminate the need for center mounts. The neat thing is, I should be able to make blockoffs for the metering blocks on the Holley carb, add injector bungs, and have four injectors shooting directly into the boosters. This is what it appears the MSD throttle body does, and I have all the bits to do it, too. And, doing this would eliminate the need for injector bungs in the center housing, so the two combined would allow me to use 12A tallport center housings. First things first, get engine running on GSL-SE injectors. |
you don't NEED turbo irons to build a turbo motor, i have built a handful of complete high and low compression 6 port engines and they work about as well as the 4 port blocks except they act more like a large streetport even with stock ports.
pretty soon people won't have a choice, with everyone breaking the FC rear irons left and right and demolishing the low compression rotors. only difference is high compression turbo engines are VERY limited in boost on pump gas. no more pushing 20+psi with auxiliary injection. but the spool is impressive, similar to putting a BB turbo in place of a thrust bearing turbo. i keep contemplating building a 9.4:1 6 port, pinning it and running E85 through it and then pushing 20+psi. the 8.5:1 rotors with streetport and thrust bearing T70 is just too laggy for me now, albeit very reliable. i then swing the other way and think about a shop car PP n/a with ceramic seals and scatter shield pushing 350whp.. decisions decisions. |
on a customers car 13b 6port on na 88 rotors running e85 and a chinese turbo and e85 25 psi all day
Originally Posted by RotaryEvolution
(Post 11215115)
you don't NEED turbo irons to build a turbo
motor, i have built a handful of complete high and low compression 6 port engines and they work about as well as the 4 port blocks except they act more like a large streetport even with stock ports. pretty soon people won't have a choice, with everyone breaking the FC rear irons left and right and demolishing the low compression rotors. only difference is high compression turbo engines are VERY limited in boost on pump gas. no more pushing 20+psi with auxiliary injection. but the spool is impressive, similar to putting a BB turbo in place of a thrust bearing turbo. i keep contemplating building a 9.4:1 6 port, pinning it and running E85 through it and then pushing 20+psi. the 8.5:1 rotors with streetport and thrust bearing T70 is just too laggy for me now, albeit very reliable. i then swing the other way and think about a shop car PP n/a with ceramic seals and scatter shield pushing 350whp.. decisions decisions. |
Originally Posted by RotaryEvolution
(Post 11215115)
you don't NEED turbo irons to build a turbo motor, i have built a handful of complete high and low compression 6 port engines and they work about as well as the 4 port blocks except they act more like a large streetport even with stock ports.
I have a whole lot of 6-port end housings, they mainly are just sitting and rusting because they're useless for me. When I rebuild the GSL-SE engine that just came out, it's going back together with 12A end housings. |
Originally Posted by flaco
(Post 11215153)
on a customers car 13b 6port on na 88 rotors running e85 and a chinese turbo and e85 25 psi all day
you said turbo engine PJ so i assumed you meant with a turbo. :) |
The way 13B-RE and -REW engines are coming down in price, I might see about using one of those someday :)
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what are you smoking? :rlaugh:
i can't even find cores and i don't trust the importers for as far as i can throw them. even FCs have dried up in the pick a part yards so no more n/a blocks there. i'm doing double time refurbishing parts! all the broken irons are going to have to be coming off the shelves soon and are going to have to get welded and cut. i should have hoarded more years ago when they were like flies filling up the yards and bought more FD questionable blocks for $450. FC irons are just weak, they're breaking in droves these days in various ways. |
That's why every engine I've run in the past couple years, save one, was half-bridge.
Ayn Rand |
And the verdict is in: BRIDGE THE PRIMARIES.
Oh my, yes. Drivability even with a very rough tune is great. A little bit of stumble when pulling from a stop, but this may also be due to the 9lb flywheel. It doesn't buck like the peripheral port did. As a first cut I added 20% more fuel everywhere, and it was still running at 16:1 at 3000rpm. :eek: Daddy likes, oh yes he does... And the intake is louder than the exhaust. It's weird. |
the intake is louder than the exhaust.....on the old intake or the other design? curious. i know what you mean though, people over exaggerate the buckyness of a Bridgey. congrats and looking forward to hearing how she runs after a good tune. hmm hopefully we can get an exhaust audio clip? me loves the sound of brap brap. :)
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So how did this turn out for you peejay?
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Still running strong 10,000 miles later.
Haven't been back to the dragstrip because they closed for winter shortly after I put the car together (day I tuned it there was the last weekend they were open) and they only just started running again a couple weekends ago. My gut feeling is that compression might be a little down, since it doesn't seem to have the midrange "pop" that it used to have, but I never checked it when it was fresh, so it's a little late now. Still only on the two 680s too. |
Lookig good! There is rallyX at south lyon on the 25th and then later that night the engine is coming out. I'll be sure to post photos of the housing wear with the RA seals.
My comp is down, oil consumption increased, fuel dillution increased, power is down and the other day when I did a 2nd gear pull I looked behind in the mirror and saw a large cloud/mist of blue and black where I initially gunned it lol. I'm borrowing a go-pro for May's event and I will be sure to have it reward for some gnarley roosters and hopefully a big cloud of blue. |
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