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Just a couple of teasers mocked up on the motor. I need to make a new fuel crossover line as the dorman requires a few more inches.
Another thing was that my brand brand new GM 2bar MAP sensor broke getting it out of the old intake. I was frigin livid. Only 9months old and $50 down the drain. When I get the new one I'm going to explore new seals that aren't impossible to get out.
Mocked up with fuel rails fillet mounted. Though I might have needed a 45* AN fitting but figured a way out as that's the only fitting I didn't have lol.
Everything bolted Up to the intake. I swapped out the injector orings as the dorman comes with 2 sets of different thickness. I swapped the thickest ones on. When I put mine originally in the slipped right into the intake with little fuss and I can see that being a boost leak. So the thicker orings made it nice and tight. Fuel line in the front was interesting to figure out. The dorman intake is overall just a bigger intake and fatter/rounder. I am going to have to figure out wiring harness routing and prob have to lengthen some wires.
Thinking of picking up aftermarket accessory brackets. Since I'm going more for looks I'm thinking something billet to match the supercharger on the other side to even out the engine bay.
I got mine running on my NA '66 c-10. I am really interested in your results putting some pressure in it. I'll be honest and say that I am skeptical enough of mine to leave it on my NA motor and keep the stock intake for the boosted motor
we will see! I'm a novice style tuner, so it isnt exactly easy. My original tune was pig rich at idle like 10:1 bc my custom cam is only pulling like 13-15" of vacuum. So I leaned out the VE table and have gotten it to 14-15:1 at idle. Seems to be idling in the 55-65kpa range. But I am seeing weird timing issues and it was hunting before I got it leaned out. But I can't get it to idle lower than 700-750rpms. Ive tried 2 TBs and had the idle screws backed all the way down.
Starting to think the cam just wants to idle that high. But its not a crazy cam... cam motion 214/228 .561/.561 115.5+4.5 and I was told it would idle like stock. I think it was picking up knock as timing was only 8* when I was commanding 19-21* it was always between 8-14*. I eventually got it to idle at 18.5 but I had to increase the min timing to 18.5 in the idle ranges for knock.
we will see! I'm a novice style tuner, so it isnt exactly easy. My original tune was pig rich at idle like 10:1 bc my custom cam is only pulling like 13-15" of vacuum. So I leaned out the VE table and have gotten it to 14-15:1 at idle. Seems to be idling in the 55-65kpa range. But I am seeing weird timing issues and it was hunting before I got it leaned out. But I can't get it to idle lower than 700-750rpms. Ive tried 2 TBs and had the idle screws backed all the way down.
Starting to think the cam just wants to idle that high. But its not a crazy cam... cam motion 214/228 .561/.561 115.5+4.5 and I was told it would idle like stock. I think it was picking up knock as timing was only 8* when I was commanding 19-21* it was always between 8-14*. I eventually got it to idle at 18.5 but I had to increase the min timing to 18.5 in the idle ranges for knock.
Made some changes and fixed some stuff thinking they could be leaks. I tried starting it up and have the same issues. Surging idle, low vacuum but not getting anywhere with the tune.
I agree with andrew, how are you checking for leaks? I like the can of ether (starting spray) or carb cleaner method.
I've been working on rigging up a smoke tester, that'd be the ticket.
with my intake I took it apart and epoxied it together while bolting to the motor to seal the upper to the lower permanently. I was getting leaks in the back and the front before that.
You sealed the intake on the front and back? It leaked when it arrived? Your talking about the dorman intake right?
Intake vacuum ports are full blocked off, vacuum caps on all intake nipples. Rear brake booster port goes to vacuum block. I tested the assembled vacuum block and it holds vacuum. I then tested both BOV's and only one has a slow leak down. Ive tried getting it to hold vacuum steady but Ive only slowed it down.
I sprayed starting fluid on the TB flange area, MAP sensor, PCV, catch can, intake ports. I didn't spray the back and front of the intake where they meet. I didn't see or hear any changes in idle rpm.
I have gotten the tune to be alittle better on my last try. I added a good bit of air to the base idle airflow table. The idle is stabilized and fluctuates around 750rpms now. I have increased timing to 24ish* and have AFR in the 15:1 range at idle and warm around 180*F. However my idle vacuum is till crap at 14-15" and it was higher when I had it it running 12.9-13:1 at idle and dropped to 14.2:1 at idle. Still trying to figure where the missing 4" is going to. I have given it throttle and as rpms increase vacuum increases accordingly.
yeah it leaked especially in the back, but only after I torqued it down to the motor...it warped it a bit i think. there are three torx screws back there and two up front and i think thats where my leaks were.
i have a really tame cam so it idles around 19" mercury and 575 rpm.
have you done any IAC relearns when adjusting the throttle blade idle screw?
that cam should idle way better than your describing it.
also i would try raising the rpms up to like 800 and then see what afr it likes. my turbo truck cam likes ( liked ) to idle at 15.5-16 , lock the timing at 20 and see what fuel it smooths out at. dont missile lock on getting it to idle at stoich or a certain inches of mercury.
good luck and check those spots i mentioned. i'm still tuning mine but i think there's some upper mid range power to be had from this intake.
so it's not much taller overall per se, but instead of the bolt bosses taking up the headroom on the stocker, this intake has the bosses incorporated in. they are not brass inserts like the stocker, but plastic holes that take a very sharp and coarse thread like a wood screw.
the stock intake cover fits right on it, as well as the fuel rails, etc...
yeah it leaked especially in the back, but only after I torqued it down to the motor...it warped it a bit i think. there are three torx screws back there and two up front and i think thats where my leaks were.
i have a really tame cam so it idles around 19" mercury and 575 rpm.
have you done any IAC relearns when adjusting the throttle blade idle screw?
that cam should idle way better than your describing it.
also i would try raising the rpms up to like 800 and then see what afr it likes. my turbo truck cam likes ( liked ) to idle at 15.5-16 , lock the timing at 20 and see what fuel it smooths out at. dont missile lock on getting it to idle at stoich or a certain inches of mercury.
good luck and check those spots i mentioned. i'm still tuning mine but i think there's some upper mid range power to be had from this intake.
i was doing TPS relearns after each TB blade adjustment. I didn't know there was a IAC relearn. I have got the IAC counts in the 50-60 count range and TPS is in the .52-.57v range.
AFR is In the 15:1 range and vacuum dropped after leaning it out from 12.9-13:1.
Im going to pull the intake and see about the front and back sealing. What kind of epoxi did you use.
but any 2 part polyurethane will work great on nylon
yeah this def moves more air than the stock truck intake 2500 rpms and up. had to add a bunch of fuel on the VE table. wish I could dyno it back to back
Well I decided to rule out the intake competely. I pulled it off and swapped on a new OE replacement GM delphi intake I had purchased with new intake gaskets. I swapped everything over and I have even less vacuum than before. I'm now only pulling 13.2-14" of vacuum at idle but idle is steady and I'm still in the 60-70 IAC range without getting to full warm temp. I Vacuum checked everything connected to the intake again and have no leaks. I lowered the idle rpm and it was dipping into the high 600's as it was warming up. Timing is around 24* base. I didn't do a tps relearn this last time as i lowered the TB blade slightly due to me commanding lower idle RPM, still was in the .47v range and 0-.4% at idle. So now I'm questioning other things.
1.) I thought the pushrods might be too long. The heads were supposidly milled .005" to clean them up (no idea as it was off ebay reman heads and I didn't check pushrod length) and I went from graphite head gaskets to MLS and also running the 5315 morel lifters. I was told the stock 7.4" pushrods would be fine. I pulled a valve cover and checked the rockers and they seemed tight still on the driver side.
2.) Thought the cam could be off a tooth, I looked back at some pics I took and it looks dead on (dot to dot).
3.) I'm thinking This might just be the cams vacuum given that my supercharger is pushing a good bit of air at idle. A stock 5.3 should pull 22.5" of vacuum at idle, I was only pulling 19-19.5" before the cam swap. That means Ive lost 3-3.5" of vacuum with the stock cam. If I'm pulling 14" with this cam that would put me at 17-17.5" of vacuum at idle if I'm reading 3-3.5" lower (i can only assume its from the supercharger).
dot to dot could mean anything these days bro. you GOTTA degree that thing.
dot to dot on the 5.3 in my daily (that uses this intake) was 6* retarded!
finally got my intake running a bit better...it had compressed a bit around the bolt holes (there are no washers or load spreaders like the stocker) so I'm sure it was leaking a bit.
but the VE tuning so far is going well. Just needs some spark tuning and then I'll put it back on the MAF
pardon me for not going back through your thread to find it, but what is your cam specs?
there are some pretty good calculators out there to estimate vacuum from given cam specs.
but again, dont fixate on a the highest possible vacuum signal. just get one that is stable for your motor.
01-23-2017, 07:22 AM
) to idle at 15.5-16 , lock the timing at 20 and see what fuel it smooths out at. dont missile lock on getting it to idle at stoich or a certain inches of mercury. 