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I want to buy a GMPP TBI to Vortec intake.
Like this:
http://paceperformance.com/i-6255261...-with-egr.html
I already missed out on a couple of decent deals on ebay and I am looking to find a good deal on a used one rather than pay the high price for a new one.
So if you have one you want to sell or know anyone that has one they want to sell, please PM me.
Thank You
This intake only offers mild performance gains over stock. A factory 86-87 aluminum 4bbl quadrajet manifold with adapter can provide greater gains while retaining EGR and factory manifold heating and it bolts right onto the factory heads.
http://www.ebay.com/itm/Chevrolet-OE...cfe58e&vxp=mtr
(Not my part)
I agree, the factory cast Q-Jet aluminum intake is often over looked as an affordable intake option for SBC cast iron heads 1986 and before. Unfortunately, the TBI heads from 1987 ~ 1995 had the center bolt holes angled differently, so the factory cast Q-Jet aluminum intake is not a simple swap to TBI heads without elongating the center mounting holes.Quote:
Originally Posted by 1project2many
I think Devin is looking for an intake that will bolt to the 1996 / newer Vortec heads that have eight intake mounting bolts.
dave w
That is correct Dave,
I need a intake for the 1996 and up Vortec heads.
What I like about the GMPP intake is it allows the water to flow from all 4 corners of the heads allowing the the water from the back of the heads to flow through the intake towards the thermostat. There are some issues with running Vortec heads with the way the water flows through them. GM eliminated the block bypass when the came out with the Vortec heads and that is why the water pumps have 2 bypass ports one for a constant bypass and one for the heater.
I assume the fact that this intake has the the water passages and egr gas passage cast into it the way that it does is what makes it so expensive. I would imagine the process to cast it is a lot more involved.
Look at the pic I added you can see all the passages on the underside.
Devin,Quote:
Originally Posted by devind
Just wondering if you have given any thought to converting to the 1996 ~ 2000 Vortec MPFI system using the '427 PCM? It could be done in two steps, first upgrade to the '427 PCM, then install the 1996 ~ 2000 Vortec MPFI system. I have experience doing both conversions, and would be willing to share my notes.
dave w
Have I thought about it? YesQuote:
Originally Posted by dave w
Am I intimidated about it? Yes
Worried about expense? Yes
Worried about time it would take to start over? Yes
Concerned about starting over when this close on current setup? Yes
Concerned about complicating the efi setup? Yes
With all that said I am still interested in what you have to show me.
I would really like some kind of TPI or ram setup like used on the Ram Jet engine. But that is definitely is out of the budget I would imagine.
The set up now makes more than enough power for the Jeep but anything I could do to improve overall drivability would be good. But I would like to keep it simple; I am a big fan of simplicity.
I figured in you area, used 5.7 Vortec intake systems / parts would be affordable? Seems the Vortec heads were the "In Demand Items" not the intake systems.Quote:
Originally Posted by devind
Would it be as simple as a TBI? No
Would it be as complicated as an 0411 PCM? No
Would the fuel pressures increase? Yes
Can you reuse the TBI distributor? Yes
Would the current belt drive system need modification? Maybe ~ Depends on what is bolted to the current intake manifold.
Is there any additional wirng? Yes ~ Injector Pod and sensor connectors ends.
I'll post additional information soon.
dave w
Dave,Quote:
Originally Posted by dave w
I have been thinking about this and as much as I appreciate your willingness to help me and share your notes with me. The more I think about it, I am not sure this is the vehicle I want to learn to do a MPFI on. I kind of like the the simplicity of the TBI system being on this vehicle.
I know there will be a MPFI project in my future and I hope your offer will still stand. However I still might be interested in upgrading to the other ecm. You mentioned this to me before.
I lost track of the Vortec needs. The TBI Vortec is still not the best choice. It is a copy of a factory manifold. If you are not forced to use EGR there are plenty of good carby intakes available that would work with adapters.
Coolant under the manifold is to aid emissions. It is not there for cooling. The bypass in the old block exists to circulate coolant from below the thermostat ensuring warm coolant reaches the 'stat and causes it to open. You can do the same thing by adding a small hole to the 'stat (about 1/8"). If you aren't in an area where it gets really cold this won't cause problems. If it gets below 20 deg the engine might not warm enough. Additionally, you can install small nipples and use 3/8" hose to create a small bypass path to the water pump. What you do not want to do imo is use 1/2" heater hose to create a bypass path. The stock intake has a dual valve 'stat that closes the bypass as it opens the radiator. A traditional 'stat cannot close the bypass path and a 1/2" hose may allow large amounts of coolant to bypass the radiator.
I have already been running a Weiand Intake with a custom adapter I machined for a while now.Quote:
Originally Posted by 1project2many
The first problem I had when I got this setup going a year ago was when I went to break the cam in the engine warmed up and started to overheat right away. After some diagnosing the problem, I came to the realization the water pressure from the water pump was forcing the T-stat closed. At the time I cut the center out of the T-stat and was able to break the cam in.
Later on I got a high flow T-stat with 3 – 3/16” holes drilled in it and it worked fine except when it is cold out it allows too much water to bypass and it won’t warm up above 150*. So to cure this problem I got a high flow T-stat without the bypass holes and it works good but now the heater core make funny sound when the T-stat opens and closes from the water the bypasses through it.
So what I am wanting is an intake that will ether flow coolant like the GMPP or has provisions to plumb the water from the back to the front. I was going to drill and tap the intake I have but there really isn’t much material there to do it. However I have found some cheap carb Vortec intakes on ebay that I can plumb this way. http://cgi.ebay.com/ws/eBayISAPI.dll...m=171073251560
I am planning on running a standard bypass hose straight from the intake to the water pump. Then I will either add a nipple to the radiator next to the lower outlet or make a tee to go inline in the lower radiator hose so that I can plumb the heater from the intake to heater core, from core to lower radiator hose. I am running a high flow reverse rotation Edelbrock water pump, I wish there was a way to just add another bypass port to it like the big block water pumps have.
I have done some internet searching about this issue and really wasn’t finding a whole lot of people having this problem than just the other day found some guys on the Tri 5 forum that was having the same issue with their Ram Jet crate motors and this is what many of them did to cure the problem.
The pictured adapter looks very similar to the design I came up with . See pics below. I've made a few improvements since I made these screen shots.Quote:
Originally Posted by devind
dave w
Yea, the picture is of the one I made earlier this year.Quote:
Originally Posted by dave w
It's amazing that the Edelbrock pump can make enough pressure at the thermostat to keep it closed. I've tried to muscle t-stat's closed before and they generally have a fair amount of pressure. Plus the pump isn't anything more than a splash type pump, like a TBI pump with much greater clearances. But I guess .08 in sq of opening added to the 'stat made a large enough difference. How did you determine pressure was forcing it closed?
All you need to get the 'stat to open is enough warm coolant to provide a signal. Ever look at the front of an Olds 350 / 455 intake? I'm really surprised none of the manufacturers have built the bypass in using that method and a different coolant outlet and supplying a block off plate if the bypass isn't not needed. Wishful thinking, I guess.
People get excited about drilling holes and tapping the manifold for a bypass but why not use a thermostat spacer? http://www.behrents.com/c/Cooling-HousingThermo.html
http://www.behrents.com/mm5/graphics...l/BRP587-L.jpg
No, the pump doesn't lend itself to easy drill and tap procedures.
Do you have a restrictor on the heater hose from the inlet pipe?
Quote:
Originally Posted by 1project2many
I don’t know exactly what the deal is but is has something to do with the water flows through the Vortec heads. Since the 1996 and newer Vortec blocks did not have the bypass on the passenger side of the block at the water pump mount, apparently the heads have a little different design as well. Also when you are trying to muscle the T-state you were probably trying to open it. When in the intake the water is actually pushing against the back side trying to close it.
I ran the same pump with the TBI heads for several years and never had a problem.
It wasn’t until I rebuilt the motor and went with the Vortec heads that I started having this problem.
I thought I might have something else going on. It wasn’t until I found the thread on the Tri-5 forum were guys were having the problem with their Ram Jet engines which also run Vortec heads that I knew for sure I was diagnosing the problem correctly. Some of those guys were running standard stock pumps and still having the same issue. Most guys just say they run the T-state with the bypass holes in them and never have a problem. But with EFI I want the water temp to be consistent.
I’m not sure about the heater hose fittings. They are the same ones that I ran with the TBI heads. I was actually thinking about that the other day when I noticed it making the funny noises. I was trying to remember were the smaller one goes. If I’m correct the smaller restrictor fitting actually goes on at the water pump to create some back pressure and help keep pressure build up in the heater core. Does that sound correct?
The link to the 1227747 ECM to 16197427 PCM http://www.gearhead-efi.com/Fuel-Inj...out-Directions!
The simple easy way is to use a Plug-n-Play adapter. See pic below. R.I.P to the 1227747 that donated it's connector.
dave w
Thanks Dave,Quote:
Originally Posted by dave w
Apparently in your opinion this is a worth while up grade!
I have seen on here how many more tables you have the ability to tune with this PCM. It makes since that it would be a better engine control not sure I even have a good handle on the 7747 yet. But there again I never thought I would even close to where I am now with the 7747 so maybe I can learn the 7427 too.
What was the 7427 PCM originally used in?
The deal is this: In the old coolant path water could circulate from the forward portion of the RH head, through a passage in the head gasket, into the block, and out through a 5/16" hole into the coolant pump. Inside the pump this coolant was routed to the inlet side, and the pump would circulate the coolant back through the block. This helped ensure some warm coolant reached the thermostat so the 'stat would open.Quote:
I don’t know exactly what the deal is but is has something to do with the water flows through the Vortec heads.
As the need for cleaner emissions increased, faster warmup times and better vaporization of fuel became more important along with reducing variation int intake air temperature. Later carburetor and TBI intakes routed coolant from the front of the intake, under the throttle body or carb, and back to the heater hose fitting. Coolant would circulate through the core and return to the pump or on some HD trucks, to the radiator. This routing also provided a faster and more accurate heat signal to the thermostat so it would open properly. Coolant always flowed through the heater circuit and if a restrictor wasn't in place, it could cause overheating as radiator performance began to decrease. In my experience the restrictor is always found at the manifold side (outlet). Although the bypass circuit is still present in the heads, some of the TBI truck blocks do not have the 5/16" hole in the RH side of the block for the bypass circuit. Its been a "gotcha" that guys have had to watch for since the late '80s.
With the '96 and newer 5.7, GM decided to approach faster warmup and consistent temps in a completely new way. They did away with the bypass circuit in the heads and the block and replaced it with a much larger bypass circuit connected externally from the manifold under the thermostat to the water pump. This alone is nothing new. In fact, the Chevy smallblock was one of the few engines that didn't have a large, external bypass circuit prior to '96. But what was new was that the bypass circuit flow was now linked to coolant flow through the radiator. As the thermostat opens to allow coolant out of the manifold to the radiator, it also closes the passage that leads to the bypass circuit. In this way, temperature in the block is encouraged to stay at the same temp as the thermostat opening temp.
When installing Vortec heads on an older engine, you don't have the advantage of either bypass circuit. The old internal ports aren't present in the head and the external passage doesn't exist. Consequently there is no "flow path" for warm coolant to get to the thermostat and cause the wax pellet inside to expand and open the 'stat. Drilling a small hole in the stat allows coolant to flow directly past the 'stat so warm coolant will arrive eventually. The trick to this is in two parts. First is drilling a large enough hole so the back of the block and the heads don't overheat before the thermostat gets the signal that it's time to open. Second, on a street vehicle used in cold weather, the trick is to drill the hole small enough so the engine can actually warm up and provide heat.
A second method to ensure some warm coolant gets to the 'stat is to connect the heater to a port as close to the 'stat as possible. Ensure there's no heater shutoff valve on the heater circuit and the 'stat will usually get a strong enough signal to open in reasonable time. If heater flow is blocked, however, there's a good chance the engine will overheat because the 'stat will no longer be exposed to coolant that's at the same temp as what's in the head and block.
The third method is to plumb an external bypass into the manifold. But the problem here is twofold. If the external bypass circulates between manifold and pump it tends to reduce cooling ability in summer. If the external bypass circulates between manifold and radiator it tends to reduce engine heating in the winter. In either case the bypass should be sized to only allow the minimum amount of coolant necessary to make the thermostat open. 1/2" and 5/8" openings are not appropriate for this bypass.
I have tried forcing a warm thermostat closed before. I do strange things like that sometimes. It takes a fair amount of force.
I have run Vortec heads on an older engine, and I have a non-stock intake that I intend to install on a Vortec engine in the future. I am very seriously considering making a spacer like in the picture which will allow me to use the stock Vortec thermostat and be machined for the same type of bypass circuit flow control. Of course projects around here move slowly these days who who knows if it will happen. But it seems like the cleanest and most appropriate solution.
I don't know if noise in the heater core would be an issue for me. I have an older Toyota pickup and those are notorious for making burbling noises in the heater. But adding the criteria of "no heater noise" to the solution makes it more challenging and more fun to work out.
Quote:
Originally Posted by 1project2many
Excellent information and much appreciated!!!
Thank You for time you must have spent to put all of that together.
You're welcome. It's the result of years of learning.Quote:
Thank You for time you must have spent to put all of that together.
Bringing this one back from the dead....My L31 brand new short block is at the machine shop, I've just had it pulled it apart to double check all the clearances, had the the block decked to reduce the quench area, have had the balance checked and will be fitting the new roller cam.
The Vortec heads have been machined for screw in studs and guideplates and are ready to be bolted on.
I will be using the GMPP TBI/Vortec intake manifold and when done the engine will going in my 94 G20 van (yes it's the same motor I started working on a couple of years ago)
Anyway I've been doing a lot of reading about the external coolant bypass required for the Vortec heads with non factory intake manifolds and the description above is the best I've seen after many hours of searching.The way the factory Vortec thermostat closes the bypass as it opens makes a lot of sense but unfortunately aftermarket manifolds aren't designed to work like that.
I've checked my new L31 block and the coolant bypass hole from the front of the block does enter make a turn and come out on the block deck so coolant would flow through it, is there any reason why I just can't use the head gasket as a template and drill the missing coolant bypass hole in the Vortec head?
I will be using a standard counterclockwise rotation TBI water pump which unlike the Vortec water pump has the passage for the coolant bypass on the passenger side.
My factory heater hose does exit out the rear of the intake manifold and after a bit of tracing out looks like it eventually returns to the radiator, it passes through a tee that diverts coolant to the rear heater core and then up to the heater control valve which without pulling apart I assume it either sends coolant through the heater core when required or if it's closed bypasses directly back to the radiator.
From what I've read elsewhere by having the heater hose from the rear of the manifold effectively returning to the radiator you don't need the external coolant bypass plumbed at the front but the factory TBI heads still used the internal coolant bypass passage so would it hurt to do the same as the factory setup and just drill the coolant bypass hole in my head?
Sorry, I can't figure out why the spacing keeps disappearing after every sentence? It looks a mess....
Figured it out, for some reason I needed to go into general settings and change the message editor interface!
Honestly I did a different approach on the last Vortec I built for a carb application. I have had numerous OEM Vortec blocks that had the bypass hole in the block cast and machined into it. Only the matching opening in the head surface was cast over. I drilled the Vortec head for the bypass passageway. Internal bypass with no external plumbing or drilled thermostats.
Thanks Fast, I figured that drilling a hole in the head for an internal bypass should work but in the hundreds of different posts I read most people were running external bypasses or drilling holes in their thermostats. Oddly I only found one post were someone mentioned making it internal but they didn't give much detail.
With the GMPP TBI/Vortec intake manifold I won't be running an external EGR connection and I'll be blocking off the EGR port on the manifold, does anyone know where you can buy a threaded fitting to block of the EGR entry into the manifold? I was also thinking of plugging the two EGR holes in the plenum floor, to me it looks like fuel could enter the redundant EGR cavity under the manifold?
You need 6269414 fr the EGR blockoff plate
Pace Performance
http://paceperformance.com/i-6255734...z4-engine.html
http://www.chevypartsprime.com/oem/g...cover-egr.html
GM parts direct
http://www.gmpartsdirect.com/oe-gm/6269414
peace
Hog
Hi Hog,
Thanks for the reply.
I was going to make my own block off plate, I actually needed the pipe hole plug for the intake manifold.
Your part numbers helped me track down the part I needed http://www.jegs.com/i/Chevrolet-Perf...56596/10002/-1
Now I just need to find one from somewhere were the freight is less than $43...
Cheers
Andrew
It is actually a hydraulic fitting size. Might be able to track down one local. I tracked down a cap for the EGR port on my Thorley headers when I converted to the Marine intake. Been a while but I want to say it is a JIC fitting.Quote:
Originally Posted by Kitch
Just wanted to chime in and say thanks for a great thread. Bookmarked!
I am fighting through this right now. Drilled holes in my tstat this morning. I drilled 3 holes at 3/16" diameter. Still having issues. Things are fine for awhile (hovers around 195) but after running more than 35-40 minutes the engine can't cool below 215. Doesn't get above 225 though. Very strange. I have another thread going on that and once I figure that issue out I will come back and post the solution here. Starting to think my heater core is plugged or connected backwards. FWIW there is no heater control valve on my truck. Not sure if that matters.