Last summer I dug out my TPIS MiniRam and installed it on my newest 408ci SBC. Last December I tried to install a set of 1.6 ratio Crane rocker arms but the push rods were touching the head. I removed the Miniram and to my surprise I found that the port impressions in the manifold gaskets from the Miniram were 0.100 inch lower than the cylinder head ports. I wondered how this could be, as the ports in the GM heads are huge (Felpro 1206), 2.150" tall, and intake manifolds are always smaller to avoid a ledge that would cause significant turbulence and hinder air flow. The MiniRam Ports are Felpro 1204, which are 1.99" tall. I checked the thickness of the gasket seal surface below the port on 6 sets of standard port 23 degree SBC heads, and all had from 0.250 on stock mid 1980 GM heads down to 0.175 on all out Bowtie heads. The average of these heads was about 0.230".

Thirty years experience in the Automotive world as a mechanic, Journeyman Toolmaker and Mechanical/Electrical Engineer in areas such as cast product and manufacturing engineer, powertrain design engineering and powertrain research tells me that 0.230" is a good seal surface and that I needed to take a close look at the MiniRam. What I found was that the port floors on the Miniram from bank to bank appeared to be too low and/or too close together. If the ports are located properly on the face of the Miniram, as Tuned Port Induction Specalties insists, then the only other possibility is that the port faces are machined too close together, allowing the manifold to drop too far into the valley.

I managed to get two measurements from TPIS from one of their manifolds. The measurement they offered was of the vertical location of the port floor, the other measurement (one I requested) was the distance between the port floors from bank to bank (manifold upsid down). The measurement they supplied was useless and made no sense unless their memory or math was seriously off. I compared the measurement I requested to my manifold (which was much narrower) and calculated the thickness of intake gaskets I would need to raise the manifold high enough to get the port floors of the Miniram and head to line up. The result was that I needed between 0.175 and 0.198" thick manifold gaskets to align the port floors on three of my long blocks, all of which have much larger ports than the Miniram. Even the Miniram TPIS measured needed 0.126" gaskets to work on any of my engines. I compared the TPIS bank to bank port face floor spacing to several other manifolds, and my Miniram was much narrower, another strong indicator that it was not machined correctly. TPIS tried to accuse me of modifying the ports, but they are the exact dimension of the smallest port openings TPIS made and I know the complete history of my manifold.

I made many other measurements not discussed above to make sure I didn't have a bunch of oddball blocks, heads and manifolds. I also used some old GM performance manuals with block, head and manifold drawings.

Sometimes you just have to suck it up and move on, but this Miniram manifold was expensive! I've run into other bad companies, like Scat- rods with forging cold shuts and poorly aligned big and small ends, machine shops that bench grind splayed main cap registers before line boring, bending connecting rods to align big and small ends because of poorly installed bushings, aligned boring mains 0.002" too large, crankshaft main journals ground with different centerlines, Eagle crank journals ground to small, cam dowels mis-located, partially machined piston rings, piston sets with 20g variations......

In summary STAY AWAY from TPIS Mini Ram manifolds.

 

They have them on E-bay sometimes. Maybe returns. Thats a nice article. Thanks. I was considering getting them next year. Not probably going to now.

 

Are you sure you didn't overlook something? Or could that manifold just be a bad manifold?

Over the years I've seen progress pictures of several peoples builds, and one firsthand where the MiniRam II (not the original) was port matched to the cylinder heads. None showed the port misalignment you refer to.

 

Interesting. I found out the same thing with my Edelbrock TPI intake manifold. With my latest buildup I had the heads milled and the block decked. Also using a .028" head gasket. I figured I was going to have to mill the intake manif0old to make it match up right.

Well low and behold I had been running the intake with the old combination sitting to low as you had with the Miniram. It was also about .100" low. With my new combination it actually turned out right. In this case an error in my favor. By the way I bought the Edelbrock manifold when they first came out in 1990/91. So maybe they have corrected them since then.

 

I have had no perceptable alignment problems with my first-gen Miniram. It sits on a 1969 block with AFR195 cylinder heads and a 9.005" deck height.

 

Miniram seems to be hit or miss. You see about as many threads with satisfied users as you will with people who run into serious issues.

 

you sure you just arn't checking it against raised port heads(sounds like it)?

 

All the more reason to go with a modified and ported LT1 intake, not to mention the huge load of cash you will save. TPIS has been worthless and irrelevant for years. I don't see that changing anytime soon. Sorry you got burned bro.

 

glad i got rid of mine... i had to do alot of work with mine as well unfortunately and it still wasn't worth anywhere close to the money it cost.

 

After I had problems with a milled accel base years ago not fitting properly, I've learned to trial fit/measure any intake that goes on the car before any rtv or bolts go in it.

You can use the fel-pro 1266 gasket, it is .120 and the 1206 is .060.

 

it's unfortunate but you almost have to do that with any aftermarket piece these days.

 

I just got a miniram last year and it bolted right up and seated perfect. No problems whatsoever. Been about 7K miles on the new topend.

 

I was at my Uncle's shop yesterday and measured a GM TPI and a Q-Jet manifold in addition to the 4 manifolds I have.

Below are some pictures of how the measurements were taken and a file containing the measurements and calculations showing how far off my Mini Ram is. If TPIS didn't put such long slots in the bolt holes it never would have bolted up.

All the heads and manifolds are stock port location and stock 23 degree angle. Felpro 1204, 1205 and 1206 gaskets are standard port locations.

Before the plastic (nylon) manifolds my employer (and department) made more than 3 million aluminum intake manifolds a year. All intake manifold port face openings are smaller than the cylinder head port opening to avoid a ledge in the direction of flow that will reduce cross-section area and result in turbulance that will further reduce the effective flow area. A mismatch in opposite the direction of air flow has little effect.

http://webpages.charter.net/454corva...easurement.JPG

http://webpages.charter.net/454corva...easurement.JPG

http://webpages.charter.net/454corva...Ram%20Data.mdi

http://webpages.charter.net/454corva...20GM%20194.JPG

http://webpages.charter.net/454corva...1%20ported.JPG

http://webpages.charter.net/454corvair/454%20Corvair/


I am milling up two 0.125" aluminum spacers and will be using two 0.062" gaskets to get the TPIS port floor up where TPIS should have made them.

The TPIS manifold is so narrow and sits so low it's port floors (if min 0.030" gaskets were used) it would be 0.095" above the cylinder head deck face. If I were to try to port match heads to the manifold the port floor and sealing face would be nearly gone. Proper port location is why I never buy used intakes that have been ported. This manifold is a case where even that level of caution would not be enough, even for a "new" manifold.

My TPIS was first run for a short time on my 355ci Gen2 Camaro and luckily ran with no leaks, I didn't port check it because the cylinder head port openings were significantly larger than the TPIS and the TPIS ports were "as made". My brother removed the manifold the first time so I didn't see the mismatch.

TPIS sounded like they would take care of their defective manifold and told me to ship it back. I been down the road with Scat (and never got my rods back!!!) so I pushed them for a commitment on what they would do. Three week later, after measuring 6 sets of heads (and now 6 manifolds) etc I had proof this manifold was machined wrong by TPIS. If the discussion would have gone beyond "...sorry your 1 year warranty is up..." I was more than willing to pay for them to CNC the spacers if we could agree on a way not to have to ship the manifold back for inspection. Stuck in the @$$ Again!!


This is the kind of problems "Engine Builders" find that "Engine Assembers" don't run into. I was acting like a assembler with that manifold (it was NEW and CNC'd D@^^ it!!!.)

Another problem I run into is double roller timing sets rubbing the block at the bottom of the center main oil galley boss. I had to do a lot of grinding to get proper clearance on the last three 400 SBC's. Years ago I used to wondering why so many cars with fresh engines were for sale.....

Back to the shop....................

 

mine seated fine as well... did it run the way it should have though? no. i didn't notice anything odd but i went to have everything gone over to insure i got what i paid for and i didn't. had i never done that i'd still have the 383 miniram in my car today and have no idea... i spent alot of money fixing their mistakes and making that intake worth anything.

TPIS is a joke, but that's just my opinion. from their machine work to their programming they have been nothing but second rate and i've tried them several times on various things just to make sure. guess i just got alot of bad parts from them over a period of a few years.

crazy..

 

Your correct they suck and so does the service.