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TPIS Mini Ram WARNING!!

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Old 01-27-2007, 09:00 AM
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Default TPIS Mini Ram WARNING!!

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.
 
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Old 02-03-2007, 04:19 PM
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Default RE: TPIS Mini Ram WARNING!!

TPIS Mini Ram, Additional Information [/align][hr]

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...surem ent.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
 
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