98_1LE

I got my Accel TPI base and runners tonight. I have to say that the ports are better quality than I expected, very little clean up necessary. They match the gaskets pretty well. I can't wait to get the heads/cam/intake/headers installed.

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87 Formula 350 13.94@96.67
98 Z28 1LE 13.15@107.59
1LE Owners Association

james_fearn

I got mine but I was sort of disappointed in the runners. They have nice openings but they then neck down (via chamfer) quite a bit in the actual runner part. My roll sander fits nicely in the base but won't go in the runners w/ the sandpaper in place (for size difference reference). It may not be all that great but at that diameter that small amount is a pretty good size.

The base was beautiful. All I need to do is sand down the rough cast surface.

James

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1985 Z-28 305 TPI 223,000+ mi., Original Eng.,T-Tops,Blue/Grey
STB,SFC,GW "wonderbar",145 Speedo

Z_Ghost

Ok Mr no show up for SWMG. I got 5 runs in at the track friday night and could have done more.
Glad you got the intake, I want to see, as it sounds like it will be some time before I get my intake.

Yelofvr

James: Not sure if you know this, but the runners are intentionally designed smaller diameter than the base openings. The reason is based on manufacturing tolerances and core shift. It is impossible to cast the runner openings in the exact right place due to normal process variation(core shift). In order to avoid a situation where you have a "step up" discontinuity to the incoming air, the runners are always made smaller and have some chamfer. This is exactly how the stock manifold is designed also. If the core shift on the runners goes one way and the core shift on the base goes the other you get what is termed worst case tolerance stack up. This effectively mis aligns the interface. If both openings were exactly the same size you would get a step up at some point on the circumference of the opening. DO NOT remove this chamfer and open the runners up as this can actually reduce airflow by increasing turbulence when the air hits a hard edge.

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Dave Zelinka

98_1LE

Phillip - Dangit, I thought the SWMG was this weekend I actually worked Saturday. I don't think your base is far behind. On the reply they told me that yours should ship next week. Let me know when you want to see them. I still haven't got the headers!

Pending Phillips advice, I only plan to open the base up to the gaskets and run a sandpaper "flapper" through the runners and base to knock the high spots down. They really are nice ports.

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87 Formula 350 13.94@96.67
98 Z28 1LE 13.15@107.59
1LE Owners Association

Matt87GTA

The solution to the misalignment issues and chamferred ports is to port match everything - plenum to runners to base to heads to headers. It is a pretty decent amount of work, but well worth it.

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Matt

1987 GTA L98 MD8 GW6

"Stop Lights timed for 35Mph are also timed for 70Mph"

98_1LE

Without tight fitting dowel pins I don't beleive that a true port match works. The reason is the parts have a small range of shift on the bolts, and any exposed lip will cause a bunch of turbulence. I think what Dave is saying is that it is better to have a slight step outward as the air passes from plenum to runner to base to heads and I agree.

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87 Formula 350 13.94@96.67
98 Z28 1LE 13.15@107.59
1LE Owners Association