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Built 410 stroker looking at tunnel ram EFI setup.
Hey guys I recently picked up a replacement motor for my truck and I'd like to push it to the last mile by doing a tunnel ram dual EFI setup either fitech or holley with port injections and wanted to see why it would or wouldn't be a good idea. So a little bit about the motor, transmission and it's intended use. I got the motor from a guy who had built it to be bullet proofed and worked alongside the guys at the performance shop with over 20 years experience.
The motor is a 410 with 11.3 to 1 compression with the 220cc speed master hi port Cleveland heads. The shop that did a lot of the finer work on it and also had it's hand in the build says it should produce in the neighborhood of 500-600 hp and tq and that its good for 6500 RPMs but I'll just keep it to 5500. They also built a C6 transmission rated to handle it with a 2500 stall. What I'd like for this truck to be is a nice little weekend driver that goes fast on and off of dirt. Out of curiosity I really don't want the compression any higher, how would a tunnel ram impact that if at all? I've got some knowledge of motors but not nearly enough. Thanks!
Hey 85e thanks for replying. I have the build sheet but I'll have to find it. Once I do I'll post it here. The guy who built the motor said the cam was a flat tappet cam although I'll have to get with him on all the specifics aboutit. I really wish the motor had a roller cam in it but I think it just came down to his budget at the time. Him and I keep in touch. He really wants a video of it in the truck once I get it in there. Here's a link of a video of it running. https://youtu.be/dtVdS5gd2QE
id be interested if theres a stand alone efi that works with a tunnel ram, im buildin a 545 stroker now with a dual tunnel ram, but everything ive been reading is going towards dual carbs, and thats ok for me also as long as it gets me the best power. id even be willing to drill the ram intake to put the injectors closer to the intake ports if that is what would be needed.
Hey Skip, awesome sounding build. I've seen the single carb tunnel ram setup but not an EFI one, not to say it doesn't exist. I would imagine like you said two is better then one and allows for that extra airflow. Even coming at an additional cost I'd still go for it. The fuel ports are just something I'd like to do to assist with power response and efficiency
the thing i worry about with efi on a tunnel ram if would be somekinda computer lag between fuel delivery at idle being much further for the computer to get a reading before its burned and read by the o2 sensor in exhaust pipe. but that may not be a actual problem. most efi vehicles have the injectors really close to the combustion chambers and sometime in the chambers
My logic on the efi aspect of this is that it'll get rid of the tuning issues that comes with having a tunnel ram once properly set up and it learns the motor. I wouldn't think that the lag would be a serious issue seeing how these are designed for a wide range of applications that have many unique features but I could be wrong.
Which is also another area of concern is where to go once we've decided yes on this. Finding one for the 351m/400 has proved to be a challenge. Either that or custom fabrication then it's a matter of getting the best design input which I wouldn't know the first thing about. Let me see if I can't find that parts list today and I'll get it posted.
Thank you for another find 85e and appreciate it kopfenjager. I just found the paperwork the shop did for the motor. Let me know if there's any areas that are unclear and I can contact the original owner. Also here's a video of it being broken in https://youtu.be/dC1AuGVhhUc
Well it seems like the guy's a pro engine builder.
Camshaft is a Comp Thumpr 32-600-5 Hydraulic flat tappet. Springs will easily accommodate that cam. I like the fact that he used 3/8" pushrods.
It has a tight 107 LSA and is advanced five degrees so intake centerline is 102 degrees. It'll rumble.
A tunnel ram looks racy but it's really just a long ram manifold with the tubes going up rather than sideways. If the engine is set up right the tunnel ram will give you a boost in torque from idle on up. Tunnel rams work much better with two four barrels than with one four barrel. Two 450 Holleys, I believe List 9776, would be close to ideal. The ideal tunnel ram would be an older model with moderate sized runners, not a latest version. I think you could make two TBI units work, or else drill runners for port injection. I don't think you will gain any power with port injection over a well set up carb or TBI set. There's very little area for fuel to puddle!
With the spacers it appears the engine is set up to run 351C intakes which is good, because I don't think a 351M/400 tunnel ram would be easy to find.
I think the compression ratio will work with the heads and intake. You'll probably be buying Premium gas.
12-21-2018, 07:17 PM
