Accel says their runners are 1.65" port diameter, while the thirdgen tech articles say 1.615". Which is it?

The tech articles also say that the TPIS runners are 1.66" and the base entry is 1.75". Is this right? Nothing like blowing past a big step to kill flow.

 

Someone has told me that their Accel base measured 1.625" round, whereas the tech articles say 1.75"

 

Finally got through to Edelbrock. They claim their runners are 1.7" wide by 6.5" long.

 

Anybody want to reply?

 

I've got nothing to add, I just want to hear what everyone has to say . I'm getting ready to purchase a lower intake and I would like to know which has the largest openings as well...

 

I just got an Edelbrock base, not ported or gasget matched yet, measures aprox 1.6 inch diam at runners and 1.9 X 1.1 inches at head surface.anybody have Accel or TPIS?

 

TTT

 

I have a brand new TPIS base at my dad's shop. I'll get ahold of him and ask him to measure it tomorrow.

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My dad just measured the stock base/runners and the TPIS base/runners. Stock base is 1.525" diameter, and the runners are also 1.525". The TPIS base is 1.660", and the TPIS runners are also 1.660". Hope this helps you out.

 

I have The Accel base and SuperRam. The base itself is 1.6875 diameter at the runner openings. The openings on the runners themselves are 1.6875. But... the runners drop down to 1.625 inside. The runners flare out at the end to match the size of the base. A good idea would be to port the inside of the SuperRam runners to match the base. The base openings are 1.75 at various points.

The head intake port opening is 1.25x2inch.


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Black 90 IROC, L98, A4, 323 gear. SuperRamed 406 in the works!

[This message has been edited by MikeH (edited November 11, 2000).]

[This message has been edited by MikeH (edited November 11, 2000).]

 

Aaron...IMO From what Ive read and been told. If you want the highest flowing intake out of the box. The Accel is the one to get it costs more than the others though.

You will have to decide if its worth the extra money.



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Black 90 IROC, L98, A4, 323 gear. SuperRamed 406 in the works!

 

Where did you hear that the Accel was better? I'm not trying to flame you, but I've searched everywhere for info on the long runner high flow setups and found very little about the Accel and Edelbrock, other than the bases and the SuperRam.

Right now, I'm looking for the biggest diameter runners I can find. The AS&Ms are supposedly 1.66", the Accel claim to be 1.65" and the Edelbrock claim to be 1.7". I don't know what the real measurements are inside the runner itself.

 

I think Edelbrock casts both TPIS and Accel manifolds.They are very simaler,only difference is price.Go with the Edelbrock it is the cheapest of the 3.Add up the $$ per HP and you will see that TPIS Big Mouth is a rip at $475.And the Edelbrock is cheaper then the Accel too.

 

I form this (opinion) from the larger size of the base/runner openings. I was told by the techs at summit racing that the Accel flowed the most air. Ive read posts on the Corvette forum from people who say they have seen them tested and the Accel flowed the most air. I dont have any flow data on the Edelbrock or TPIS base to compared to. Maybe someone else does?

Out of the Box the AS&M runners flow the most air 260cfm. Thats speaking of the non siamesed type runners. They have the largest runner diameter also and are the longest. I had an old CHP mag that had alot of info Im quoteing from it. It seems when you go to a longer runner you need more diameter. Shorter runners seem to have a smaller diameter.

The Accel runners flow 242 cfms out of the box. I have these runners on my car now and IM very please with the performance. Although the AS&M runners flow more air than the out of the box Accels. What you by is what you get with the AS&M runners. The Accel can be ported to out flow the AS&M runners.

I dont know anything about the Edelbrock Runners. I do think they have some of the best products.

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Black 90 IROC, L98, A4, 323 gear. SuperRamed 406 in the works!

 

I am so leary of those commonly posted flow numbers. A flow bench is a complicated device that has to be run and maintained by a real professional. It also cannot simulate real engine operation. Those flow numbers are worth exactly what we paid for them. Also, everyone touts the AS&M runners because they are made of tubing and are smooth inside. Flow is actually worse on a smooth, highly polished surface IMO - and I'm not refering to lack of turbulence for "wet" manifold applications.

Anyway, I'm tyring to find my best option. By manufacturer claims, the Edelbrocks are the biggest. Magazines claim the AS&M flow the best. I trust neither. I also wonder if the Edelbrocks and Accels hold their diameter throughout the runner length.

 

I had a Magazine quite a few years ago. That did a dyno shootout testing the different runners. They listed the torque/horsepower, diameters,and lengths. I looked thru all my stuff and I can not find it.

The AS&Ms stick in my mind as having the best looking curves. If my memory is correct they had the largest diameters, and the longest length also.

I like the cast runners because you can port them out alot if you need to. I dont see where you could go wrong with any of them.

I understand what you are saying about the flow numbers. Ive seen quite a few different numbers from the same heads. Even with the same type of flow bench and test pressure. you are right.. Total system flow is the key from the TB to the cylinder.

Good luck with your purchase!

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Black 90 IROC, L98, A4, 323 gear. SuperRamed 406 in the works!