Technical nailhead intake risers

Just wondering if any of you have used the risers or spacers for the Buick nailhead intake manifolds and what your opinions or experiences you can share. thanks Jack

 

check these guys out

http://centervilleautorepair.com

 

I have used spacers on lots of things. Your performance advantage depends on the rest of the engine. Port work? Lots of cam shaft? Compression?

I like an open spacer if I am trying to increase plenum size. Most stock intakes really do not like more CFM and increasing the plenum size helps in that situation.

 

Nailheads have such small valves that a riser would mostly not be effective enough to see any improvements. They are torque monsters from the factory. Mine does very well in stock configuration.......street driven, not raced.

 

Just had my 364 rebuilt with lots of stuff from Centerville. He has a lot of tech info on his website as well. If you call Russ he will be able to give you advice.


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Thanks guys, its the engine in my avatar. Its a 65 425 with an eelco 2 four intake and a pair of 500 cfm Thunder series Edlebrock carbs. I runs fine as is with good fuel mileage . Thought I might get some more bottom end as well as fill up the engine compartment a little more. I suppose what I really need to know is the negatives . thanks again. Jack

 

Russ Martin says the manifold risers actually hurt performance. A riser under the carbs is a help. Here's a quote from his nailhead web page, " About intake spacers or risers: we will not sell them because they do not work. We have found they cost you 10-15 HP and 10-15 Foot Pounds of torque! DO NOT space the intake manifold up. "

I would think a 425 nailhead would have all the bottom end you could ever want.

 

Thanks jaracer, I guess I will leave it the way it is.

 

Interesting as a 4 hole 1” spacer normally adds some low end torque or at least starts it in earlier in the rpm range where 99% of us use our cars. Not on a Buick but another torquy engine, a 4 hole 1” spacer added 10 ft pounds to an after market dual plane hi-rise manifold during extensive dyno testing at 2200 rpm right where we cruise our rides. Very interesting.....

 

Deso -

Why...I say WHY...take someone else's word for this ?
You got some Christmas money burning a hole in your pockets..?

Go out and buy a pair of 1" phenolic, four hole spacers and put them on.
1. Take careful mileage records for about a 40 mile trip on a mostly clear freeway at a given (65 to 75) speed. No hot rodding the throttle.
2. The best thing to do is a trip down your local drag strip for an accurate time slip. OR, use your phone. Download the "speed" app and use that on a open street for a little quick 600ft run...or two.
3. Install the spacers. Note that you "may" have to adjust (increase) the accelerator pumps if the engine stumbles upon a hard acceleration.
4. See #1 and #2, repeat.
The outcome is...?
Note, that an increase in ignition timing may help out either situation.

DO NOT take other people word as fact. Especially when the experiment is an inexpensive one like this. It's YOUR car, and you drive it your way, which is probably different than the next guy.
Do this experiment, learn it for yourself. You may just surprise everyone.

I can't tell you how many times I've done things to my cars that I was told..."it wont work" and found, it DID work, and work well..!
Though, as a fair heads up, it also...may not work. But at least you will know now, for yourself.

Mike

 

Then on the other hand ,,,,I guess I will try it.

 

I was eyeballing these.
Fits 400 401 425 Buick Nailhead Aluminum Riser Intake Manifold Spacer 2" Tall | eBay

 

For my 401 NH I bought the 1” spacers from that dude and am going to use them with Weiand 6x2 logs and speedway 9 super 7’s but haven’t put them on yet.

I figured it wouldn’t help performance at all mostly because the ports aren’t going to be aligned and was guessing the air would be pretty turbulent? But I just wanted to lift the logs out of the valley a bit for looks in my 32 (yeah maybe dumb who cares).

 

Yep. Who cares? If you like it, go with it. Bet itll raise some eyebrows and conversion.

 

I thought about these for my 401 build, but after talking to Matt Martin at Centerville and Tim at TA Peformance, I decided against it. One thing they both recommended though are bigger carbs. Even with 2 fours, 625 CFM each. But hey, if you don't like them, take them off. It's all about trying.