Author Topic: Air Gap with JayB's adapter.  (Read 2084 times)

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gregaba

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Air Gap with JayB's adapter.
« on: December 29, 2018, 11:32:50 AM »
Hi
I am ordering Jayb's 351 adapter for my 428 Monday and decided not to use my Stealth intake with it.
i was looking at Summit and read the air gap specs and instructions. They said to use the intake on the 4v heads even though it is made for the 2v heads.
My question is has anyone port matched this intake to the 4v spec?
It sounds like in the instructions that you may run into some thin walls on their intake and I don't want to ruin a new intake.
By the way Jayb's book came in yesterday and what a great book. It answered a lot of questions that I have wondered about for years and is crammed with good info. I recommend it to everyone.
Greg

jayb

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Re: Air Gap with JayB's adapter.
« Reply #1 on: December 29, 2018, 03:31:04 PM »
I ran that test on my 700 HP dyno mule.  What I found was that by port matching the Performer RPM to the intake adapter, you picked up a little top end HP, and lost a little midrange torque.  I would recommend against port matching, even though there is room in the casting.  The port mismatch doesn't seem to have much of an effect on power even on that 700 HP engine, so despite the fact that there is room to do it in the casting, I'd probably leave it along.

The thread below gives all the details.  See page 6 of the thread for the unported vs port matched test, and page 11 of the thread for bar graphs showing average torque, average HP, peak torque, and peak HP for all the manifolds tested on the adapter, on this engine.

http://fepower.net/simplemachinesforum/index.php?topic=4760.0
Jay Brown
- 1969 Mach 1, Drag Week 2005 Winner NA/BB, 511" FE (10.60s @ 129); Drag Week 2007 Runner-Up PA/BB, 490" Supercharged FE (9.35 @ 151)
- 1964 Ford Galaxie, Drag Week 2009 Winner Modified NA (9.50s @ 143), 585" SOHC
- 1969 Shelby Clone, Drag Week 2015 Winner Modified NA (Average 8.98 @ 149), 585" SOHC

   

gregaba

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Re: Air Gap with JayB's adapter.
« Reply #2 on: December 30, 2018, 04:47:32 PM »
Hi Jayb
I read the thread and was very interested in the whole thing. I was really interested in your EFI info.
I tuned a friends 302 66 Mustang that had a FAST XFI system after he had it in 5 shops and no one could make it run.
I had no experience with these new systems but I finally got it to run decent with trial and error.
Fast had no tune for his engine so I had to start from scratch.
If some one would publish a book with an explanation of what everything is and how to change the settings in a way a dummy like me could understand I would buy it.
As far as the intake for my engine I think it would run in the 425 HP range engine you tested in your book.
I was considering the Performer or Air Gap intake but after reading your post I think I will use the Torker as I have one in my shop that I used to use on my 351 Mustang.
It was interesting to me that port matching made no difference on the performer manifold. I would think with your Hi horsepower mule it would make a big difference.
I won't worry about that since My rpm range will be between 2000 and 6300.
Thanks for your help.
Greg

jayb

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Re: Air Gap with JayB's adapter.
« Reply #3 on: December 30, 2018, 05:27:25 PM »
I think the reason that port matching the Peformer RM didn't make a difference on that engine was that the small runner size up near the carb is probably the limiting factor.  So, opening up the manifold at the intake adapter didn't really overcome that restriction. 

I think the Torker will work well for you, I have one on the intake adapter on the engine in my 68 Mustang, which is a 440 HP 428CJ, and it works great.  I also like it because it is lower than the Performer RPM, so everthing fits under the flat hood of the Mustang.  You do give away some low end torque with the Torker, but I don't notice it in my car.  Look at page 20 of the thread below to see a comparison between the Torker and the Performer RPM on the engine in my 68 Mustang:

http://fepower.net/simplemachinesforum/index.php?topic=683.0
Jay Brown
- 1969 Mach 1, Drag Week 2005 Winner NA/BB, 511" FE (10.60s @ 129); Drag Week 2007 Runner-Up PA/BB, 490" Supercharged FE (9.35 @ 151)
- 1964 Ford Galaxie, Drag Week 2009 Winner Modified NA (9.50s @ 143), 585" SOHC
- 1969 Shelby Clone, Drag Week 2015 Winner Modified NA (Average 8.98 @ 149), 585" SOHC

   

gregaba

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Re: Air Gap with JayB's adapter.
« Reply #4 on: December 31, 2018, 01:18:13 PM »
Hi
I went to your link and as usual wound up reading the whole thing.
I believe I will go with the Torker as you suggested. I really liked it on my Mustang.
I am not worried about hood clearance as this engine is going into a 63 Galaxie with the bubble hood scope.
I will be running the Sniper EFI on it so that should make it a little more streetable.
Will be ordering your adp. today but with the holidays don't expect shipping today or tomorrow.
Thanks for all your quick replies to my somewhat stupid questions.
Greg

jayb

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Re: Air Gap with JayB's adapter.
« Reply #5 on: December 31, 2018, 03:54:52 PM »
Thanks Greg, I will get your adapter shipped on Wednesday - Jay
Jay Brown
- 1969 Mach 1, Drag Week 2005 Winner NA/BB, 511" FE (10.60s @ 129); Drag Week 2007 Runner-Up PA/BB, 490" Supercharged FE (9.35 @ 151)
- 1964 Ford Galaxie, Drag Week 2009 Winner Modified NA (9.50s @ 143), 585" SOHC
- 1969 Shelby Clone, Drag Week 2015 Winner Modified NA (Average 8.98 @ 149), 585" SOHC

   

gregaba

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Re: Air Gap with JayB's adapter.
« Reply #6 on: December 31, 2018, 06:12:23 PM »
You are welcome.
Greg