If you have a GT-40 intake and need to go with a 1" phenolic spacer READ

2FastLX · 07-16-2001, 12:54 PM

I didn't think to check before slamming my hood after installing the 1" phenolic spacer and put a couple marks on my GT-40 intake with my hood

So, to remedy the problem I went to a local junk yard and found a scoop off of an older Capri (my car is a 90 LX). I just got back in from installing it and I think it's going to look pretty d@mn good considering what it came off of. I'll be getting a Cervini's before too long so it's just a temporary fix, but I think I could get pretty used to this hood for now

Anyone else ever do this?

------------------
Gunning for 12's!

Buy your parts here
ICQ# 42269241

Timanator · 07-16-2001, 10:34 PM

I have installed 1 inch spacers on Fox bodies with stock hood with GT 40 and Cobra intakes both with no problems.
Sorry to hear about your mishap. Not sure why your intake would stick up that far.

MiracleMax · 07-17-2001, 11:45 PM

Just curious? why are you running a 1" spacer?

Any time you lengthen the the runners, it shifts the torque peak lower in the RPM range (I guess with the stock cam this might not be a problem). If the GT-40 has a comparable runner length to the stock manifold then this might sap some power off the top end (how much I couldn't say?) If the GT-40 has a shorter runner length then things might end more or less even or skewed in favor of a stock cam?

I've got a phenolic spacer on a carbed engine and its about 7/16" to 1/4" thick and does a bang up job of insulating the carb from the manifold. (I would say the manifold is in the 120 to 150 degree range and the carb is barely over 100 degrees when the manifold is to hot to touch).

A 3/8" thick spacer would probably provide similar insulating benefits without altering the tuned aspects of the manifold as much.

dinomite · 07-17-2001, 11:53 PM

I've always wondered if you would pick up any torque by doing that. do you get much power from the cooling effect?

Mike Souslin · 07-18-2001, 12:04 AM

I have a 1" spacer on my car also but it was out of necessity for me. With my heads I had to use the spacer for the upper intake to clear the rocker covers! I do have a very small dent in my hood from where the TB is hitting it when the motor torques over!
The cowl hood will solve this problem in the future!

------------------
91 Coupe with fresh rebuild. Running Stage 2 Avenger heads (51cc chambers), Stage 2 cam (.549, .566)1.7 Crane Gold Race rockers, Port matched GT-40 upper & lower, 75mm Bullet MAF, 65mm Accufab TB, MSD 6AL, Long Tubes through off road and Dynomax muffs. Stock T-5 and 3.73 gears. Big Blue Bottle on it's way!!!
Best time so far = 60'=2.021, 1/8=8.366 at 86.37 mph and the 1/4 was 12.926 at 108.94mph.

2FastLX · 07-18-2001, 12:17 AM

I am running the 1" spacer just so I can use the Ford Racing tall polished valve covers. Yeah, it did shift my torque curve lower in the RPM range, but it's all good because it seems to run a little stronger now.

------------------
Gunning for 12's!

Buy your parts here
ICQ# 42269241

MiracleMax · 07-18-2001, 12:20 AM

Whats the rule of thumb? for every 10 degree drop in temp you gain 1 hp or something like that?

The problemo with modern fuelie systems is that by placing the fuel metering device right at the intake port you lose the latent cooling ability that gasoline exhibits when changing from a liquid to a vapor. Hence the reason why on two identical engines running the same intake manifold flowing the same air through the manifold, the carb will almost always out power the fuelie manifold on the top end. The engine is recieving a denser charge of A/F compared to the injected set-up, but thats purely academic. Toss in things like uneven fuel and air distribution, and the injected intake becomes more attractive. since it at least provides superior fuel distribution compared to the carbed unit which meams more torque at all the points until the carbed intake is moving air sufficiently fast enough to keep things sorted out.

But I digress

anywhosit, the longer you can keep the intake charge cooler, the denser it will be when it enters the combustion chamber (case in point slap a bag of ice on your intake manifold and jump in the car. Its like slapping on a set of underdrive pullies!) On a GT-40 it might not be to bad, but a stock intake or any of the cast aluminum intakes has a large amount of metal to absorb heat with making them into little ovens. Anything you can do to insulate the upper from the lower will help power.

As for adding torque, you aren't really adding any, rather by extending the runners, you lower the point at which resonant tuning occurs (ram tuning as its probably better known). Pumping up the torque down lower making it a bit peakier IMO if the manifold in question has been optimized for the engine.

After doing some math if I remeber correctly, adding 2-1/2" to 2-3/4" of length to a Vic 5.0 efi manifold drops the peak power range by about 1,000 rpm Dont take this relationship to be the same for every runner length, displacement, and engine speed. Typically at lower engine speeds longer runner lengths are needed to produce similar results (if I remeber correctly)

07-16-2001, 12:54 PM	#1
2FastLX The Photoshop Guru Join Date: Feb 2001 Location: Mecca, Indiana Posts: 1,419	If you have a GT-40 intake and need to go with a 1" phenolic spacer READ I didn't think to check before slamming my hood after installing the 1" phenolic spacer and put a couple marks on my GT-40 intake with my hood So, to remedy the problem I went to a local junk yard and found a scoop off of an older Capri (my car is a 90 LX). I just got back in from installing it and I think it's going to look pretty d@mn good considering what it came off of. I'll be getting a Cervini's before too long so it's just a temporary fix, but I think I could get pretty used to this hood for now Anyone else ever do this? ------------------ Gunning for 12's! Buy your parts here ICQ# 42269241

07-16-2001, 10:34 PM	#2
Timanator Registered Member Join Date: Apr 2000 Location: Houston TX Posts: 42	I have installed 1 inch spacers on Fox bodies with stock hood with GT 40 and Cobra intakes both with no problems. Sorry to hear about your mishap. Not sure why your intake would stick up that far.

07-17-2001, 11:45 PM	#3
MiracleMax Registered Member Join Date: Apr 1999 Location: Hayes, Va, USA Posts: 798	Just curious? why are you running a 1" spacer? Any time you lengthen the the runners, it shifts the torque peak lower in the RPM range (I guess with the stock cam this might not be a problem). If the GT-40 has a comparable runner length to the stock manifold then this might sap some power off the top end (how much I couldn't say?) If the GT-40 has a shorter runner length then things might end more or less even or skewed in favor of a stock cam? I've got a phenolic spacer on a carbed engine and its about 7/16" to 1/4" thick and does a bang up job of insulating the carb from the manifold. (I would say the manifold is in the 120 to 150 degree range and the carb is barely over 100 degrees when the manifold is to hot to touch). A 3/8" thick spacer would probably provide similar insulating benefits without altering the tuned aspects of the manifold as much.

07-17-2001, 11:53 PM	#4
dinomite The Dude Join Date: Feb 2001 Location: Arlington, VA Posts: 1,262	I've always wondered if you would pick up any torque by doing that. do you get much power from the cooling effect?

07-18-2001, 12:04 AM	#5
Mike Souslin Registered Member Join Date: Sep 1999 Location: Grove City Ohio Posts: 226	I have a 1" spacer on my car also but it was out of necessity for me. With my heads I had to use the spacer for the upper intake to clear the rocker covers! I do have a very small dent in my hood from where the TB is hitting it when the motor torques over! The cowl hood will solve this problem in the future! ------------------ 91 Coupe with fresh rebuild. Running Stage 2 Avenger heads (51cc chambers), Stage 2 cam (.549, .566)1.7 Crane Gold Race rockers, Port matched GT-40 upper & lower, 75mm Bullet MAF, 65mm Accufab TB, MSD 6AL, Long Tubes through off road and Dynomax muffs. Stock T-5 and 3.73 gears. Big Blue Bottle on it's way!!! Best time so far = 60'=2.021, 1/8=8.366 at 86.37 mph and the 1/4 was 12.926 at 108.94mph.

07-18-2001, 12:17 AM	#6
2FastLX The Photoshop Guru Join Date: Feb 2001 Location: Mecca, Indiana Posts: 1,419	I am running the 1" spacer just so I can use the Ford Racing tall polished valve covers. Yeah, it did shift my torque curve lower in the RPM range, but it's all good because it seems to run a little stronger now. ------------------ Gunning for 12's! Buy your parts here ICQ# 42269241

07-18-2001, 12:20 AM	#7
MiracleMax Registered Member Join Date: Apr 1999 Location: Hayes, Va, USA Posts: 798	Whats the rule of thumb? for every 10 degree drop in temp you gain 1 hp or something like that? The problemo with modern fuelie systems is that by placing the fuel metering device right at the intake port you lose the latent cooling ability that gasoline exhibits when changing from a liquid to a vapor. Hence the reason why on two identical engines running the same intake manifold flowing the same air through the manifold, the carb will almost always out power the fuelie manifold on the top end. The engine is recieving a denser charge of A/F compared to the injected set-up, but thats purely academic. Toss in things like uneven fuel and air distribution, and the injected intake becomes more attractive. since it at least provides superior fuel distribution compared to the carbed unit which meams more torque at all the points until the carbed intake is moving air sufficiently fast enough to keep things sorted out. But I digress anywhosit, the longer you can keep the intake charge cooler, the denser it will be when it enters the combustion chamber (case in point slap a bag of ice on your intake manifold and jump in the car. Its like slapping on a set of underdrive pullies!) On a GT-40 it might not be to bad, but a stock intake or any of the cast aluminum intakes has a large amount of metal to absorb heat with making them into little ovens. Anything you can do to insulate the upper from the lower will help power. As for adding torque, you aren't really adding any, rather by extending the runners, you lower the point at which resonant tuning occurs (ram tuning as its probably better known). Pumping up the torque down lower making it a bit peakier IMO if the manifold in question has been optimized for the engine. After doing some math if I remeber correctly, adding 2-1/2" to 2-3/4" of length to a Vic 5.0 efi manifold drops the peak power range by about 1,000 rpm Dont take this relationship to be the same for every runner length, displacement, and engine speed. Typically at lower engine speeds longer runner lengths are needed to produce similar results (if I remeber correctly)