Straight or Angled Plug Heads? Engine Questions.
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From: Lenoir City Tennessee
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St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15
Straight or Angled Plug Heads? Engine Questions.
Why choose one over the other? I was looking at the Trick Flows and the Worlds Sportsman II. The TF come with angled plugs but you can get the Worlds either way. Which is better.
I am going to be rebuilding the 350 in my 70 model and want a performance increase. The car has a 3.36 rear and 4 speed. I want a reliable cruiser that is not gonna lay down on me. Something that will run strong when I want it too. I am thinking I want a Comp Cams Xtreme cam but not sure of which. I talked with one who has a XE274 that he likes.
Also the intake must fit under the hood of my 70. One of the Edelbrock Air Gaps is said to fit by one of the other members.
I know these questions have been asked before, but any help would greatly appreciated.
I am going to be rebuilding the 350 in my 70 model and want a performance increase. The car has a 3.36 rear and 4 speed. I want a reliable cruiser that is not gonna lay down on me. Something that will run strong when I want it too. I am thinking I want a Comp Cams Xtreme cam but not sure of which. I talked with one who has a XE274 that he likes.
Also the intake must fit under the hood of my 70. One of the Edelbrock Air Gaps is said to fit by one of the other members.
I know these questions have been asked before, but any help would greatly appreciated.
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Re: Straight or Angled Plug Heads? Engine Questions. (Eddie 96)
For what you're doing it won't make much difference.
The original intent of the angle plugs when they were offered as an over the counter Hot Rod part or a head was modified for them was to help the flame front get over the large domes in old super high compression engines. It also helped position the plug in a spot where it was able to not get "drowned" as well as kept plug from getting smacked by the piston dome.
It was often used with "fire slots" in the piston dome to allow better burning. It all was a tremendous deal when running super tight chambers and 13.0 compression.
You see it these days combined with the new fast burn combustion chambers to place the plug in the area they have spent so much time using swirl to position the mixture in the chamber.
So in 99% of street applications you won't see much difference. What you have to be real careful of is header clearance with angle plugs. Many headers don't fit them very well, and you end up having to dent tubes etc to clear the plugs and wires. You will notice some power issues there if it becomes too excessive. Plus plug wires get burnt real bad if the headers are poorly designed for the angle plugs.
Jim
The original intent of the angle plugs when they were offered as an over the counter Hot Rod part or a head was modified for them was to help the flame front get over the large domes in old super high compression engines. It also helped position the plug in a spot where it was able to not get "drowned" as well as kept plug from getting smacked by the piston dome.
It was often used with "fire slots" in the piston dome to allow better burning. It all was a tremendous deal when running super tight chambers and 13.0 compression.
You see it these days combined with the new fast burn combustion chambers to place the plug in the area they have spent so much time using swirl to position the mixture in the chamber.
So in 99% of street applications you won't see much difference. What you have to be real careful of is header clearance with angle plugs. Many headers don't fit them very well, and you end up having to dent tubes etc to clear the plugs and wires. You will notice some power issues there if it becomes too excessive. Plus plug wires get burnt real bad if the headers are poorly designed for the angle plugs.
Jim
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From: Twin Cities Minnesota
Re: Straight or Angled Plug Heads? Engine Questions. (427Hotrod)
I bought angle plug heads and I wish I hadn't. It's a real pain and I've since found out that there is no real performance gain unless you're looking for that last 1/2 HP:(
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From: Lenoir City Tennessee
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Re: Straight or Angled Plug Heads? Engine Questions. (427V8)
Thanks for the responses guys. Anyone know of any thing else to look for. I am gonna pull this thing this weekend so I can get at the front suspension and I may as well start ordering parts sometime.
[Modified by Eddie 96, 4:36 PM 1/22/2002]
[Modified by Eddie 96, 4:36 PM 1/22/2002]
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Re: Straight or Angled Plug Heads? Engine Questions. (Eddie 96)
The other view point.
I'm a firm believer in angle plugs for all SBC's. Even in the modern high swirl enviroment nearly all high end heads are angle plugs. The plug placement has lots to do with ping and detonation resistance. Angle plugs also have the advantage of using the longer 3/4 inch threading so the plugs are subjected to less heat changes. the extra casting metal maintains a more constant heat - so picking the right range of plug is easier.
When I had straight plug heads I think i had about 3 plugs that I had to change from under the car once I went to angle only one is hard to get at.
I'm a firm believer in angle plugs for all SBC's. Even in the modern high swirl enviroment nearly all high end heads are angle plugs. The plug placement has lots to do with ping and detonation resistance. Angle plugs also have the advantage of using the longer 3/4 inch threading so the plugs are subjected to less heat changes. the extra casting metal maintains a more constant heat - so picking the right range of plug is easier.
When I had straight plug heads I think i had about 3 plugs that I had to change from under the car once I went to angle only one is hard to get at.
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From: Orange Park Florida
Re: Straight or Angled Plug Heads? Engine Questions. (gkull)
gkull, I would have to agree with you on that header/changing plugs thing...
I have two sets of headers here now, differant designs, and another post about them for comparison purposes...and in either set , the angle plug would make plug changing easier....NOT harder....I had to ding the 'strange looking' set of larger tube headers to clear the straight plugs I have on my Edel heads...they are 1.75 inch tubes so I figger it's no loss....
GENE
[Modified by mrvette, 3:07 AM 1/23/2002]
I have two sets of headers here now, differant designs, and another post about them for comparison purposes...and in either set , the angle plug would make plug changing easier....NOT harder....I had to ding the 'strange looking' set of larger tube headers to clear the straight plugs I have on my Edel heads...they are 1.75 inch tubes so I figger it's no loss....
GENE
[Modified by mrvette, 3:07 AM 1/23/2002]
Drifting
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Re: Straight or Angled Plug Heads? Engine Questions. (Steve Straus)
I am running a 388ci stroker motor and I am very pleased with my angle plug Trick Flow aluminum heads. I have Hooker 1 7/8 in sidepipe headers on them and have good plug clearance.
Neil in Tenn
Neil in Tenn
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Re: Straight or Angled Plug Heads? Engine Questions. (Eddie 96)
Eddie-
I just finished putting Trick Flow 23 deg heads and Dynomax ceramacoat headers on this weekend. I got the angle plugs, and there are no clearance problems with the headers and plugs.
:cheers:
I just finished putting Trick Flow 23 deg heads and Dynomax ceramacoat headers on this weekend. I got the angle plugs, and there are no clearance problems with the headers and plugs.
:cheers:
Melting Slicks
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Re: Straight or Angled Plug Heads? Engine Questions. (Eddie 96)
I've had TFS heads before and currently have Sportsman II's. Both angle plug. The angles on these two sets of heads are different. With TFS and Hedman headers I had no plug clearance problems. With the S II's and Hedman I had problems with 4 of 8 plugs. Currently with the S II's and Hooker sidepipes I have no plug clearance problems. So, it depends on what headers you plan to use with what set of heads.
Burning Brakes
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From: Saskatoon Saskatchewan Canada
Re: Straight or Angled Plug Heads? Engine Questions. (nastee383)
As many may remmeber I was going to buy the hooker side pipes and hooker's web site says they won't fit on angle heads. Well most of the answers said only one or two plugs were the problem. I have GM034 heads. and after installing the headers I say it's not a big issue. 
[Modified by paso, 8:03 AM 1/23/2002]
[Modified by paso, 8:03 AM 1/23/2002]
Burning Brakes
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From: Madison MS
Re: Straight or Angled Plug Heads? Engine Questions. (paso)
Hey Paso, is it me or do you have an oil pan gasket problem there. Looks like the bow in the gasket for the dipstick is on the wrong side of the engine.
dl
dl
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Re: Straight or Angled Plug Heads? Engine Questions. (dladd74roadster)
Thanks for all the replies.
Angled it is. And TFS 23 degree.
Will get to order in the next day or so.
Owww my credit card is begining to ache. :lol:
Angled it is. And TFS 23 degree.
Will get to order in the next day or so.
Owww my credit card is begining to ache. :lol:
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Re: Straight or Angled Plug Heads? Engine Questions. (Eddie 96)
Eddie,
Putting a RPM or Air Gap RPM under a hood like yours will require milling the choke tower off a Holley carb to maintain 1 inch or so clearance between the carb and the filter top.Too close for me and makes a Qjet out of the question.Yes one of the members is running a Air Gap with a hot cam ect.It is a new combo and the RPM is falling off at 5k.I wonder why?The Performer can and will make great power with everything else in order combination wise.I don"t know what carb you are wanting to use but thought I would bring this up now,not after the fact.I know for a fact they will support 400hp.Maybe more.
If need be for a little more top end power one could modify the center divider to near Air Gap Specs
[Modified by mountainmotor, 7:41 PM 1/24/2002]
Putting a RPM or Air Gap RPM under a hood like yours will require milling the choke tower off a Holley carb to maintain 1 inch or so clearance between the carb and the filter top.Too close for me and makes a Qjet out of the question.Yes one of the members is running a Air Gap with a hot cam ect.It is a new combo and the RPM is falling off at 5k.I wonder why?The Performer can and will make great power with everything else in order combination wise.I don"t know what carb you are wanting to use but thought I would bring this up now,not after the fact.I know for a fact they will support 400hp.Maybe more.
If need be for a little more top end power one could modify the center divider to near Air Gap Specs
[Modified by mountainmotor, 7:41 PM 1/24/2002]
Burning Brakes
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From: Saskatoon Saskatchewan Canada
Re: Straight or Angled Plug Heads? Engine Questions. (dladd74roadster)
No it's the new felpro one piece gasket that fits engines with the dipstick on the other side.:) they have it on both sides It's well sealed . Needs to be trimmed yet. I told a friend when he asked that it was a "trouble light hanger " and that they think of everything these days :D :D
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Re: Straight or Angled Plug Heads? Engine Questions. (mountainmotor)
Folks - beware that when someone says an Edelbrock AirGap manifold that there are now TWO of these - the RPM airgap and the Performer AirGap.
I have the PERFORMER AIRGAP, small block, small block hood, Edelbrock 1405 600cfm carb.... it all fits. See:
I just posted by dyno info a few minutes ago too -
Jim
I have the PERFORMER AIRGAP, small block, small block hood, Edelbrock 1405 600cfm carb.... it all fits. See:
I just posted by dyno info a few minutes ago too -
Jim
