Need opinions on intake and cam and headers

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babywag
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Re: Need opinions on intake and cam and headers

Post by babywag »

Rinkle_Stinkle wrote:
Fast Eddie wrote:OK looking at the Hedman headers, the 99246 and the 99256. One is a longer tube header and the other is shorter length like the Doug Thorley. For my 79 it takes me to the 99246, but the 99256 looks like a easier install and have to get a the exhaust made either way!! Any users out there on these Hedman headers?? THX!
i just noticed that i will have to modify my exhaust to make these work.. thanx for the heads up on that. i would love to find a set that i won't have to do that on... sigh... everytime i think i thought everything out there is another issue... :ugeek:
Of course you'd have to modify the exhaust for ANY headers...kinda the whole point of installing them. To Improve exhaust flow.
I don't think anybody here is saying you NEED them, but if you want them, and like the sound, go ahead.
The driver's side manifold on late models doesn't flow as well as the early one.
The late model y-pipe is a huge bottle neck, very poorly designed. The driver's side is small, and the opening where it joins the passenger side is small.
If you stay with manifolds, get the y-pipe reworked, or preferably go with true duals.

Here's a pic...notice the driver's side entry(bottom pipe chunk in pic.) is just through that small hole.
Image

Some folks hate headers, some do not. They are proven to make a difference. Some say nothing but trouble, noisy, leak, etc.
-Tony
'88 GW (aka Babywag)
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Stuka
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Re: Need opinions on intake and cam and headers

Post by Stuka »

Yeah, the Y-pipe design in mind boggling bad.
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Pevious Jeeps: 1981 J10, 1975 Cherokee, 2008 JK, 2005 KJ, 1989 XJ
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tgreese
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Re: Need opinions on intake and cam and headers

Post by tgreese »

babywag wrote:...
Simply adding a bigger 2bbl holley is a noticeable mod.
...
My experience too. Obvious seat-of-the-pants improvement.

Free-flowing dual exhaust makes a noticeable difference as well. Not a fan of headers. Has anyone used the earlier LH V8 manifold to replace the log manifold, and successfully routed it around the driveshaft?
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
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Fast Eddie
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Re: Need opinions on intake and cam and headers

Post by Fast Eddie »

BabyWag,
Thanks for info, photo on exhaust! Much appreciated!! So I have one manifold that is bad, both have the smog pump ports! So if I can find pre-smog manifolds they would work and be an improvement to what I have on the 1979???
Rinkle,
Glad to see you are taking some of the advice/opinions....bottom line is do what you need to do and what you can afford. You will get there and this site is full of folks to offer "GOOD" advice!!

Stuka,
Thanks for this site and a great place to discuss these old JEEPS we all seem to LOVE!!!!
1979 J20, 360 w/NV4500/D300 Twin Stick/3.73 SOLD
1978 Cherokee Chief W/T Levi interior, 360 Q/T. SCRAPPED
1970 Gladiator J4800 Camper Special, Buick 350, 4spd. SOLD
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tgreese
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Re: Need opinions on intake and cam and headers

Post by tgreese »

I expect you would not see any performance difference between the manifolds with smog ports and those without. For '79 and earlier 304-360-401 there is only one manifold design, regardless of air injection ports. And you have to go way back ('73 or earlier) to possibly find manifolds with no smog ports.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.
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babywag
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Re: Need opinions on intake and cam and headers

Post by babywag »

cap smog ports and port the manifolds removing the hump inside ports.
I think SC/397 did a dyno run and there was a gain.

Either way these are choked down by poorly designed y-pipes and single exhaust.
-Tony
'88 GW (aka Babywag)
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Stuka
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Re: Need opinions on intake and cam and headers

Post by Stuka »

Fast Eddie wrote:BabyWag,
Thanks for info, photo on exhaust! Much appreciated!! So I have one manifold that is bad, both have the smog pump ports! So if I can find pre-smog manifolds they would work and be an improvement to what I have on the 1979???
Rinkle,
Glad to see you are taking some of the advice/opinions....bottom line is do what you need to do and what you can afford. You will get there and this site is full of folks to offer "GOOD" advice!!

Stuka,
Thanks for this site and a great place to discuss these old JEEPS we all seem to LOVE!!!!

70’s manifolds will bolt up to a ‘91 engine fine, but they are a different design. So they won’t bolt up to your exhaust. The reason was the switch to a drivers drop front axle.
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Pevious Jeeps: 1981 J10, 1975 Cherokee, 2008 JK, 2005 KJ, 1989 XJ
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tgreese
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Re: Need opinions on intake and cam and headers

Post by tgreese »

I understood (and parts book confirms) that only the driver's side manifold changes for 1980 with the driver's drop axle. Passenger's side design is the same for all years.

I asked above if anyone had made custom pipes and used the early style driver's side manifold on a 1980 or later. No response yet. Supposedly the later driver's side ("log manifold") is more restrictive than the early type. If you or your muffler shop were making pipes anyway, it would be an upgrade to swap the driver's side manifold.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.
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tgreese
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Re: Need opinions on intake and cam and headers

Post by tgreese »

babywag wrote:cap smog ports and port the manifolds removing the hump inside ports.
I think SC/397 did a dyno run and there was a gain. ...
Makes sense that removing the bump would help. Porting good generally. However, I wonder if he separated grinding the bump from the air injection port from porting the manifold. Maybe I will search on the mother ship.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.
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Rinkle_Stinkle
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Re: Need opinions on intake and cam and headers

Post by Rinkle_Stinkle »

wow.... 2 days of me being away from the internet and it looks like I have a wealth of knowledge dropped on me haha.

My ultimate goal is go full dual exhaust. which again I think is why I'm just going to wait on the headers. I can get a decent set later and have someone custom bend me dual exhaust for next to nothing as I have a friend with a pipe bender that owes me a few favors.

I really appreciate everyone's support.

I woke up this morning and go so excited about this build. I know I'll feel the improvement more on round to when I open up the exhaust some and upgrade from the 2 bbl carb.
1988 Grand Wag
AMC 360 with 96K
Edelbrock intake manifold
260H Comp Cam
Edelbrock AVS 4brl carb
Headman headers
2" to thrush muff with 3" tip exhaust

Fast Eddie
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Re: Need opinions on intake and cam and headers

Post by Fast Eddie »

I was talking with a longtime Jeep guy over the weekend, I asked about headers and duals and 360 torque? He advised to go with the least restricted exhaust yes, a good Y pipe does help with your low end torque, but a H pipe or X pipe helps it even more!! I have heard that and it really made me think twice about my current true dual exhaust system....! Maybe pass on the headers and modify my exhaust to get better torque......$$$ better spent!
1979 J20, 360 w/NV4500/D300 Twin Stick/3.73 SOLD
1978 Cherokee Chief W/T Levi interior, 360 Q/T. SCRAPPED
1970 Gladiator J4800 Camper Special, Buick 350, 4spd. SOLD
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dodgerammit
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Re: Need opinions on intake and cam and headers

Post by dodgerammit »

Fast Eddie wrote:I was talking with a longtime Jeep guy over the weekend, I asked about headers and duals and 360 torque? He advised to go with the least restricted exhaust yes, a good Y pipe does help with your low end torque, but a H pipe or X pipe helps it even more!! I have heard that and it really made me think twice about my current true dual exhaust system....! Maybe pass on the headers and modify my exhaust to get better torque......$$$ better spent!
I've done research on this claim (from a LS1 standpoint, but it probably is true across the board) and a properly sized y pipe, a H pipe, and a x pipe flow very similarly. We're talking 2-3 hp and 2-3 lb/ft torque difference at most.

This is a test between straight, H, and X https://www.youtube.com/watch?v=fCio5K0WfHU&t=634s I couldn't find a video of a y pipe comparison, but a good y (not restricted) will flow similarly.
84 Grand Waggy-Radio Flyer (Garnet Red/3M Ebony Metallic woodgrain, with honey interior) AMC 360 :cry: 2004 4.8LS/Advance Adapter/727/242 D44/AMC20 Serehill tailgate and headlight harnesses :fsj: Ongoing thread-viewtopic.php?t=11897

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Fast Eddie
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Re: Need opinions on intake and cam and headers

Post by Fast Eddie »

THANKS very much! Proves what I had been reading and heard too!! Not a big gain, but a gain none the less!! I agree also with the sound quality being better than straight dual pipes too! Appreciate the post!!
1979 J20, 360 w/NV4500/D300 Twin Stick/3.73 SOLD
1978 Cherokee Chief W/T Levi interior, 360 Q/T. SCRAPPED
1970 Gladiator J4800 Camper Special, Buick 350, 4spd. SOLD

jake250k
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Re: Need opinions on intake and cam and headers

Post by jake250k »

For what it's worth, Ive had really good results with hedman headers. Paid under $200 for mine from summit, installed them with supplied hedman gaskets and high temp copper permatex on both sides, and supplied bolts. I do check the bolts occasionally just in case, but they've never leaked. The one on my cj has never leaked either.

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