H4 Headlights
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From: Tampa, Florida
David,
>Thanks DR. I'm definitely interested in the 8" H4's, so if you can somehow put me on a "notify" list if >some become available, I'll hopefully be ready to spring into action.
Take this as your offical notification! We currently have 3 pairs in stock and Jeannie just told me the cost has gone up on the next shipment that is in route to us. After the 3 pairs in stock are gone the new price will be $269 each, sorry. :-(
>Thanks DR. I'm definitely interested in the 8" H4's, so if you can somehow put me on a "notify" list if >some become available, I'll hopefully be ready to spring into action.
Take this as your offical notification! We currently have 3 pairs in stock and Jeannie just told me the cost has gone up on the next shipment that is in route to us. After the 3 pairs in stock are gone the new price will be $269 each, sorry. :-(
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Last edited by DR; Jan 19, 2006 at 03:09 PM.
Electron Wrangler
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Dave A,
Yes you are right the H4's do come with the bulbs but not the required mounting HW.
The H4 hinge mechanism has an integrated threaded stud each side that bolts to the alloy yokes - so you the need nuts/washers for it.
(however on my H4's it was only 1/side (plus dummy locator stud) vs 2 bolts for the H5's).
I agree 2 x metric Nylock M6's in stainless is the way to go. I used 2 x stainless wave washers - but not critical. Since there is only 1/ side you want it to be a very solid connection...
Alan
Yes you are right the H4's do come with the bulbs but not the required mounting HW.
The H4 hinge mechanism has an integrated threaded stud each side that bolts to the alloy yokes - so you the need nuts/washers for it.
(however on my H4's it was only 1/side (plus dummy locator stud) vs 2 bolts for the H5's).
I agree 2 x metric Nylock M6's in stainless is the way to go. I used 2 x stainless wave washers - but not critical. Since there is only 1/ side you want it to be a very solid connection...
Alan
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From: Monroe, LA
Originally Posted by Bill Ball
Here is the procedure for US S4 and later 928s.
http://www.billsworkshop.com/P928S4/h5toh4/h5toh4.htm
I did it using a Euro donor car for the 8" H4 parts, but 928 Intl and 928 Specialists sell the new 8" H4 lamp assemblies as well.
One small issue is that the bottom post that holds the headlamp assembly, which is part of the headlamp adjustment system in Euro H4 cars, is shorter than the fixed US H5 post, and the 8" H4 headlamp assembly is dimensioned for the Euro post. So, with the longer US post, the headlamp position ends up being further forward relative to the bucket. A slot in the front edge of the bucket will fail to engage a tiny tab on the headlamp assembly that prevents the bucket from flapping in the wind, unless you swap the post assembly (good luck getting one) or do something to lengthen the tab (easy).
Other than that and the H4 electrical plug, it was plug-and-play. My compulsive description of the swap procedure makes it look harder than it is.
The H4 light pattern throws a lot more light on the road than the diffuse H5 and is a great improvement, surpassed only by the HID kits that 928 Specialists and 928 Intl also sell.
http://www.billsworkshop.com/P928S4/h5toh4/h5toh4.htm
I did it using a Euro donor car for the 8" H4 parts, but 928 Intl and 928 Specialists sell the new 8" H4 lamp assemblies as well.
One small issue is that the bottom post that holds the headlamp assembly, which is part of the headlamp adjustment system in Euro H4 cars, is shorter than the fixed US H5 post, and the 8" H4 headlamp assembly is dimensioned for the Euro post. So, with the longer US post, the headlamp position ends up being further forward relative to the bucket. A slot in the front edge of the bucket will fail to engage a tiny tab on the headlamp assembly that prevents the bucket from flapping in the wind, unless you swap the post assembly (good luck getting one) or do something to lengthen the tab (easy).
Other than that and the H4 electrical plug, it was plug-and-play. My compulsive description of the swap procedure makes it look harder than it is.
The H4 light pattern throws a lot more light on the road than the diffuse H5 and is a great improvement, surpassed only by the HID kits that 928 Specialists and 928 Intl also sell.
And thanks for the information; sorry I submitted my response before I saw yours and missed the "thanks" to you, as well. However, I have a couple of questions. Are you saying that I will (most likely) have to modify/splice my stock plug to plug into the H4's (or did I read this incorrectly)? Also, I read over your procedure, but am still "fuzzy" regarding the lengthening of the tab; can you elaborate a little? Thanks.
David
P.S. Sorry to hi-jack Darien.
P.P.S. Love the burnout, Bill!
Last edited by 1981 Shark; Jan 19, 2006 at 06:08 PM.
which wattage??
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From: Comox, BC
Standard 55/55W will work with the stock wiring. If you go higher, you should increase the wire size for the extra current by running a separate, fused circuit off of the main power terminal (jump-start terminal block), and use a relay activated by the stock connector(s).
I'm running 100/85W in my H4's, and I can actually see at night, on the hiway. I wish there was a place to mount Q4509's, like I have on the truck, but "Oh well"!
I'm running 100/85W in my H4's, and I can actually see at night, on the hiway. I wish there was a place to mount Q4509's, like I have on the truck, but "Oh well"!
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From: Buckeye, AZ
Originally Posted by 1981 Shark
Hi Bill,
And thanks for the information; sorry I submitted my response before I saw yours and missed the "thanks" to you, as well. However, I have a couple of questions. Are you saying that I will (most likely) have to modify/splice my stock plug to plug into the H4's (or did I read this incorrectly)? Also, I read over your procedure, but am still "fuzzy" regarding the lengthening of the tab; can you elaborate a little? Thanks.
David
P.S. Sorry to hi-jack Darien.
P.P.S. Love the burnout, Bill!
And thanks for the information; sorry I submitted my response before I saw yours and missed the "thanks" to you, as well. However, I have a couple of questions. Are you saying that I will (most likely) have to modify/splice my stock plug to plug into the H4's (or did I read this incorrectly)? Also, I read over your procedure, but am still "fuzzy" regarding the lengthening of the tab; can you elaborate a little? Thanks.
David
P.S. Sorry to hi-jack Darien.
P.P.S. Love the burnout, Bill!
I am not sure if the buckets on sealed beam headlights units with the chrome trim ring even have the tab. On the later car the headlight assembly has a little tab or prong-like protrusion on the lower part of the lamp, at the 5 and 7 o'clock positions. On the bucket's leading edge there is a hole that mates to the prong. This keeps the lower edge of the bucket from flapping in the wind and rubbing the fender. If you go with 7" H4's then this is not an issue. If you go with 8" and remove the chrome trim ring, I'm not sure if you need to do anything to prevent the bucket edge from flapping. I had to extend the tab/prong due to the change in headlamp assembly position. When the tab and bucket did not engage, the paint wore off the lower edge of the bucket. Others have done this on early cars. Maybe they can comment.
Last edited by Bill Ball; Jan 20, 2006 at 01:39 PM.
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From: Buckeye, AZ
Originally Posted by BrianG
Standard 55/55W will work with the stock wiring. If you go higher, you should increase the wire size for the extra current by running a separate, fused circuit off of the main power terminal (jump-start terminal block), and use a relay activated by the stock connector(s).
I'm running 100/85W in my H4's, and I can actually see at night, on the hiway. I wish there was a place to mount Q4509's, like I have on the truck, but "Oh well"!
I'm running 100/85W in my H4's, and I can actually see at night, on the hiway. I wish there was a place to mount Q4509's, like I have on the truck, but "Oh well"!
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From: Rochester, WA
Originally Posted by Bill Ball
I am not sure if the buckets on sealed beam headlights untis with teh chrome trim ring even have the tab. On the later car the headlight assembly has a little tab or prong-like protrusion on the lower part of the steel ring that hold the lamp, at the 5 and 7 o'clock positions. On the bucket's leading edge there is a hole that mates to the prong. This keeps the lower edge of the busket from flapping in the wind and rubbing the fender. If you go with 7" H4's then this is not an issue. If you go with 8" and remove the chrome trim ring, I'm not sure if you need to do anything to prevent the bucket edge from flapping. I had to extend the tab/prong due to the change in headlamp assembly position. When the tab and bucket did not engage, the paint wore off the lower edge of the bucket. Others have done this on early cars. Maybe they can comment.
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From: Boulder Creek, CA
On the '78 there is a spring that runs between the two forward, lower corners of the bucket to hold it tight against the ring or the outer lens in the case of 8". It's kind of a PITA but with long forceps(hemostat/roach clip 
) it's easy enough to get to.
) it's easy enough to get to.
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From: Phoenix AZ
Bill,
Stock H5's are 45W/65W while Stock H4's are 55W/60W (L/H)
I recommend that for anything over 80W you should upgrade those
fuses (1 per side for L & H) to 10A vs 7.5A. (@ >110W= 15A, >150W:20A)
Anything >>100W you should consider a local relay and beefier wiring. This is both to
protect the stock wiring and to get full value from the upgrade.
A 130W headlamp will drop voltage across the headlamp to relay
wiring. It will lose about 10W in stock wiring configuration. It will also be
significantly less bright than intended, and your wiring will get hot.
All in all a bad deal...
Alan
Stock H5's are 45W/65W while Stock H4's are 55W/60W (L/H)
I recommend that for anything over 80W you should upgrade those
fuses (1 per side for L & H) to 10A vs 7.5A. (@ >110W= 15A, >150W:20A)
Anything >>100W you should consider a local relay and beefier wiring. This is both to
protect the stock wiring and to get full value from the upgrade.
A 130W headlamp will drop voltage across the headlamp to relay
wiring. It will lose about 10W in stock wiring configuration. It will also be
significantly less bright than intended, and your wiring will get hot.
All in all a bad deal...
Alan
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From: Buckeye, AZ
Hmmm...I left the stock fuses alone. Wouldn't rasing the fuse level without changing the wiring be overfusing the circuit? I figured the stock fuse should be insurance againt my bulbs drawing too much. 100/85 seems fine. Anything higher, I would upgrade the wiring, relay and fuse.