3.4 DOHC Cam Questions (Page 1/2)
fliphone SEP 29, 01:58 PM
Hey all! I'm currently plugging away on a LQ1 swap, and have heard rumors of people running gen 1 cams (91-95) in the gen 2 (96/97) heads as they are a more aggressive cam profile. I'm thinking a little down the road as my car doesn't run yet and I really don't need to be adding more to the list at the moment, but would like to swap the cams out if there might be some benefit to doing so. Info is scarce out there so this is kinda a shot in the dark.
TIA for any info you may have, Cheers!

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Black 88 GT, a 19 year old here about 20 years to late
-LQ1 Swap in progress-

Raydar SEP 29, 06:04 PM
The guy who built my (96-97) engine installed 93-94 cams for that reason. I'm not sure what the specs are, or whether that includes the earlier cams.
I am inclined to trust his "experience". He doesn't do stuff lightly.
fliphone SEP 29, 11:29 PM
Awesome news! Thanks Raydar!
ericjon262 OCT 02, 04:58 PM
if I remember right, somewhere in the linked thread below, the builder degreed both the early and late cams, but I don't remember for sure.

https://www.fiero.nl/forum/Forum3/HTML/000143.html

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"I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."

I invited Lou Dias to trash me in my own thread, he refused. sorry. if he trashes your thread going after me. I tried.

ericjon262 OCT 02, 05:09 PM

quote
Originally posted by Fierobsessed:

I degree'd the 96-97 cams, here they are!
code:

Intake			Exhaust
Open .006	           10	BTDC	Open .006	         122	ATDC
Open .050              -4	BTDC	Open .050	         138	ATDC
Close .006	         124	BTDC	Close .006	           12	ATDC
Close .050	         144	BTDC	Close .050	            -8	ATDC
Lift	0.37		Lift	0.37

Duration .006	246		Duration .006	250
Duration .050	212		Duration .050	214
Centerline	                 110		Centerline	                 115
Lobe Separation	112.5


And this was the 94-95 cams
code:

Intake			Exhaust
Open .006	             4	BTDC	Open .006	         126	ATDC
Open .050            -10	BTDC	Open .050	         142	ATDC
Close .006	         120	BTDC	Close .006	           16	ATDC
Close .050	         146	BTDC	Close .050	            -5	ATDC
Lift	0.37		Lift	0.37

Duration .006	244		Duration .006	250
Duration .050	204		Duration .050	214
Centerline	                 112		Centerline	                 111.5
Lobe Separation	112


To sum it up, the 96-97 Intake cams have a little more duration then the older cams. The exhaust's are nearly identical. The major difference is that the intake cam has cast in, about 5 degrees advance, and the exhaust is 4 degrees advance. So the bulk of the difference is the cam timing was changed. That's it.



https://www.fiero.nl/forum/...L/000143-4.html#p143

------------------
"I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."

I invited Lou Dias to trash me in my own thread, he refused. sorry. if he trashes your thread going after me. I tried.

fliphone OCT 03, 01:28 PM
That's a gold mine! (I think). Those look like calculations for a rocket launch to me, time to get my learn on
James G OCT 04, 05:12 PM
Does anyone knows if there is anyone making custom grind cams for the 3.4 DOHC engine?
That's interesting about the factory cams
Thanks everyone, and have a great day.
James
Raydar OCT 05, 12:41 PM

quote
Originally posted by James G:

Does anyone knows if there is anyone making custom grind cams for the 3.4 DOHC engine?
...
James



There used to be someone but by now, probably not.
You might try Delta. They do a lot of custom cams/regrinds.
BillS OCT 11, 08:24 PM

quote
Originally posted by James G:

Does anyone knows if there is anyone making custom grind cams for the 3.4 DOHC engine?
That's interesting about the factory cams
Thanks everyone, and have a great day.
James



Any established cam shop that does regrinds can offer suggestions on what will work best.

I raced one DOHC MG engine using Cosworth Ford lobe patterns, and have used various cam designs on other engines. I run an older Crane design on my 3.4 engine.
msweldon OCT 20, 11:31 AM
The 93-95 cams simply offer a little more torque in the midrange at the trade off slightly less hp up high compared to that of the 96-97 cams. There is room for another 15-30hp up top with properly reground cams and appropriate tuning as has been proven here on the board. Cam regrinding at the time was 400-500 a set. Of course wringing out that amount of additional hp higher in the rpm band does sacrifice torque in the midrange. With that said however the dyno hp curve I saw for such cams was still linear through the rpm band up to 7300rpm.