Need urgent advice timing an 84 351W... There is something strange going on

Tiha

Active member
Staff member
Moderator
Joined
Jul 22, 2020
Messages
340
Reaction score
242
Location
Midwest
Yeah kinda sounds like a timing chain check. If it was one tooth off it could still run decent and your timing marks off.

We used to advance the chain by one or two teeth to advance the cam, it would lower the operating range of the camshaft. Most guys wouldn't notice unless they were racing or towing a lot. It was the only real way to notice the difference.
On a small block chevy I am thinking one tooth was 2 or 2.5 degrees of camshaft timing.
So if someone got a camshaft with a ideal rpm range of 4000-8000 rpms, advancing it would bring the range down to maybe 1500-6000 rpms instead.
Poor mans performance. We used to pick up used race car cams at the swap meets for $5. Throw it in and make the best of it.

In the 70's Ford used to ****** the cam timing on the big engines like the 460 so it would run better at higher rpms, like 75 on the interstate. Advancing the cam timing really woke the engines up, made them much more responsive, but of course high end hp and mileage suffered.
 

johnnyreb

Well-known member
Joined
Feb 23, 2021
Messages
1,008
Reaction score
397
Location
West Virginia
That,s bad. This junk from China is sad. I,m goin through about the same -in the last few years. Good luck.
Try timing it top dead center(forget about 10 degree for now) and AND check the distributor on top dead center. Try it and see what it does. Then if it needs to turn the distributor to 10 degrees . Turn it.
 

johnnyreb

Well-known member
Joined
Feb 23, 2021
Messages
1,008
Reaction score
397
Location
West Virginia
That,s bad. This junk from China is sad. I,m goin through about the same -in the last few years. Good luck.
My cousin went the 5 Jasper motors before he finally got a good one. Now after the second one.I would have made them return my money and went some place else.
 

johnnyreb

Well-known member
Joined
Feb 23, 2021
Messages
1,008
Reaction score
397
Location
West Virginia
Brand new engine with less than 3000 miles with new harmonic balancer installed at installation time.
Something else you might want to check. When IF you take the timing chain off. Check the cottor that hold the harmonica IN LINE . Is it steel or aluminium? Aluminium can snap off. or twist part way and knock your timing off. Its easy to over look someting. Especially if some one is talking to you.When you are trying to do something. Did you get it running right? Let us know one way or the other and it might help some one else.
 
Joined
Sep 19, 2016
Messages
50
Reaction score
17
I reported that I have done the timing to TDC of plug 1 compression ****** and rotor points to number 1 position on dist cap as expected. This bronco valve cover says timing to 10 btdc and so I mark that on HB. Next I start the truck but it's a hard start with low vacuum. Once started, I turn the dist left to get best performance and vacuum at 20 in/hg. Here, the timing light shows the 10 btdc mark on HB flashing near the half circle notch of the timing pointer. Normally this timing mark would flash at the timing pointer position. I have the Bronco running and starting great but I've run out of time to play with it and will see about the timing chain or harmonic balancer later on.

It's getting close to winter time here in Maine and I live off grid up on a granite mountain top with a half mile long driveway so it's time to cut and process ash firewood. Luckily, I have a 2005 Ford F350 Super duty V10 dually with a dump body that only has 28,000 miles on it. I starts on one crank and is a badass plow truck with a Fisher VX2 9.6' plow.
 

Attachments

  • image0-2.jpeg
    image0-2.jpeg
    577.4 KB · Views: 1

Members online

Forum statistics

Threads
21,746
Messages
128,183
Members
23,916
Latest member
RJobe
Top