Hello,

Ive got an 87 K5 with a swapped 400 in it.

I recently was replacing gaskets and doing a tune up on the engine, since I just bought it, and I got it all back together and I heard a reallly loud tapping, and thought, well there goes this engine. But after close examination with a screwdriver, the noise was coming from the distributor cap.

The rotor is hitting the inside of the cap. I took off the cap, which was brand new, and the plastic parts jutting out from the inside are scraped up pretty bad. It is the identical rotor and cap that I took off.

The truck does have the coil on top of the cap.

How do I fix this tapping. Can someone link me to the proper distributor cap so I can make sure mine is correct?

Also, when I put the cap on, it doesnt seem to fit on there straight, making me think I have the wrong cap. When I try to clip down the back right bolt (closest to the firewall), it is practically impossible to clip down. Something just doesnt seem right but I dont know how to fix it.

Can I just sand down the inside of the cap and get those plastic pieces off so the tapping will stop?

Heres a video of the tapping, so you can hear how loud it is.

http://www.youtube.com/watch?v=sRntrivJh_o

Thanks.

 

hmmm kinda makes me wonder if this is a mismatched distributor/cap... or possibly the wrong setup.... nice video btw but is there any chance of getting a pic or something of the cap? and distributor?
cuz in my mind a 400 distributor looks like this
http://www.summitracing.com/parts/MSD-8416/?rtype=10

is this what yours looks like? i have seen instances where a brand new cap and rotor hit like yours... and it was a faulty mold on the plastic...
any idea on what year the motor is? because they quit putting 400's in the K5 in 1980.. and yes i know yours is a newer k5 with a retrofit 400 in it.. any info you can get on that motor will help us... help you

i guess i should of asked, if your 100% sure its a chevy 400? and not a pontiac or something like that also??? just a afterthought

Ck1500

 

Sounds like you have a typical HEI distributor. You didn't happen to put the rotor on backwards or not get the alignment pin in its proper location did you?

 

Yea I was wondering as well if it was a mismatched setup. The guy I bought it from didnt have a screwdriver to his name...so he was no help in telling what the motor came out of or what year it was.

I've looked all over for the casting number and still cant find it, so all I can really say is its a 400, according to him. So honestly I could say I am not 100% sure whether it is a 400 or not.

Here are some pictures of the setup, hopefully they help...

Old One on top















Any help is appreciated...thanks!

 

Sometimes it can be difficult to get the distributor cap to sit properly onto the base of the distributor. This is especially true on lifted trucks (never had an issue with this on my Chevelle).

I am wondering if you may have not gotten either the cap or the rotor fully seated into its proper position which may have caused the collision...

 

Yea that could definitely be it. I am taking off the fender today(it needs replacement), so once I take that out I will be able to walk right into the engine compartment and make sure it is set right.

I also want to mention the engine did have a tap before, when I first got it, but I took that to be a valve or something, but I wonder if it was the distributor cap as well? The old distributor cap had a spot carved out too for the rotor to spin. Which really makes me wonder if I have the correct cap.

Thanks.