72delta88

I'm trying to figure out if my 1972 delta 88 350 has an aftermarket cam it has a mildly lopey idle and its noticeable even with stock exhaust if the cam may be stock it might be about time for a timing chain since I'm unsure about the cam or chain it has 105k on it

MDchanic

When you open it up to change the timing set, you'll be able to see whether the cam has the factory chamfers on the end.

- Eric

72delta88

the only reason I think its been changed is it pulls hard through 6500 how hard is the chain to do in the car

Fun71

I would not run the engine up that high if I was unsure of the integrity of the timing chain.

MDchanic

If it will rev to 6,500 RPM, the cam has been replaced.

Are you sure your tachometer is accurate?

It's not the timing chain that you need to worry about (though they do stretch), it's the cam sprocket, whose nylon teeth disintegrate, creating slop and the possibility of the chain jumping a tooth, which would probably be the end of that engine at 6,500 RPM.

No harder to change than any other: pull front accessories, pull water pump, pull damper, remove cover.

- Eric

Cutlass Fan

Is this with the Holley carb on the 2 bll manifold with the adapter? If it is I would doubt that it would "pull hard to 6500" as I doubt any 2 b manifold would flow enough to support that kind of rpm.

72delta88

amazingly yes it is I would have to agree it shouldn't pull that hard on that intake

MDchanic

Ha ha. Good point. I hadn't connected the two threads.

Back to my question about the tach.

Thanks!

- Eric

72delta88

Cutlass Fan

I think your tach is VERY optimistic lol.

72delta88

I'm goin to get a timing light with a digital read out later I think my bosch tach an my msd box aren't liking eachother

76olds

When I read your other post you mentioned backfiring up through the carb. I was thinking a wiped cam lobe at the time but didn't post, but you said the cam was swapped out. I'm surprised to hear that now it could be the chain. Too many threads going here, unless I'm the only one getting mixed up between threads and the supplied information.
Eric

76olds

Why would you want to run it up to 6500 rpm, holy jumpin' its a delta 88. You using rocket fuel in that beast.
Eric

72delta88

tachs reading way high

72delta88

got it fixed the tach was reading way high the msd box doesn't like the tach
I got the timing fixed its dead on the dizzy got loose and turned on me

MDchanic

Really?

How high was it revving when you thought it was revving 6,500?

How does this affect the answer to the initial question you posed here, ie: Do you have an aftermarket cam?

- Eric

72delta88

my rev limiter kicks in at 4800

MDchanic

Much more realistic.

Thanks!

72delta88

I just went out an checked the msd box limiter my neighbor looked at me like I was nuts

76olds

Does your neighbour like nuts ? Maybe he's got the munchies haha.

72delta88

haha he a d..k so I wont be surprised to get the cops called for the 88 backfiring

76olds

Don't give up on your Olds, the guys here are always willing to help give you the information needed to get your Olds running. Get a few tools together that will help you trouble shoot the things that others post.
You'll have it running good in no time. Its good to see young guys like yourself driving Oldsmobiles!!
Put-er-ther you'll learn alot here, just be patient and learn as you go.
Cheers
Eric

72delta88

I got it adjusted to 8 degrees initial and I think 26 advance its running great I may swap to a 403 though

olds 307 and 403

I would advance it another 2 to 4 degrees, low compression Olds V8's love a lot of timing. Also get a Performer or RPM intake in place of that ridiculous adapter. A 403 with your current 350 heads and an upgraded cam would be night and day.

72delta88

that's exactly what I'm thinking the owners holding the 403 for me so I can pick it up in December its 200 well spent