350 Chevy 1.7 rockers

[VetteLT193]

Anyone use 1.7 rockers on a 350? I didn't even know they were available until recently.

I've used 1.6's in the past, as well as a split set of 1.6 intake 1.5 exhaust. both were successful upgrades over the stock 1.5's although I can't attribute how much power came from going from stock stamped rockers to rollers Vs. going from 1.5 to 1.6.

I'm thinking it could be a quick hop up, especially considering I'd like to do roller rockers anyway.

Any thoughts, opinions, etc?

http://cgi.ebay.com/ebaymotors/Chevrolet-350-400-Scorpion-Roller-Rocker-Arms-1-7-3-8_W0QQcmdZViewItemQQ_trksidZp4634Q2ec0Q2em14Q2el12 62QQhashZitem190298053721QQitemZ190298053721QQptZM otorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

[MOP]

I would be concerned about push rod clearance with 1:7's, I new a guy that ran the reverse 1:5 int and 1:6 ex shooting for a little more exhaust flow.

[VetteLT193]

I would be concerned about push rod clearance with 1:7's, I new a guy that ran the reverse 1:5 int and 1:6 ex shooting for a little more exhaust flow.

That's one of my concerns... along with a few others like the valve train geometry in general.

I also don't know if merc used roller or flat tappet on the 350 Mag. If it's not roller this is a no no regardless.

[BUIZILLA]

87-95 years were flat tappet... you gotta drill the pushrod holes for 1.6's.. I would think 1.7's ain't worth the effort, stock springs ain't gonna like that....

[VetteLT193]

I didn't think the stock springs were going to like 1.6's either so I figured new springs would be part of the mix.

If the engine is still flat tappet I'll leave it alone for now... I'm trying to think of an easy way to check to see if the prior owner updated it and am not coming up with any easy way without removing half the engine.

[BigGrizzly]

I have found that quick upgrades do not make it in the long run. Just do it right. I never had really good luck doing this because when all is daid and done you would have to get the geometry right and then with all the time etc it just isn't worth it at least to me that is.

[VetteLT193]

I have found that quick upgrades do not make it in the long run. Just do it right. I never had really good luck doing this because when all is daid and done you would have to get the geometry right and then with all the time etc it just isn't worth it at least to me that is.

I hear you loud and clear. I figured I'll do roller rockers no matter what so I may as well do them now and I'll have them for later. I thought it would be an easy job with the engine in the boat and there are zero down sides to having them...

however, now that things are not so cut and dry I'm thinking I'll do it all at once one day in the future... or talk the wife into buying a block and I can slowly build it myself.

Outdrive first though. Eddie is coming up this weekend to help me:biggrin:

[BigGrizzly]

Vette, the reason I really use roller rockers, is because both my boats have 1.7 and 1.73 rockers respectively and the Cleveland wears out valve guides because of this. so the roller tips save this issue. If there is a horse power gain, with just the rollers, at below 6,000rpms I can't see any numbers on the dyno. However wear is down. Just to clear the air. the 502 only had rollers. With the Cleveland I went from stamped steel sliders to SS full rollers, without taking it off the dyno. So take that info or don't, but that is what happened. the weird part was nothing was needed in the change, that scared me, but that was 15 years ago and it is still running.

[VetteLT193]

what you are saying makes sense and I totally agree. The main thing I've seen is some gains from going from 1.5 to 1.6's. The other is the quality of the parts... seems like some engines get a pretty good set of stamped steel rockers, others get a junky batch so it's a crap shoot if you have 'good' stamped rockers or 'just ok' stamped rockers. The full rollers at least you know are good. I have seen some engines have noticeable power gains from going to rollers and others have none... I attribute that to the wide variation of the stamped rockers but it could be other things all together (like a better valve adjustment)

The only other improvement I have personally had is noticeably lower oil temperatures, and considering it's from straight friction it has to be a good thing.

[BigGrizzly]

Agree with that. I just get carried away. But I will over engineer a crowbar.

[Choprpilot]

I switch to 1.6 Crane Gold self-align Roller Rockers in my previous SBC. They were a easy bolt on and I picked up 200 Rpm. I'm running 1.7 Crane rollers in my BBC.

[BigGrizzly]

Chop, I hope you run at least 1.7 on the BBC, because that is what it came with:biggrin.: