mnorton

Has anyone used their stock 305 center bolt valve covers on a set of SR Torquers? Do they leak oil?

I read that you have to grind the perimeter bolt bosses away to use center bolt covers.
I also read that center bolt covers don't work well with these heads.

Also did you drill the hole for the EGR valve? Any issues with that?

I have an 87 305 TPI setup and a set of SRT's shipping to California next week.

kidcamarosc

Not sure why this is on the prom board. I have those heads and actually bought some nice $100 GM Performance centerbolt valve covers to put on only to find out it would not work. The holes for the old style covers make it so the centerbolt covers will not sit down all the way on the heads.

mnorton

On the PROM Board?... I think I posted in the general TPI board...

Back to the SR's... I read that you can grind away a portion of the perimeter bolt bosses and then use center bolt covers. Still I get the feeling that center bolt covers just are'nt going to fit those heads. I guess that's what you have experienced....

I'd like to keep the engine looking as stock as possible. Do you know of a good "stock-like" perimeter valve cover?

Tony89

I bought a set of those about 6 months ago believing that I would have a mountain of machine work to do before I could install them. Specifically the EGR issue, grinding the perimeter bolt bosses, etc. I was pleasantly surprised to find that:

1. The EGR crossover was already drilled.

2. The perimeter bolt bosses were already ground down.

3. The only machine work I had to have done was to have the rocker arm mounting pads shaved for the thickness of the guideplates I was going to use, and have the pushrod guide holes hollowed out to avoid the double-indexing problem. This may not be necessary if you're not going to use roller rockers.

The part # I purchased was 042750-1 for later model engines. This may differ on the heads set up for earlier third-gens.

A word on stem-seals. They use nitrile umbrella type seals. Apparently, nitrile is the cheapest material there is for this purpose. Conveniently, the valve guide bosses are machined for positive stop type stem seals (my caliper measurement was somewhere between .530 and .532 inches. I plan on purchasing some of these from Summit or Jegs before installing these heads. I have that infamous and annoying puff of light blue smoke on start-up sometimes indicating worn stem seals and the last thing I want to do is to go to all of this trouble only to have the new seals be "less than the best."

mnorton

Thanks for your input.

Tony89,
I'm surprised that the EGR passage and Valve Cover Bosses were already worked over.... I'm thinking that maybe someone other than the factory did that work before you got them...? Is that possible? (Exchanges?) So do you intend to use your stock Center Bolt covers?

It sounds like there have been some issues with spring breakage when using high lift cams so beware. I ordered the 042750-2 heads with the heavier valve springs. I'm going to use a little lower lift aftermarket roller cam than most guys do, 452/465, with my 1.52 roller tip rockers that equates to a 458/471 lift.

Your point about the cheap valve seals is well taken. It sounds like a good idea to change them sooner rather than later. My car also blows a puff of smoke at start up every once in a while. If I add oil through the filler port in the valve cover it puffs a big one. At 145K mi. I suppose that's normal for these engines.

Some of the posts that I've read are making me think that these heads need to have some exhaust port work too, "Pocket porting" and a gasket match. I may buy some tools and do some gasket matching. I'm not sure if I'll try to work around the valve seats or not, I don't want to have the seats ground...

Tony89

Actually, it appears that (my message ran long and I didn't want to bore anyone) their product literature is behind their actual production. It looks as if that EGR passage is cast in, not punched out, but I'm glad you mentioned that. I had not even considered that possibility. The machine work on the perimeter bolt valve cover bosses is clean and tidy. It just seems that they updated their production policies without updating their printed information, or their website. I guess there are enough decent centerbolt heads out there, not to mention cars that can use them, that these items are finally being taken seriously.

Your point about the springs is also well made. I'm going to change my cam (I found out recently that I have the "peanut cam" yikes) to the crane 104221 (204/214 and .4xx and .452). The interesting thing here is that if you read the spec's on Crane's recommended valve spring #99848, they read almost exactly as do the spec's for the 042750-1 springs. When I called Crane, the tech said I could use the springs I got with the heads and my stock roller lifters. For me, 130lbs. of seat pressure just seemed like too much for the cam (stock or Crane) but for cams beyond that, like yours, an investigation is definitely in order.

Tony89

Mnorton: I apologize for not answering your actual question. As always, I just got carried away. I have a set of those really nice Moroso centerbolt valve covers. They're machined for crane roller rockers, which I also bought. I really hope to *** that they aren't "exchanges." You never know what the heck may have happened to them before you got them. Although, I vaguely remember speaking to someone from World Castings over the phone after I bought them and checked them out. I think he said they had started doing that "in house." Honestly though, it has been quite some time since I bought them.

mnorton

Tony89,
Thanks for your input. I understand what you've said about World changing their product and not updating the documentation.... I tried to get the heads with the 125# springs
(-2) but was unable to get them as they have now been discontinued. It looks like I'll go forward with ordering the (-1) heads and just live with a little less spring than I had wanted, (or replace them...). I had thought about just getting the bare heads, but that gets pretty expensive once you buy all the parts separate...

Your cam choice (the 2030) will work fine, but I feel that 116 deg. LSA is a bit too much for a 5-Speed. If you haven't purchased the cam yet you should really consider getting the (2031) P/N 104225. It has very similar lift/duration numbers, 112 LSA, and would give you a little better power. I think you'd be happier with it.

Tony89

Mnorton: Thank you for continuing to share your thoughts. If I had known how vibrant the discussion was on this site, I would've joined months/years ago. I however have made a mistake. You see, I joined in such a hurry that I didn't give any details about my car. I have an '89 IROC convertible with an automatic. I've put a lot of money into it, with mixed results. One of the most expensive things I bought was Vortech's supercharger. Long story short, blowers like lots of lobe separation (114+ degrees) The stock "peanut" cam has very little lift and duration (bad for normally aspirated applications) and 109 degrees of lobe separation (bad for blowers and nitrous) You basically blow all your boost out your exhaust pipe when you have the kind of overlap that this cam has. I was actually going to use a lower grind from the one I'm choosing, but none of them had over 112 degrees of lobe separation, and the stock 5-speed/350 cam for 90-92 was 207/213 with 117 degrees LS. These factors all have influenced my choice. But, I will check out that cam you mentioned. There may be a 350-383 in this car's future, and a more aggressive grind will be a must. For now, though, I'm going to enhance the 305 as much as possible. One last note. I have Vortech's literature dating back to before I actually bought their unit (1995). The numbers they quote as "stock" for the 305 are always the numbers quoted for the car with the manual transmission. This would partially explain why my results weren't quite what I'd hoped for (5-speed=bigger cam). I hope that changes with my new stuff. We'll see.

mnorton

Hmmm, a blower, I see.... That changes things.

Do you know who Willie is, have you looked into his posts?

Tony89

Mnorton: Is he the guy with the white 305 with the AFR heads and the ATI Procharger? I saw the guy's site. This is one fantastic setup.

mnorton

Willie is this site's moderator in the convertible forum.

I've not looked at his car for quite some time, but the last time I read about it he was running a Paxton supercharger. Yes it is a white z28. He is quite a z28 expert to say the least....

Willie has been very motivated to squeeze big HP out of a 305. He takes it to the track and tests his mods. This guy is very bright, and is meticulous when it comes to his cars....

You should do a search on his posts (search on "Willie") and look through them. I think you'd probably learn a thing or three....