Question on head gasket and oil additive
 

I was hoping someone could tell me what the bore size is on a GM part# 3995633...it is for a 283/307 engine. If I had to guess it would maybe be 4.100. And, I was curious on what the equivalent Fel-Pro gasket might be (maybe a 7733SH1).

One other question too...what is a good oil additive to run on a low volume oil pump setup. I haven't quite completed my engine yet, but I want to get a good guess on what weight oil and potential oil additive to run.

thanks,

Re: Question on head gasket and oil additive
 

I have been using Amsoil Synthetics for years and it works exactly as they say. My next manufacturer would be Royal Purple. Call their tech lines and they can recommend something. Amsoil has a 0W30 that is absolute killer. Oil treatment wise, Pro-Blend makes a Racing Concentrate that will protect your motor and free up some power. I've run this product in everything and once again, a product that does exactly what it says it does. Be sure to seat the rings before you use it though.

Re: Question on head gasket and oil additive
 

thanks, I am going to try some of that oil and oil additive on the dyno...after I break it in good. I hope to see some improvements, but at the same time I want my engine to last. Where can I purchase Amsoil?

Re: Question on head gasket and oil additive
 

Get online and get their main number out of Superior, WI and purchase a dealership. That way you can get the oil at dealer cost and save on paying retail for it. www.amsoilsynthetics.com

Re: Question on head gasket and oil additive
 

should I mix the pro blend with the amsoil?

thanks for the info...I got set up with Amsoil synthetics and ordered some.

Re: Question on head gasket and oil additive
 

Absolutely. To me it's the ultimate in protection. I'll give you an example; my wife's daily driver we bought new and after I put some miles on it (about 1500) I switched over to Amsoil and Problended it with the Racing Concentrate. Now it has over 122k on it, oil consumption is about the same and I only have changed the oil and filter 8 times. Saved lots of money these last 5 years with this combo. ProBlend is located in Winston-Salem, NC and get their direct line at the factory.

Re: Question on head gasket and oil additive
 

The bore size on a new # 3995633 is 3.980. This gasket was used for the 307 motor,is steel shim & has a coating on it.
As far as I know G.M. has discontinued this gasket.
Not sure of the Fel Pro cross over #.

There are a couple of smaller bore gaskets G.M. # 14085906@ 3.875 & # 462690@ 3.875. They are both steel shim & have no coating on them.Also no longer available.


Just curious,what is the exact bore size of your motor?

Allan

Re: Question on head gasket and oil additive
 

I also rely on Amsoil products. They recently came out with a line of race-specific oils also.
http://www.amsoil.com/news/2008_Dominator.pdf

However, Amsoil does not recommend mixing any additives with their products citing that their oils already have a pretty complete anti-wear and anti-friction package included and mixing chemicals could compromise them. I tried a variety of stuff years ago before switching to Amsoil and didn't see any long-term benefits in any. I've always used straight Amsoil products and have seen the benefits on the street and the track.

For more info on the oil and dealer/wholesale pricing, you can contact the person I deal with - Dan Watson.
www.thelubepage.com

Re: Question on head gasket and oil additive
 

I am building a 307 .060 over. 3.935 is my bore size, so that GM #3995633 would be perfect, but if it is not avaliable then I will have to find a gasket with similar specs.

In case anyone is curious, I found the Fel-pro replacement head gasket for the 307 GM#3995633. It is a Fel-Pro #7733SH1 and it is the same except the bore size is 4.100.

Myron, do you run the 0W-30? and how does the Amsoil racing oil compare...I didn't see a 0W-30 racing oil?

Re: Question on head gasket and oil additive
 

Cometic will make gaskets for you, to your specifications. They are certainly pricey, as much as $200 for a set. But if you are careful, you can reuse them 2-3 times, or more. If you give them a bore size and a thickness, they'll be close to dead on. Mine have not varied more than 0.005" on bore size (always big, not small) and no more than 0.002" on thickness (always thick, not thin).

Re: Question on head gasket and oil additive
 

The motor oil is now named Amsoil Signature Series 0W30. The also have a 0W20.

Re: Question on head gasket and oil additive
 

Castrol also frowns on using any additives with their oil. As the rep stated " why undo something that our chemists have engineered into our oil ?"

Re: Question on head gasket and oil additive
 

Those are not the same oils. The Dominator Series is new as of last year and are fortiufied more for the racing environment. The Signature Series 0W-30 may have gotten reformulated a year or two ago. I'm only speculating, but it may have to do with newer model emission regulations and compatibility, similar to a new diesel formulation for 2007 & newer diesel trucks. I believe the zinc content has something to do with it. The race oils, older diesel, including the HDD 5w-30, and some of the others, still have a large amount of zinc and similar additives. It's all good stuff nonetheless.

Re: Question on head gasket and oil additive
 

I would have to agree with Alan on the head gaskets. I have used Cometics on our 283 and 327s and reuse them 3 times, then I take them off and save them. I probably could use them again. They get pretty reasonable when you get to use them more than once. You tell them the bore size and thickness and they take care of it.

Re: Question on head gasket and oil additive
 

The product I was referring to was either the Series 2000 (or might be 3000) and they are a different product line from the Dominator series; it looks like they renamed it but I have to check with tech to verify it. And you know that the chemistry will work either way.

Re: Question on head gasket and oil additive
 

I have head gaskets you are looking for if you are interested. email theshop@texomaonline.com

Re: Question on head gasket and oil additive
 

I appreciate it, but once I found out that the 7733SH1 was the replacement...I got it and I believe it is what I will use at this point. I am hoping to have her running in about a week...so as my normal price and time estimates go it will probably be about 2 weeks and twice the costs that I had orignially planned for.

Re: Question on head gasket and oil additive
 

((I am building a 307...just trying to go a couple tenths under...hopefully. This engine will not turn over 6000rpm to speak of, the piston rock is approximately.005 and on the high end it sits about .002 in the hole. ))
7733SH1 aprox .015, with your .002 makes .017...gonna hit. let me know what you see when it comes appart...

Re: Question on head gasket and oil additive
 

Well, I have been scared away from making the clearance that tight...I just am trying to get as much out of everything as possible and taking thousandths away from the piston to head clearance will definitely increase compression which is definitely a gain of some sort. I decided to go with a .028 thick gasket which will yield about .030 clearance.

Re: Question on head gasket and oil additive
 

Mobil/ Mobil 1 makes the base oils for all synthetic oils. I used to sell race oils. When you read the specs for synthetic motor oil and compare them all, this is what you will find: everyone has a hard one for additives that makes their oil different. When you look very close, many are only slightly different competitors to Mobil 1. They really only offer slight advantages. Most are only noticeable in lab reports. SAVE YOUR MONEY. Brad penn 0-30,10-30 semi synthetic and Valvolone VR1 are the best for the $ spent. Amsoil does offer a oil analisys that will answer any questions about the oil you are using. They contract with a private company. You can deal with this company direct. OH BY THE WAY, ask 50 racers about oil and you'll get 53 answers.