Lt1 Block Machining Question N Head Work???

[Guest blongzZ916]

Hello All,

Not sure if this would belong in this forum but I got a 95 Lt1 that I am in the process of stroking it to a 383. I got some Trick Flow heads with 62cc chambers.

Question #1:

Block machining - I requested the block to be cleaned and magnaflux for quality, and the block torqued bored to the require piston to bore specs. Anyways, the machinist called me back today and said that they do not use a torque plate and that they have never had any problems with their blocks. He also said that all the machinist he knows doesn't use a torque plate. So, I am just curious how important this is if machinist with 10 - 15yrs experience say it's not necessay? Is it because it's an iron block?

 

Question #2

Head Work - I got the trick flow heads and knowing who I am I took the assembly apart to just see how well these things look. Well, I felt under where the valves seats are at and found some ridges where they had machined. I think even though I don't have much experience in head porting, should I at least try to smooth that part of it out (get rid of any ridges) and port match with my gasket? Not looking for anything great but I think just doing that my gaine a little cfm.

 

Thanks, for any replies......

[BRAAP]

Please don’t take offense, but as a professional engine builder/machinist myself, there is a part of me that feels you may have misunderstood the machinist on some level and misinterpreted what he was saying in regards to the use of a torque plate?! You did make it clear to him that this is a performance engine build up, right? If my gut reaction is wrong and what you stated is indeed what the machinist told you for a performance engine build, my professional opinion is to find another machinist that specializes in performance orientated engine work.

 

There are some instances that might not warrant torque plate honing, such as a bare bones budget overhaul for grannies daily driver that may only see 1000 miles a year and Granny is on fixed income. For a performance application, if the budget can afford it, then yes, using a torque plate does help make the cylinder walls more concentric for better ring seal.

 

As for the head issue, what you are describing is in essence basic “pocket porting” and it will yield some degree of flow improvement. Pocket porting OE SBC heads, the gain is substantial. Pocket porting aftermarket heads, depending on the heads, casting quality, post processing machine work etc, the gain is generally smaller. If you do take the cutter to your heads, remember to keep ALL radiuses as gentle and as large as possible. Sharp corners and sharp transitions should be avoided, i.e. if removing material causes a sharp transition from one plane to another, then don’t carve, just lightly remove the ridges/high points to make the radius as clean and smooth as possible.

 

Good luck,

Paul Ruschman

[jakeshoe]

I will 2nd the info provided by Paul. He is absolutley correct. It sounds as if your machinist may not even have torque plates. If he doesn't have them for a SBC, he doesn't do performance engine work. Find another machinist.

[DavyZ]

I would think that the central valley in general is full of performance engine builders who can do what you want. The nice thing is, you can make a few phone calls. Try picking up a DRIVE! magazine and look for ads for engine builders. There are so many local advertisers in there for just about everything, that it is great, even better than the Internet in some cases. Not everyone has or needs a website.

 

Davy

[Guest blongzZ916]

Thanks for the information, I have called and found several places that utilizes torque plates.