Hi everybody, this is my first post, but I've been reading for quite a while.
I'm a recent owner of an 81 Vette (what else!!!), newbe in the the V8 world as my previous experiences were with DOHC cars (I've been owning and tuning my mazda Mx-5 for 5 years now).
My major problem is that I live in Italy (sorry for my english) and can't find much about Vette and in general V8 cars as even the dealers don't cope with such old cars......
Anyway, as far I have noticed, my car had some upgrades done, and I'm trying to get the best-bang-for-bucks (did I get it correct?) to improve the engine and suspensions, considering also that money wouldn't be a huge problem if I hadn't to cope with international shippings and taxes...
At this point my car has long tube headers, no cats, duals and free flow mufflers together with Performer intake and 600 carb with Accel distributer (dunno if it's only the cover or the all of it).
As far as I can see, there's non more smog stuff.
To try not to seem stupid, I also bought a book about rebuilding a short-block, so please be patient with my knowledges after be patient to my language...
Back to us, will be easier to work on the exhisting heads (shaving to raise the CR and port jobs) or try a swap? What heads can I swap without too many efforts? About cams?

Thank you for your BIG help!

 

Welcome to the Forum first off. It sounds like the car has been modified so there are all kinds of options available to you. As far as heads there are a lot of choices. The AFR street 180 is one of the best for a street car and one of the most expensive. Edlebrock has heads, Brodix, Dart, several others. For myself I would stay away from the chinese aluminum units but a lot of guys have had good luck with them.
There are many many possible cams to use. That should take some thought and be matched up to head selection, desired performance charictistics etc..
Go to www.summitt.com and to www.jegs.com and start looking there. There will be some other guys pipe in with suggestions also

 

First, thanks for your reply.
My question was to undestand if there's enought material to work on the stock heads because, as I explained, shipping to Italy those heavy pieces is quite expensive and takes even a couple of months (shame on you postmen!) to be delivered...
I read on the forum about the L98 or ZZ4 heads which will work fine for my case (the L81 CR is really low, so using heads with a smaller combustion chamber will raise it and on those should be of 58cc), but assuming that i might find them on ebay, do I have to make some mods to use them on my block?
Going back to work on the stock ones, do I have to change rockers and pushrods if I shave them?

 

Also, would I get any improvement taking the A/C belt off?

 

[QUOTE=VenomThyBloody;1565316360]
At this point my car has long tube headers, no cats, duals and free flow mufflers together with Performer intake and 600 carb with Accel distributer (dunno if it's only the cover or the all of it).
QUOTE]


Thats a damn good start. The 81 heads were "lightened" by so much iron that most shops won't work them other than a valve-job. They really arent much to start with flow-wise. As previous posted, the AFR180's are awesome but expensive (i choose that route) but there are several other good head choices. World S/R Torquers and Vortecs (which you'd need a different intake) were my choices if i stayed with iron vs alum. It all depends on how much hp you eventually want and how much you can spend to get there.
Here's a thought, alum heads might come out even $ when you consider the shipping cost diff to Italy

 

on the Iron vs Aluminum thing. The 81 heads are not mush as posted. If your looking to make some relatively inexpensive HP, the 81 has dished pistons. You could go with flat tops and improve the compression, although concidering that means pulling the motor its a lot of work.
Also removing the AC belt isn't going to do much for you, if it works and you use it, leave it there.
There is annother member over there in Italy...trying to remember his screen name...
,PANIC....look him up, he may be able to help you with some sourcing over there

 

Good advices... but what if I just want to shave them to raise the CR?
Without considering shipping fees (imagine those heavy heards in a transoceanic trip... ), the taxes at the border are around 20% including shipping fees, and that's a lot, let's say a 30% on the overall price...
I tought about pistons, but again a complete rebuild will lead me to the same story I began with the mazda (1928cc engine with 12,2:1 CR), and I want something that could be also reliable
Has anybody shaved the heads before?

 

it called milling the heads. i dont know if you would gain all that much for the cost. remember, milling the heads down and running a thin gasket puts the valves that much closer to the piston @ TDC. I'm guessing you MIGHT get 10-20 more hp by this, but you PROBABLY are trading reliability for it. You just as easily ditch the fan and go electric fans for the same OR run underdrive pulleys.

 

You will probably find that the original heads have cracks after you take them off. They are very thin and almost always show cracks around the valves. I replaced mine with Dart Iron Eagle 180's and have been happy. God bless, Sensei

 

20hp just by using an electric fan? Is the standard fan just belt driven or does it have some sort of clutch (mine stays always on)?
Underdrive pulleys, more infos?

 

On an 81? What CR you achived? Price?

 

A cam is an easy & cheap option to swap in for HP improvements. You can swap in a hot cam with the engine still in the car.
"Shaving" the head will increase the compression ratio, but you usually " deck" the block, not head.
I'd suggest a new cam shaft, aluminum Edelbrock 2101 intake (it fits under a stock hood) and aluminum heads (Edelbrock are cost effective).
If the engine still has the computer, then you may be able to research finding a performance chip/software to improve performance.

Chow!

 

I read that the cam should be changed only accordingly to new heads. Would you suggest a combination cam/heads for my set up (the first post expains it all)? My goal is to reach around 300hp...
I already have an Edelbrock Performer intake, and the car now is fully carb.

 

Dart Iron Eagle at Summit
http://store.summitracing.com/partde...5&autoview=sku

 

I bought my Dart heads on Ebay for about $800, delivered (US) and ready to bolt on (I polished the chambers, that's all). With these heads (72 cc chambers) and flat top pistons, I think my CR is around 9:1. I also have headers and duals, and a Comp XE262H cam.

With this combo, I'm sure my HP is a bit beyond your goal of 300.

If I had it all to do over again, I would have ported the heads and gone with a roller cam conversion, but overall, my car runs very well and is respectably fast. God bless, Sensei

 

I don't want to change pistons...
What year is your Vette? You would only have done a port job and a different cam? What do you mean by "roller cam", mechanic lifters?

 

What cam do you suggest with those heads? Do I need to change anything else?

 

I went with the DART Iron Eagle 180cc heads with 72cc combustion chambers as I wasn't looking for a big jump in compression (they offer 65cc chambers). Great as-cast technology, assembled with quality name-brand parts and heavy castings. I had light casting '624' cylinder heads on my '80 (OEM). Ditched them when I rebuilt in 1999.

 

I think the Comp 262H will work with those heads.

 

You can read my engine build at;
http://www.cardomain.com/ride/2658106/4

Remember that the latter C3 Vettes were porkers at 1530 kilos.
Put as much aluminum on them as you can to reduce weight and that will help with performance.

I went with 62cc heads and dished pistons for 9.5:1 compression ratio. I live above 2000m in Colorado, so you don't get a lot of HP due to the altitude.

Chow