Jump to content

BB 454 HEADs


MAQ's72

Recommended Posts

So that explains the good price @ $400 rebuilt, they are like truck heads.

 

Please enlighten me on 049 or 781's   what years or what should I look for to get those heads? and what's the best block year number to go for?

I found these Merlin heads not too far also, more than double the $ but I can swing it if they are worth it?

 

https://tampa.craigslist.org/psc/pts/5979859225.html

Link to comment
Share on other sites

Horsepower requires some investment.

 

You need to start by knowing the CC's of your pistons. Then you need to match head combustion chamber CC's to get your desired compression ratio. This determines pump gas (max 10 to 1 ratio) or race gas (12+ to 1 ratio).

 

Then what RPM range do you want to operate in? Low RPM means smaller ports to keep the flow velocity up (peanut heads are too small for any power in any range). High RPM means bigger ports to allow flow. Rear end ratio comes into play here.

 

Intake manifold, low or high rise? Dual plane or single plane?

 

Then you need a camshaft to match everything you've already determined.

 

I would suggest you contact Edelbrock with all your car details and what you want to do with it. Edelbrock is the foundry for almost all Chevy heads, even supplying GM. They'll recommend a head/intake/cam package that will work well together. You'll need to have piston CC, car weight, rear gear ratio and exhaust system details in hand for them to know what to recommend.

 

Your package will more than likely be aluminum heads. Use Cometic MLS head gaskets and ARP studs. This will help seal the heads on those four cylinders "missing" the top head bolts.

  • Like 2
Link to comment
Share on other sites

Regarding peanut 236 casting heads. Has anybody here checked the Chevelle site or heard anything about member there named Vortecpro? I am in tear down phase of an 82 14015445 stamped block with the 236 peanut heads.Vortecpro has a very long post about his build to strip test of a 467ci, mild cam, low 9.2 compression, peanut head engine that doesn't "sound" like much. Link to post is below, long read but tons of info. Guy doesn't keep any secrets. Also search YouTube for Vortec pro peanut and watch some of the testing in full body Chevelle and dyno pulls. I will post screen shot below from one pull.

 

http://www.chevelles.com/forums#/topics/794225?page=1&_k=dcuplw

 

post-5469-0-59469600-1488657319_thumb.jpg

  • Like 1
Link to comment
Share on other sites

Vortecpro does some amazing things. But those 236 castings are not left as cast. I have a set of stock 236's on the 454 in my 1977 k10. For what the are the are perfect for my truck. But if you are starting with a performance build the best factory as cast heads are the 781 or 049. Like I have on my 1970 Monte. I did have the machine install 2.19 intake valves and 1.88 exhaust valves. The short test drive I was able to do before I put it up for the winter I was able to feel a difference via the "butt dyno" over the stock valve sizes. But I intend to test it fully at the strip later this year. FWIW David

Link to comment
Share on other sites

I agree with your statement of "not as cast". But wouldnt that also include altered valve sizes? Anyway, Vortecpro in just the third quote from his post he describes what he does to the heads.

 

"I fully port the intake and exhaust, and chamber, although you don't want to get them to thin. 1.88/2.190 valves."

 

So, good porting and little bigger valves. Then he actually posts flow numbers on heads before and after porting. Post 33

 

"Flow test on the un ported 236 heads with a 2.190 intake valve installed. Its interesting to compare these flow numbers with other heads of the muscle car era.

 

Bad Port

 

.200 143

.300 205

.400 228

.500 238

.550 Done

 

Good Port

 

.200 144

.300 206

.400 238

.500 245

.550 Done

 

2.190 intake valve, no back cut, 4.310 bore, tested @ 28 inches."

 

Two post later somebody else posted flow for stock 781 heads.

 

"781's? you can see some stock flow specs here: http://www.users.interport.net/s/r/srweiss/tablehdc.htm

 

intake with stock 2.06 valve

.100 100

.200 142

.300 190

.400 217

.500 238

.600 270"

 

If you are looking for a good solid, daily drivable engine, that will make people do a double take when you tell them what you have and how little you had to pay for it, go with the 236. Port them yourself if you feel you can. Or have a good shop do the work. I will be attempting the porting myself the help of a great book that was recommended by some locals, it's David Vizards How to Port and Flow Test Cylinder Heads. I will be building the budget flow bench as outlined in the book. And testing my porting ability frequently as I get into my heads. Take another look at the numbers in screenshot of dyno pull, and ask your self if that isn't enough for a daily runner budget engine that is happy with pump gas.

  • Like 1
Link to comment
Share on other sites

Have to chime in here. I have an engine built by Vortecpro. (Mark Jones).

I was surprised to find peanut port heads on this engine. On top, he has an Edelbrock RPM intake. It's interesting to see the tiny ports in the head, and the large runner size of the intake. It has an abrupt change there...It's like the air going down the intake, then meeting with a wall that has a window in it. It just seems to go against the smooth sides theory of keeping airflow undisturbed.

 

The good news is that it seems to work ok. I asked him to build me a strong street motor, and this is the combo he sent. He sent a dyno sheet with good numbers (502 hp, 600 tq) but this is not an engine that is good at the dragstrip. It feels very powerful on the street, with instant throttle response and very good driving manners. Sadly, all the excitement fades away as the engine revs above 4500 or so. (my dyno results showed peak numbers happening at about 4500). And to say Vortecpro doesn't keep any secrets? well, I can't agree with that. Getting any details on what my motor had inside was like pulling teeth. I didn't even know it had peanut port heads until I had to replace an intake gasket.

 

The end result? This engine feels very strong in daily driving situations. It has no trouble spinning the tires, and drives well at freeway speeds. It makes the Monte feel like it has shed a lot of weight. I was happy with the engine until I tried it at the track, and was surprised that it was slower than the old engine that it replaced. (the old engine had cast iron Merlin heads, and higher compression). This engine would be ideal in a boat, but can't pull strongly all the way down a dragstrip. Merlin heads have their own quirks, so those are still on my shelf waiting for "someday".

  • Like 1
Link to comment
Share on other sites

Migster69 that is some good data that you posted. I also agree that the larger valves are a major mod. I probably shouldn't have mentioned them as it does muddy the waters. To the OP if you can find a set of 781 or 049 heads with stock valves in good shape do not be afraid of running them as is. There are guys on TEAMCHEVELLE running 11's with these. In my case the heads needed to be rebuilt and the machine shop was able to do the upgrade for a few dollars more. It is also a way to save heads that the valve seats have worn out. I hope that my advise helped more than confused things. David

Link to comment
Share on other sites

The factory heads on mine had induction-hardened valve seats for use with unleaded fuels. My machine shop said I would loose the hardened seats if I wanted to install a larger valve. I could have hardened seat inserts put in, but it's pricey... it was cheaper to buy a new set of Merlins that were already set up.

For me, the major problem with the Merlins was the raised exhaust ports. It's a big selling feature and improves flow, but it causes  very tight clearance for the spark plugs. I had big issue with the stock cast-iron exhaust manifolds, as there was no air gap between spark plug boots and the manifold. Even the skinniest boot would press against the manifold. The boots would burn through in no time. I ended up going to a header, but those are bent for un-raised ports also, and came with a new set of issues.

  • Like 1
Link to comment
Share on other sites

A Lot of good information guys thanks But to be honest with you puts a lot of doubt in my mind as to if I can do this as there are a lot of variables..... Been looking for a good machine shop in the area but have not had good luck as most do just rebuilt to fact. specs..

 

I have a good motor in her now but not what I want, as a buick 455 is not exactly what a Monte came with so thought I will slowly build a 454 to swap out. I don't want a drag car but a strong muscle/street car that can hold it's own. 10/1 compression no more than that with a mild cam and some good heads, dual plane edelbrock probably and headers... I'm a fair mechanic but not by trade, did a motor swap about 30 years ago..wow... (time flies)  helped a buddy hone the block as we did in the old days with a drill and honing stones... installed new bearings and rings etc. on his 350 before we put it back in... he had a 307 in an Impala. As most of us on here I just get satisfaction of doing it myself.

 

So your help and advice is appreciated... !!

  • Like 1
Link to comment
Share on other sites

With what your goals are, the stock valve sizes will be fine. But if you find a set with the larger ones installed don't be afraid to pick them up if they are a decent price. Your desire for 10 to 1 compression is a good one. Big blocks love compression. Just make sure that you don't go too mild with the cam or you will be prone to detonation, I have a Lunati 10110703 in mine and it works very well. If you can get an Edelbrock RPM or similar from another manufacturer, 750 CFM carb, 1 7/8 headers ( I have Heddman can't think of part # ) and a electronic ignition with a good curve. You will make your horsepower goals with no problem. You are right about there being almost too much information. You are in a good position with a running vehicle so take your time and beware of the "more is better" trap during your search. Particularly the stroker crank lol. I struggle with that one myself. David

Link to comment
Share on other sites

I agree with the above. The problem is GETTING that compression. The good-breathing heads are open chamber and finding a piston to fill it is a challenge. It seems they have lots of choices for 8:1 compression, and then it jumps to 12:1.

 

Planning an engine build can be an exhausting process. You find the perfect part you need, and then you have to change a bunch of stuff to make it work.... But it doesn't have to be that hard. Save your money for the parts that make the most improvement. The cheapest way to get more horsepower is to put in a larger engine. That being said, the big improvements will come with a fresh set of stock oval port heads, and a cam. Don't forget to get the matching lifters and springs. If you're in there, figure on replacing the timing chain as well. A professionally recurved distributor makes a "seat of the pants" difference. Everything else for me was money spent, but little difference felt. Intake, carb, headers, all add little and can be added later if you want.

I ran a stock 396 with nothing but a cam upgrade, and it was amazing. Very powerful, reliable, and cheap. That engine still had the iron intake, exhaust, and Q-jet carb and was good for low 13's.

  • Like 1
Link to comment
Share on other sites

I like that thinking on both of the last post wallaby & David... not go too crazy. I want to run on pump/high grade gas, if I can achieve the 425/450 HP with the suggestions you guys bring to the table with the right gearing she should be plenty fast. Not sure on the compression deal for the BB as I think 12:1 would not run well on pump gas and I might not have enough vacuum for the power brakes with the cam you would have to run with that comp. I would think.

 

What do you all think of this deals locally here on CL, $500 for block and heads (bare) also is a 4 bolt main that necessary with under 500 HP?  I have seen plenty but are newer truck motors I believe.

 

https://tampa.craigslist.org/pnl/pts/6013954183.html

 

And also this nice set of oval port heads..

 

https://fortmyers.craigslist.org/lee/pts/6023220586.html

Link to comment
Share on other sites

A 4 bolt is not nessisary, keep the compression under 10:1 esp with iron heads, a speed pro L2399F piston has a 13.8cc dome, I'm running these with 781's shaved down to 108cc and giving almost perfect 10:1, I had my block decked .010 too

  • Like 1
Link to comment
Share on other sites

I agree with Bones. If the block you listed has the 781 or 049 castings jump on it. If they don't......it's up to you. But don't stress about using a two bolt or even factory fasteners at your horsepower goals. Those heads are the big block version of the vortec. You could make them work but they will be best on a low RPM engine. The plus is the small 100cc heart shaped combustion chamber. Disadvantage is a vane in the port that is to promote swirl, works low RPM but will ultimately impede flow. Also if you ever decide to install larger valves the chamber design shrouds the valves losing power. These heads are great in a truck application. David  

Link to comment
Share on other sites

Bones had mention those head cast # to me before 781/049, that's what I'm going to look for. The block and heads that were for sale locally are gone, called the guy today to see what the cast # on the heads where. Good big blocks are getting harder to find that are not vortech blocks I see. Dam, 600 HP I wish, nice to know they are that stought from the factory with just some tweaks... 

  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...