[maxxman04]

so...i'm 100% done with vortec heads. been thru two sets in a week. both cracked. it's cost me almost $800. we won't go into the dimensions of p'd off i'm in. second set was supposedly just rebuilt. surface was clean, had receipt. straight edge show true. but as a precaution, i always have heads checked out. sure enough, cracked. after adding this all up, with a new set of improved vortecs, plus the correct manifold, it'll cost me close to another $800. uh. NO!!!!

so, there is a possibility of light at the end of tunnel. shop that i use for all my work, very reputable, is offering to help. he has a set of fresh 810 heads. now, my understanding is these are 65cc, 1.94 tbi swirl heads off 350 truck motors. in talking with him tho, he thinks for what i am after, they are a great head, with good economy, low to mid performance. which is where i'm headed. motor is going into a 2.73 rear gear camaro. being built for cruising, highway driving, with an OCCASSIONAL trip thru the traps.

here's the deal. he is offering both heads, with 3 angle, just enough mill to clean up, and a matching, correct rpm performer intake, all for $125. i've heard bad about these heads, but have read SOME good. for what i am after, is this a good deal, or should i pass?

350 30 over flat top, 262 cam, 218/224 @ .050, 462/469 lift, 110lsa, professional built quadrajet (ruggles) 1 5/8 headers hei

[OneMoreTime]

That could be a good deal as those heads can give you miles of smiles with no issues. the main reason for the big port heads is when a person needs to move a lot of air to support high RPM operation such as a serious race motor..I would however run a check on compression ratio to make sure your motor will run just fine on regular pump gas..

Sam

[maxxman04]

thanks Sam. according to CR calculators, with a 4.166 bore, .039 gasket it would put me about 9.9:1, with a quench of .051. the quench might be a bit high, not sure, still researching. as stated tho, this motor isn't being built for all out race. 99% of it's time will be daily driven, weekend cruisin, with the occassional run down the track just for fun. i know the 810's are no where near as good as the vortecs, but after my latest experience....well, just no interest in the vortecs anymore. from what i've read, the 810's do ok up to about 4000 rpm. higher than i intend.

[454C10]

what is wrong with your old heads again? were they 882's 76cc?

Swirl port heads are terrible. I would keep what you have.

I think 9.9:1 cr is too high for a little cam like that. You will need to reduce timing to prevent detonation, plus there is a big load on the engine (2.73 gears and OD trans).

[maxxman04]

bought two different sets of heads in the last week, both vortecs. first set was not rebuilt, second set supposedly was. by looks, they looked rebuilt, not just cleaned up to sell. both sets were cracked. which has left a sour taste for vortecs. the shop i had check them has a set of 810's rebuilt, with matching intake for a steal. yes, i understand the swirl ports are not desirable "racing" heads, but this is not a racing motor. reliability, economy is the goal. after spending the amount of money i have on "better" heads, the budget for heads is tapped. the rear will be swapped to 3.23's in the future. but as stated, this is a DD/cruiser, not a racer. just trying to get input based on this. thanks.

[gearheadslife]

anyone that buys used iron heads without a reciept for a mag test..
is pissing money away.. and the o/p being mad, tho. understandable..
isn't the vortec heads fault.. it's whom he see's when he looks in mirror..
sorry you're having bad luck..

hard lesson to learn.. twice..
any heads I look at I ask the seller to get them mag'd and add the cost to the sale price. if they won't I don't bother talking anymore

[maxxman04]

second set did have receipt. and mag residue. not sure what shop did it, rebuild done in december. i agree. i never buy used heads without having them magged. like you, i make a deal with seller as far as cost. but, i took a chance on the first set, without it being done first. got alot of valves/springs and stuff now. lol.

[Mr. P-Body]

For the most part, Vortecs are pretty good heads. Cracked ones aren't all that common. How did you find the cracks if they passed "mag"? We usually pressure-test assembled "used" heads. Unless the crack HAPPENS to be on the flat surface of the deck (rare for ANY kind of head), it's the most effective method.

I don't recognize the "810" casting number (191s, 193s I know about, 081 is a 305 version, so maybe that's what it is. The small chamber would indicate that). I do know, the "winged" intake runners offer excellent low-speed and mid-range flow. As another said, they're terrible for any serious volume. The small chamber is a problem for pump gas. Combined with the XE cam, it could send cylinder pressure too high and induce detonation.

That particular cam is not a "high speed" cam (5,200 or so and it's "all done"), so RPM is not the best choice. Performer would be much better. Coupled with the limited flow capacity and "swirl effect", this would be a very "torquey" engine with lots of low-end and mid-range, ideal for the 2.73 gears. Be certain Cliff knows it's NOT a "rev engine" when he does your carb. I don't know anyone that can dial a Q-Jet in for a given application any better than Cliff.

Jim

[maxxman04]

the 810's, by my understanding, are early 90's 350 truck heads. 65cc, 1.94/1.5 valves.

i'm not sure either about the cracks. both sets had cracks in one of the water jackets. the shop i use is a very trusted and reputable shop, building reliable, winning motors for pullers and drag racers. i personally watched the mag test he did, and sure enough. now, the cracks were not hideous, but they were there. so maybe the other shop didn't mag heads right. dunno.

as for intake, i have read the same as you say. use the performer. and this motor won't see high rpms. hence the thought of the 810 heads. decent efficiency, good low and mid range torque/power. and for the price....almost can't pass it up.

thanks for your input Jim. greatly appreciated.

[GMC boogie]

810's were used on the HD 350 TBI engines. They have 3/8" diameter valve stems. Not a performance head but, will do for what you want.

Pretty sure a RPM intake is not available for those heads. The two center intake mounting bolts are at a different angle. Maybe he modified the intake to fit.

[maxxman04]

edelbrock does make an intake with the 72 degree center bolts. i've used it before. gonna go with it.

also, doing some math, if i use a 4.166/.039 gasket, puts me in 9.9:1, but puts quench at .051. better to run a thinner gasket and raise CR, or......?

[maxxman04]

ok, if my math is correct, and KB's scr/dcr is correct, then i should be right where i need to be.

first, my cam's intake closing @.050.

duration @ .050 divided by 2, plus lsa, minus 180

(218/2)+110-180=39. per other members posts, add 30 for flat tappet cam to get approximate int. closing point. KB says +15, but it's been said that's too little.

per KB calculator

cylinder cc- 65cc
piston head volume- 5cc
gasket thickness .039
gasket bore 4.125
cylinder bore 4.030
deck clearance .012
stroke 3.48
rod length 5.7
intake closing point 69
abdc @ .050 +15
(+30 sub'd as advised)


Static 9.978

Dynamic 7.708


seems that this is bout perfect for pump gas, economy and such. right?

[GMC boogie]

That cam installed at 106 ICL has an intake closing at 57º ABDC.

Using Pat Kelly's DCR calculator, I get a CR of 9.97 and a DCR of 8.42


You really need a 11-12cc dish piston or a larger chamber head.

[maxxman04]

but according to comp cams and the spec card, that number is at .006 lift, not .050 lift.

[cobalt327]

Unfortunately the following won't help you, but hopefully it will help the next guy:

• Finding good used heads