big block heads on small block
#3
They will physically fit, but it's not worth it unless you are doing major work to it. It would require new pistons just to get the compression back up to where it was and either a performer RPM or Victor intake due to the taller ports.
Like ^ said stick with the SBO heads. Have them ported and larger valves installed if they are small valve versions (most are).
Like ^ said stick with the SBO heads. Have them ported and larger valves installed if they are small valve versions (most are).
#4
It can be (and has been) done in the past. As noted, the 80cc BBO chambers will drop compression, requiring new pistons to correct. Ports are larger, but this is only a benefit if you plan to run at high RPMs. Intake must be port matched to the heads. Only a few intakes have enough meat to do this. Performer RPM is one that will work.
Note that you can easily put the BBO valves in SBO heads.
Note that you can easily put the BBO valves in SBO heads.
#5
My dad has been running E heads on a 350 since 1978 and they work great. now granted there are somethings to you have to do to make that combo successful.
the motor has Jahn's semi-dome 12:1 pistons and has has the heads milled. Now he has to run 100+ octane to drive it since the heads were milled .01" he use to run Holley street dominator intake and had it port matched with a 780 holley and it ran good with an original W-31 (casting number 194) not an aftermarket W-31 cam. Now it has a Mondello cam .544 lift and then he went with a 950cfm holley 3 barrel and full polish and port job on the heads and lots of other goodies and it ran great. then now it has the offy low-rise dual quads with 2 500cfm elderbrocks.
Moral is the motor is balanced for 10grand and the cam setup and everything else is midrange to high range power. This is the power band he wanted and after a lot of researching and figuring out the best combos the big block heads work great with his combination.
So what I am trying to say is if you want your SBO to be a low to mid range power motor then NO to big block heads. But if you want a mid to high range motor and utilize the high revs of the 350 then BBo heads can be benefitial
the motor has Jahn's semi-dome 12:1 pistons and has has the heads milled. Now he has to run 100+ octane to drive it since the heads were milled .01" he use to run Holley street dominator intake and had it port matched with a 780 holley and it ran good with an original W-31 (casting number 194) not an aftermarket W-31 cam. Now it has a Mondello cam .544 lift and then he went with a 950cfm holley 3 barrel and full polish and port job on the heads and lots of other goodies and it ran great. then now it has the offy low-rise dual quads with 2 500cfm elderbrocks.
Moral is the motor is balanced for 10grand and the cam setup and everything else is midrange to high range power. This is the power band he wanted and after a lot of researching and figuring out the best combos the big block heads work great with his combination.
So what I am trying to say is if you want your SBO to be a low to mid range power motor then NO to big block heads. But if you want a mid to high range motor and utilize the high revs of the 350 then BBo heads can be benefitial
#9
My dad has been running E heads on a 350 since 1978 and they work great. now granted there are somethings to you have to do to make that combo successful.
the motor has Jahn's semi-dome 12:1 pistons and has has the heads milled. Now he has to run 100+ octane to drive it since the heads were milled .01" he use to run Holley street dominator intake and had it port matched with a 780 holley and it ran good with an original W-31 (casting number 194) not an aftermarket W-31 cam. Now it has a Mondello cam .544 lift and then he went with a 950cfm holley 3 barrel and full polish and port job on the heads and lots of other goodies and it ran great. then now it has the offy low-rise dual quads with 2 500cfm elderbrocks.
Moral is the motor is balanced for 10grand and the cam setup and everything else is midrange to high range power. This is the power band he wanted and after a lot of researching and figuring out the best combos the big block heads work great with his combination.
So what I am trying to say is if you want your SBO to be a low to mid range power motor then NO to big block heads. But if you want a mid to high range motor and utilize the high revs of the 350 then BBo heads can be benefitial
the motor has Jahn's semi-dome 12:1 pistons and has has the heads milled. Now he has to run 100+ octane to drive it since the heads were milled .01" he use to run Holley street dominator intake and had it port matched with a 780 holley and it ran good with an original W-31 (casting number 194) not an aftermarket W-31 cam. Now it has a Mondello cam .544 lift and then he went with a 950cfm holley 3 barrel and full polish and port job on the heads and lots of other goodies and it ran great. then now it has the offy low-rise dual quads with 2 500cfm elderbrocks.
Moral is the motor is balanced for 10grand and the cam setup and everything else is midrange to high range power. This is the power band he wanted and after a lot of researching and figuring out the best combos the big block heads work great with his combination.
So what I am trying to say is if you want your SBO to be a low to mid range power motor then NO to big block heads. But if you want a mid to high range motor and utilize the high revs of the 350 then BBo heads can be benefitial
#10
the motor has Jahn's semi-dome 12:1 pistons and has has the heads milled. Now he has to run 100+ octane to drive it since the heads were milled .01" he use to run Holley street dominator intake and had it port matched with a 780 holley and it ran good with an original W-31 (casting number 194) not an aftermarket W-31 cam. Now it has a Mondello cam .544 lift and then he went with a 950cfm holley 3 barrel and full polish and port job on the heads and lots of other goodies and it ran great. then now it has the offy low-rise dual quads with 2 500cfm elderbrocks.
Moral is the motor is balanced for 10grand and the cam setup and everything else is midrange to high range power. This is the power band he wanted and after a lot of researching and figuring out the best combos the big block heads work great with his combination.
Moral is the motor is balanced for 10grand and the cam setup and everything else is midrange to high range power. This is the power band he wanted and after a lot of researching and figuring out the best combos the big block heads work great with his combination.
#11
i agree with 380 racer on this. you could use those big block heads but you will need higher compression pistons because the big block heads have larger chambers. 83cc i believe. If you do this you will also need a cam change to take advantage of that compression. The cheapest route would be to port the small block heads if more cfm is what your looking for. Unless you are going to be in the higher rpms its not necessary and if that is the case you will need a different cam anyway. little money=little performance
#12
the rotating assembly was balanced for 10 grand. we have the reciept from the machine shop.
a stock assembly balanced won't handle 10,000 so you are giving bad info.
But you read into what you want.
Last edited by Oldsman71; January 29th, 2010 at 04:59 PM.
#13
Cough.......cough. I agree Mark this guy is clueless. That cam will never go anywhere near 10,000 rpms. The 3 barrell carbs were around in the late 60s early 70s and weren't worth a crap. The later HP series are a good carb tho. Either of those intakes need welding and then porting to work with BB heads. It can be done, but I'm not sure you have to wing the SB with the bigger heads either.
WTF??????? you have no idea what you talk about on the intakes. Unless you have personnally tried, you can't comment.
Also never said the cam was good to 10grand but what i did say was it was designed for mid to high range.
#15
the holley street dominator intake has enough material to be raised......got one sitting in the garage and the offy does too it is on the car. Being we have done it sucessfully without welding therefore I speak from experience. Whether or not you believe me, i could care less.
Last edited by Oldsman71; January 29th, 2010 at 05:44 PM.
#16
I HAVE done this swap before with the aforementioned Holley manifold, and if you want the ports to be close to matching, you NEED to weld it up. That is what I did, and was able to get a near perfect match, only after the weld.
The BBO intake port is about .300" taller, and the port in the head is right at the top of the manifold face.
Not welding this manifold really invites a gasket leak on down the road because there is not enough material to support the roof of the gasket.
For anyone doing this swap, you should get a set of Mr. Gasket 404's, and 405's, and put them up on the manifold face.
Do not forget you must open up one of the head locating dowels to fit them onto the block.
That being said, I loved the swap. I had a set of milled "E"'s on a 350 with flat tops, and a 224 cam with a 3.73 gear in a Trans Am, and this thing absolutely woke UP at 3000 rpm. With a stock converter, it would barely squeek the tires loose while power braking it, but it just plain hauled buttocks.
My experience,
Jim
The BBO intake port is about .300" taller, and the port in the head is right at the top of the manifold face.
Not welding this manifold really invites a gasket leak on down the road because there is not enough material to support the roof of the gasket.
For anyone doing this swap, you should get a set of Mr. Gasket 404's, and 405's, and put them up on the manifold face.
Do not forget you must open up one of the head locating dowels to fit them onto the block.
That being said, I loved the swap. I had a set of milled "E"'s on a 350 with flat tops, and a 224 cam with a 3.73 gear in a Trans Am, and this thing absolutely woke UP at 3000 rpm. With a stock converter, it would barely squeek the tires loose while power braking it, but it just plain hauled buttocks.
My experience,
Jim
Last edited by Warhead; January 29th, 2010 at 05:40 PM.
#17
Bottom line people is 455 heads WILL work and if you put together the right combo they will provide performance for you.
Anyone who has heard or seen The Beast, knows.
Anyone who has heard or seen The Beast, knows.
Last edited by Oldsman71; January 29th, 2010 at 06:05 PM.
#19
give bad info huh??????? why be a jerk?
the rotating assembly was balanced for 10 grand. we have the reciept from the machine shop. Then you have a machinist that's full of ****.
a stock assembly balanced won't handle 10,000 so you are giving bad info. I didn't say that. You said it was balanced for 10,000 rpm
But you read into what you want.
the rotating assembly was balanced for 10 grand. we have the reciept from the machine shop. Then you have a machinist that's full of ****.
a stock assembly balanced won't handle 10,000 so you are giving bad info. I didn't say that. You said it was balanced for 10,000 rpm
But you read into what you want.
#20
My dad took the engine to the machine shop and said balance for 10grand and they did that so maybe i can give you the car shop's phone number.
#22
You can if you like, maybe someone here will call them, but I don't enjoy speaking with idiots.
#23
When you here a machine shop say BS that's when you know not to take parts to there shop. I going to give Oldsman71 a brake because he sounds like a young man.
I would say the machine shop only gave a big number because they knew the engine would never see that many rpms. I have heard BS like this from machine shops those guys are only worried about making money.
So if you could give the name of the machine shop so others will know who to stay away from. I don't like to see my friends get ripped off.
P.S. When I find a good machine shop I go back time after time. It's sad when a good machine shop closes or the owner retires.
I would say the machine shop only gave a big number because they knew the engine would never see that many rpms. I have heard BS like this from machine shops those guys are only worried about making money.
So if you could give the name of the machine shop so others will know who to stay away from. I don't like to see my friends get ripped off.
P.S. When I find a good machine shop I go back time after time. It's sad when a good machine shop closes or the owner retires.
Last edited by 70 cutlass s; January 30th, 2010 at 07:11 AM.
#24
I wouldn't doubt for a second he was told 10k. I've met some real arrogant speed shop guys, and lie right to your face engine builders. This thread reminds me of the days when Norm hung out here.
#26
OK.... everybody take a deep breath!
It's possible to disagree without getting into personal insults. The purpose of this forum is to share information with each other. If you find yourself getting angry at a post take the time to have a cold drink and cool off before replying. The strength of this board is having lots of experience and different perspectives on the hobby we share. Lets keep it on a professional level to help not hurt others who enjoy these cars. John
It's possible to disagree without getting into personal insults. The purpose of this forum is to share information with each other. If you find yourself getting angry at a post take the time to have a cold drink and cool off before replying. The strength of this board is having lots of experience and different perspectives on the hobby we share. Lets keep it on a professional level to help not hurt others who enjoy these cars. John
#27
#28
OK.... everybody take a deep breath!
It's possible to disagree without getting into personal insults. The purpose of this forum is to share information with each other. If you find yourself getting angry at a post take the time to have a cold drink and cool off before replying. Good advice.
The strength of this board is having lots of experience and different perspectives on the hobby we share. Lets keep it on a professional level to help not hurt others who enjoy these cars. John
It's possible to disagree without getting into personal insults. The purpose of this forum is to share information with each other. If you find yourself getting angry at a post take the time to have a cold drink and cool off before replying. Good advice.
The strength of this board is having lots of experience and different perspectives on the hobby we share. Lets keep it on a professional level to help not hurt others who enjoy these cars. John
#29
#31
Most Olds V-8 valves are in the ball park of 4.7 inches long, the longest (350 cu in 1.875 intake valve, years 68-72) at 4.74 inches, and the shortest being 4.667 (400, 425, 455-2 inch valve from 68-mid 70's).
It is not difficult for a good, experienced cylinder head grinder to get these to work in other engines if you take some time to do it right.
All of these engines have a set up height that is published yearly (most shops hoard THAT information as if were gold, they do PAY for those numbers), and it is not too hard to get the tip where you need it to be.
Remember, Nick, Mark...if we were doctors, we would need to be accountable for a "bed side manner", so to speak. I too, come off way too grouchy at times, and I am just as bad.
The 10000 rpm comment was probably his dad's slang for "do it right, please-I am going to beat on it" and over time, been taken WAYYYYY out of context. Most factory balance jobs are to a 2 gram tolerance. Fine for 5-6000 rpm's, not for 10 (as if an iron crank, rods and block would ever make it that high in one piece). I have never balanced any crankshafts, so what do I know. Take THAT as you want, but no reason to beat a dead horse.
There is no doubt that his Father put this together as best as HE knew at the time, and if Oldsman wants to update to a Perf Rpm manifold, I am willing to assist, if he wants it port matched. Pm. me if need be.
Jim
It is not difficult for a good, experienced cylinder head grinder to get these to work in other engines if you take some time to do it right.
All of these engines have a set up height that is published yearly (most shops hoard THAT information as if were gold, they do PAY for those numbers), and it is not too hard to get the tip where you need it to be.
Remember, Nick, Mark...if we were doctors, we would need to be accountable for a "bed side manner", so to speak. I too, come off way too grouchy at times, and I am just as bad.
The 10000 rpm comment was probably his dad's slang for "do it right, please-I am going to beat on it" and over time, been taken WAYYYYY out of context. Most factory balance jobs are to a 2 gram tolerance. Fine for 5-6000 rpm's, not for 10 (as if an iron crank, rods and block would ever make it that high in one piece). I have never balanced any crankshafts, so what do I know. Take THAT as you want, but no reason to beat a dead horse.
There is no doubt that his Father put this together as best as HE knew at the time, and if Oldsman wants to update to a Perf Rpm manifold, I am willing to assist, if he wants it port matched. Pm. me if need be.
Jim
Last edited by Warhead; January 31st, 2010 at 05:31 AM.
#33
Most Olds V-8 valves are in the ball park of 4.7 inches long, the longest (350 cu in 1.875 intake valve, years 68-72) at 4.74 inches, and the shortest being 4.667 (400, 425, 455-2 inch valve from 68-mid 70's).
It is not difficult for a good, experienced cylinder head grinder to get these to work in other engines if you take some time to do it right.
All of these engines have a set up height that is published yearly (most shops hoard THAT information as if were gold, they do PAY for those numbers), and it is not too hard to get the tip where you need it to be.
Remember, Nick, Mark...if we were doctors, we would need to be accountable for a "bed side manner", so to speak. I too, come off way too grouchy at times, and I am just as bad.
The 10000 rpm comment was probably his dad's slang for "do it right, please-I am going to beat on it" and over time, been taken WAYYYYY out of context. Most factory balance jobs are to a 2 gram tolerance. Fine for 5-6000 rpm's, not for 10 (as if an iron crank, rods and block would ever make it that high in one piece). I have never balanced any crankshafts, so what do I know. Take THAT as you want, but no reason to beat a dead horse.
There is no doubt that his Father put this together as best as HE knew at the time, and if Oldsman wants to update to a Perf Rpm manifold, I am willing to assist, if he wants it port matched. Pm. me if need be.
Jim
It is not difficult for a good, experienced cylinder head grinder to get these to work in other engines if you take some time to do it right.
All of these engines have a set up height that is published yearly (most shops hoard THAT information as if were gold, they do PAY for those numbers), and it is not too hard to get the tip where you need it to be.
Remember, Nick, Mark...if we were doctors, we would need to be accountable for a "bed side manner", so to speak. I too, come off way too grouchy at times, and I am just as bad.
The 10000 rpm comment was probably his dad's slang for "do it right, please-I am going to beat on it" and over time, been taken WAYYYYY out of context. Most factory balance jobs are to a 2 gram tolerance. Fine for 5-6000 rpm's, not for 10 (as if an iron crank, rods and block would ever make it that high in one piece). I have never balanced any crankshafts, so what do I know. Take THAT as you want, but no reason to beat a dead horse.
There is no doubt that his Father put this together as best as HE knew at the time, and if Oldsman wants to update to a Perf Rpm manifold, I am willing to assist, if he wants it port matched. Pm. me if need be.
Jim
We try to get street balance jobs just under 2 grams as you stated and competition jobs at .5 gram.
#34
Well put captjim and Warhead. I know I have never built an engine that turned ten grand. Even when I ran Chevy engines most I every had one up to was 7,500. The cost of building an Chevy engine to run in that ten grand rpm range was out of my price range.
#38
Far as the RPm manifold no thanks this setup is working just great with the E heads.
Next time I am down at my dad's I will get a pic of the holley manifold and do some comparision pics.
#39
Oldsman71, nice looking engine compartment. Do you have more photos of your car posted elsewhere? Most of the time new members are asked to post pictures of their cars so we can all enjoy them. If that hasn't happened yet would you create a new thread showing us your car and telling us more about it? John
#40
Oldsman71, nice looking engine compartment. Do you have more photos of your car posted elsewhere? Most of the time new members are asked to post pictures of their cars so we can all enjoy them. If that hasn't happened yet would you create a new thread showing us your car and telling us more about it? John