How efficient is a VJ in a boosted application?
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How efficient is a VJ in a boosted application? I am putting together a motor combo to go with TT's and I'm wondering if you guys think I might gain either efficiency or power by doing some light bowl blending and a good 3 angle valve job on a set of milled 317 heads?
I think it would gain all over the board in both efficiency and power. I have been told most of the power in head porting is from a good valve job anyways, anything extra from blending the bowls would only add to the benifits of the VJ.
I know crazy power can be made on stock heads. I personally made 676rwhp with stock 241 heads on an old Procharged set up. That being said. I don't think something as minimal as just a valve job is going to net you a big gain on a FI set up. obviously there will be more power had from porting the heads as well.
If you are going to pay for a valve job and some bowl work you may as well just have them do some minor clean up the the runners. I think it would be worth it.
If you are going to pay for a valve job and some bowl work you may as well just have them do some minor clean up the the runners. I think it would be worth it.
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I know crazy power can be made on stock heads. I personally made 676rwhp with stock 241 heads on an old Procharged set up. That being said. I don't think something as minimal as just a valve job is going to net you a big gain on a FI set up. obviously there will be more power had from porting the heads as well.
If you are going to pay for a valve job and some bowl work you may as well just have them do some minor clean up the the runners. I think it would be worth it.
If you are going to pay for a valve job and some bowl work you may as well just have them do some minor clean up the the runners. I think it would be worth it.
I've read that doing a really good 3-angle valve job in conjunction with porting, that the majority of the flow/power comes from the valve job itself. That's one of the reasons I've thrown this thread out there.
opening up the ports never hurts, a fancy valve job on forced induction motor doesn't do alot though. once your in to boost it doesn't really care, it's going to push the air in no matter what the valve job is. does it make more, a little, but not enough that i'd spend real money on it.
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opening up the ports never hurts, a fancy valve job on forced induction motor doesn't do alot though. once your in to boost it doesn't really care, it's going to push the air in no matter what the valve job is. does it make more, a little, but not enough that i'd spend real money on it.
It may be far better to spend the money on porting the LS2 intake. I know these things don't flow for ****.
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I have read some stuff about guys running a 50-55 degree valve seat on the exhaust side of a turbo setup. I'm not 100% sure on the theory but I believe the 50+ valve angle kills low lift flow (.200-.400) lift and helps cut back on the over scavenging the port during the overlap period. This supposedly can help reduce back pressure and increase spool on a turbo setup. No doubt there are nice gains to be had in the proper valvejob. With that being said I honestly don't feel too many people have any clue about what a proper valve job is. I can tell you it's not the standard 30-45-60 angles.
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I have read some stuff about guys running a 50-55 degree valve seat on the exhaust side of a turbo setup. I'm not 100% sure on the theory but I believe the 50+ valve angle kills low lift flow (.200-.400) lift and helps cut back on the over scavenging the port during the overlap period. This supposedly can help reduce back pressure and increase spool on a turbo setup. No doubt there are nice gains to be had in the proper valvejob. With that being said I honestly don't feel too many people have any clue about what a proper valve job is. I can tell you it's not the standard 30-45-60 angles.
anything that promotes airflow in a cylinder head is good whether it be an n/a engine or fi. Anybody who thinks that good port work and good valve jobs on forced induction is a waste is sadly mistaken. Anytime you increase the efficiency of an engine , you increase power and wear and tear on the engine
Thread Starter
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From: Shreveport, Louisiana
anything that promotes airflow in a cylinder head is good whether it be an n/a engine or fi. Anybody who thinks that good port work and good valve jobs on forced induction is a waste is sadly mistaken. Anytime you increase the efficiency of an engine , you increase power and wear and tear on the engine
Now I'm sure you have your builder secrets, but could you advise us [me] on any angles I should stay away from? ie - Standard valve job vs. competition valve job?
sorry for rambling
