plentum and intake questions

[G Winter]

In the very near future, maybe this week, I need to pull the intake off of my 90 L98 because it developed a nasty oil leak at the back. I need some opinion on whether or not it is worth the time to polish and do a little matching of the runners and plentum. I have seen that people have done this but really haven't seen if there were positve results. As far as I know everything is stock on this engine. Cleaning the throttle body, new radiator hoses and thermostat are also on the list. Is it also wise to replace the EGR valve at this time? A second thing, has anyone ever removed the front crank seal without removing the cover. I used to do it on the older chevy V8s but not sure if I would have a chance damaging the front cover on my L98. While I am at the intake I plan on pulling the radiator to make sure there are no blockages from leaves etc. While I am that far if I can get by with pulling the front seal I would also replace that but really am not in the mood for dropping the pan.
EGR in mind , the car has about 74 k on it . I have another car with over 200k on it and never had to replace it.

 

[Vettefan87]

I would definetly do a little porting, and polishing on the plenum and runners, every little bit helps. As for replacing the EGR you could, This last time my motor was out I replaced mine even though it was not bad. Knowing my luck it would have just went out within a week that I had gotten everything back together. :L

 

[Moonunit 451]

I would definetly do a little porting, and polishing on the plenum and runners, every little bit helps. As for replacing the EGR you could, This last time my motor was out I replaced mine even though it was not bad. Knowing my luck it would have just went out within a week that I had gotten everything back together. :L

I agree G - man If you've got the time, try to find info on Siameasing (? sp) the runners. Get the dremel out and the wet dry sandpaper and grind and polish the hell out of it Through some Rocker Rollers in there while you're at it and you WILL get some more HP and seat of the pants improvements :cool

 

[Vettefan87]

I agree G - man If you've got the time, try to find info on Siameasing (? sp) the runners. Get the dremel out and the wet dry sandpaper and grind and polish the hell out of it Through some Rocker Rollers in there while you're at it and you WILL get some more HP and seat of the pants improvements :cool

I agree, I forgot about the RR's. Don't go with anything but 1.6. Mad-Mic recommends Harlans, I think they are around 200 from Jegs.

 

[Edmond]

Yeah, change the EGR while you're at it. You don't want to have to take the plenum off to change that thing. It can get to be a PITA. Just do it when the runners are off so you can easily get access to the EGR nuts, which are 3/8"

 

[G Winter]

Found out today that EGR cost right at $60 :ugh Bottom radiator hose.. $32
didn't know a hose could cost that much. Sure not gonna have the system drained and radiator out and not put that one on. Just not real sure about that EGR yet.I am not planning on pulling the valve covers, so don't think rockers are in the plan. I don't need to go $200 faster. Whats this about siamesing runners ? I have been away from this preformance thing for a few yrs.

 

[bossvette]

I don't think you can siamese stock runners here is a picture of SLP runners siamesed not a very good picture but you can get the idea of what it is.

 

[89vert]

How much time and money do you have? One thing that I have been thinking about is having my base extrude honed. It will cost less than a new base with the same effect. Don't do to much to your stock runners there is no room to port. If you want to do something with the runners buy aftermarket.

 

[Edmond]

$32 for a lower radiator hose? From who? It must be the dealer! I could buy both the upper and lower radiator hose for $32 and still have change left over.

That sounds about right for the EGR. But think about the work you'll have to do if it needs to be changed by you.

 

[Vettefan87]

I wanted to say when I priced them out from Auto Zone they were 30 for the upper and lower like Edmond said.

 

[Moonunit 451]

I don't think you can siamese stock runners here is a picture of SLP runners siamesed not a very good picture but you can get the idea of what it is.

Boss, that is the nastiest looking pic of siamesing that I have seen :W I'm sure that is not your work If I get the time I'll try to find some more info on the proceedure.

 

[bossvette]

Actually that picture was taken with a low res digital camera after hogging out with a carbide burr. The base was done by Greenwood Corvette and is finished in this picture. What many people don't realize is that TPI and other EFI manifolds are "dry" and do not need a very high polish to be effective; just smoothed out and obstructions removed. I should have taken a picture when it was finished but didnt.

 

[G Winter]

$32 for a lower radiator hose? From who? It must be the dealer! I could buy both the upper and lower radiator hose for $32 and still have change left over.

That sounds about right for the EGR. But think about the work you'll have to do if it needs to be changed by you.

Actually they alwasy tell me list price. They never charge me anywhere near list price. The upper hose list for $17 so by the time I get my discount It won't be anywhere near that much . Same goes for the EGR. The felpro intake gasket set list for $45.99 my cost $33.99 . I haven't found anyplace around here that sells any cheaper and online the shipping eats up the diff.
Thanks everyone for the input so far. The weather isn't warming up much yet so I think it will be next week before I go at this.
Additional question... Plastic verses steel tensioner pully. I know the plastic have been known to wear through. will the steel wear the belt ?