Porting and Swapping A New Intake Manifold This Week.

[LargeOrangeFont]

I have some time this week so I picked up a new intake manifold for the LS1 in my
RX7 to get a bit more power and also to step up to a 90mm throttle body. It has an LS6 intake manifold now with a ported stock throttle body. I got one of the new Dorman “LS2” intakes that is a $900 FAST intake copy, for under $400.

The intake is decent but has some room for improvement in the finish department, so I decided to clean up the inside.

Mocked up with a Holley 90mm throttle body I have had in stock waiting for and intake.

The throttle body opening matches the intake really well

Intake runners need some cleanup. I’ll be removing that step on the lower left of each runner and cleaning up all the edges.

This is a multi piece intake that is bonded together. There was a 1/4” gap in the throat of the intake where the upper an lower halves come together. I smoothed the throat area a bit and then filled the gaps with epoxy. I will now be able to smooth this transition.

Much smaller gap on the top side, this needed just a thin bead of epoxy. I also ground off a hump that was a boss for a bolt.

So I’m letting all the epoxy dry overnight. I’ll smooth out the all intake runners tomorrow and finish up the throat area. Then it will be ready to clean and install. More pics to follow.

 

[Cray Paper]

Same as it has always been, just smaller gains. Isnt the LS3 intake / injectors / TB a huge improvement over the LS1 stuff?

 

[Bowtiepower00]

Have you made an in-depth thread on your RX7? Looks like an awesome ride... I've read bits and pieces in several posts but don't recall a build thread...

 

[LargeOrangeFont]

Yea the LS3 intake is pretty good. The original LS1 intake is not great, the LS6 intake is pretty good for the cathedral port stuff, but you are limited to the 78mm throttle bodies.

The FAST intakes work very well for all port styles, but are around $900. This intake is a copy of a FAST lower, a LS6-like upper but with a 90mm throttle body provision, for less than half the price.

 

[LargeOrangeFont]

Have you made an in-depth thread on your RX7? Looks like an awesome ride... I've read bits and pieces in several posts but don't recall a build thread...

I haven’t but I can do a build review soon. It is a pretty fun car. I am finally going to get it repainted in a month or two.

It was also featured on a One Take with Matt Farah on his You Tube channel The Smoking Tire.

 

[Cray Paper]

Yea the LS3 intake is pretty good. The original LS1 intake is not great, the LS6 intake is pretty good for the cathedral port stuff, but you are limited to the 78mm throttle bodies.

The FAST intakes work very well for all port styles, but are around $900. This intake is a copy of a FAST lower, a LS6-like upper but with a 90mm throttle body provision, for less than half the price.

I'm remembering back several years ago when my brother built his 402 LS2 based stroker. He was stoked with the MAST ported LS3 heads, intake, injectors, rockers? and TB. Said you couldnt beat them for the price. His car ran fucking hard until last year, I think he put around 90K on that 402, beating the shit out of it the whole time.

 

[LargeOrangeFont]

I'm remembering back several years ago when my brother built his 402 LS2 based stroker. He was stoked with the MAST ported LS3 heads, intake, injectors, rockers? and TB. Said you couldnt beat them for the price. His car ran fucking hard until last year, I think he put around 90K on that 402, beating the shit out of it the whole time.

Mine is a slightly bored LS1 with forged pistons. Stock LS1 heads at the moment, but the valvetrain is highly upgraded. I have some NASCAR take off LS6 heads going on after I do this intake.

For the smaller bore stuff the LS3 rectangle port induction setups don’t buy you anything.

 

[rvrrun]

That looks like a piece of cake. I still feel the aluminum chips down my sleeves from all the heads I ported.

 

[rvrrun]

I haven’t but I can do a build review soon. It is a pretty fun car. I am finally going to get it repainted in a month or two.

It was also featured on a One Take with Matt Farah on his You Tube channel The Smoking Tire.

Post a link.

 

[LargeOrangeFont]

That looks like a piece of cake. I still feel the aluminum chips down my sleeves from all the heads I ported.

I can still smell the cast iron dust in my nose as well.

 

[LargeOrangeFont]

Post a link.

I can do a little more detailed write up on the build, but here is the video.

Here is a video of the car at a track event at AAA Speedway last year, I was giving ride alongs all day.

 

[Guest06]

Mine is a slightly bored LS1 with forged pistons. Stock LS1 heads at the moment, but the valvetrain is highly upgraded. I have some NASCAR take off LS6 heads going on after I do this intake.

For the smaller bore stuff the LS3 rectangle port induction setups don’t buy you anything.

NASCAR LS6 heads??? Are they GM cast #’s what are they and when was the LS base used in Nascrap?? I know one thing heads on these LS based motors are iNsAnE i did wcch stage III 243’s on my car and holy hell now there stage II is considered stage 1 and what i have is there stage II today. One day I’ll find a bare LS2 block and do my 408” or maybe a 416 if i find a LS3 block but what I’ve read the 408 really does well with my heads as the 416 really needs the bigger rectangular heads.
The crazy part of these motors is it’s all about the heads, you take the 350-355” sbc you’d have to have big compression big fuel and 5k heads to compare.

I have the FAST LSXr 102 intake with the neck down ring and FAST 92tb really curious once you get down on that intake how it looks and runs against the old LS6 intake. Please keep updated on it as i went from an LS2 intake (biggest pos GM ever made) and a China 90, to my FAST intake and tb with dramatic seat of the pants difference. One day I’ll get it all tuned and for sure see more as well.

 

[LargeOrangeFont]

NASCAR LS6 heads??? Are they GM cast #’s what are they and when was the LS base used in Nascrap?? I know one thing heads on these LS based motors are iNsAnE i did wcch stage III 243’s on my car and holy hell now there stage II is considered stage 1 and what i have is there stage II today. One day I’ll find a bare LS2 block and do my 408” or maybe a 416 if i find a LS3 block but what I’ve read the 408 really does well with my heads as the 416 really needs the bigger rectangular heads.
The crazy part of these motors is it’s all about the heads, you take the 350-355” sbc you’d have to have big compression big fuel and 5k heads to compare.

I have the FAST LSXr 102 intake with the neck down ring and FAST 92tb really curious once you get down on that intake how it looks and runs against the old LS6 intake. Please keep updated on it as i went from an LS2 intake (biggest pos GM ever made) and a China 90, to my FAST intake and tb with dramatic seat of the pants difference. One day I’ll get it all tuned and for sure see more as well.

They are Wegner CNC ported 243/799 castings. In the Canadian Tire/K&N series they used a sealed spec carbureted LS2 that makes 610 HP and 500 ft lb of torque. There is special QR style coding on all the parts to verify they are correct and not tampered with.

http://www.enginelabs.com/news/despite-controversy-nascar-spec-engine-a-viable-option-for-racers/

Anyway the heads have to maintain a 64cc chamber, so the heads can’t be milled at all so they get sold off. Guys buy them for cheap and do a quick valve job and clean up the decks and they are ready for a new life.

The NASCAR spec heads are CNC ported 243/799 castings with stock sized Del West titanium valves in the intake and exhaust with PSI valve springs. I got them fresh from the machine shop and ready to go on the car for like $1200 shipped.

So between the heads and the intake/90mm TB upgrade I am expecting about 40 WHP, but I am going to do this intake first just to see how it works by itself. I am certain I’ll have to touch up the tune a bit after I get this intake setup on.

I had a FAST 90 I just sold and never put on the car. I was not super enthusiastic about using it because I’d have to change my entire fuel rail setup to run it. The reason I wanted to try this Dorman intake was because it is similar to the FAST, but my fuel rail will go right on it without modification.

 

[Guest06]

They are Wegner CNC ported 243/799 castings. In the Canadian Tire/K&N series they used a sealed spec carbureted LS2 that makes 610 HP and 500 ft lb of torque. There is special QR style coding on all the parts to verify they are correct and not tampered with.

http://www.enginelabs.com/news/despite-controversy-nascar-spec-engine-a-viable-option-for-racers/

Anyway the heads have to maintain a 64cc chamber, so the heads can’t be milled at all so they get sold off. Guys buy them for cheap and do a quick valve job and clean up the decks and they are ready for a new life.

The NASCAR spec heads are CNC ported 243/799 castings with stock sized Del West titanium valves in the intake and exhaust with PSI valve springs. I got them fresh from the machine shop and ready to go on the car for like $1200 shipped.

So between the heads and the intake/90mm TB upgrade I am expecting about 40 WHP, but I am going to do this intake first just to see how it works by itself. I am certain I’ll have to touch up the tune a bit after I get this intake setup on.

I had a FAST 90 I just sold and never put on the car. I was not super enthusiastic about using it because I’d have to change my entire fuel rail setup to run it. The reason I wanted to try this Dorman intake was because it is similar to the FAST, but my fuel rail will go right on it without modification.

What heads do you have now? If stock LS1 I’d assume you’d see 40hp from a stock 243/799 and that intake. If those heads are 5 axis cut as well different valves and a 62cc chamber as they were most likely needing a trim they should make 40 themselves

 

[LargeOrangeFont]

What heads do you have now? If stock LS1 I’d assume you’d see 40hp from a stock 243/799 and that intake. If those heads are 5 axis cut as well different valves and a 62cc chamber as they were most likely needing a trim they should make 40 themselves

Yea the heads were 5 axis cut and milled slightly. I had Clay Smith Cams inspect them just to be sure and they said they were ready to bolt on and were everything that was stated.

I have stock LS1 heads now (241 casting) and a stock LS6 intake with ported stock throttle body.

I have a mild cam by today’s standards. I run the GM ASA cam - 226/236 .525/.525 lift with 110 LSA. This is the same cam GM puts in the LS376/525 HP crate LS3. It is literally a stock LS3 with the cam only, and it makes 95 HP over a stock LS3. I really like this cam because it is easy on the valve springs and has a really wide powerband.

Car makes 401/401 to the tires now. It does not sound like a lot but it is a 2600 lb. car. It will pull away from new Vipers, Porsche GT3s, and modded Z06 Vettes on the straights. It really does not need anymore power.. I don’t even know why I’m doing this .

The only street-able cars that have driven away from me on the straights of a race track were a 735 WHP GTR and a 700 WHP 991 Porsche GT2 clone with a sequential transmission. Everything else I can pretty much hang with.

 

[LargeOrangeFont]

Epoxy set up nicely overnight. Went out this morning and did the final rough in with 60 grit. It is coming out well so far. In that bottom pic you can see how wide that gap was that I filled with epoxy.

I need to run to Home Depot to get some 120 and 240 grit sanding drums to finish it up. Then I’ll start on the runners, those should go pretty quick.

 

[LargeOrangeFont]

Here are some pictures of the heads. You can see the spec verification markings in the intake port.

 

[Cole Trickle]

Looks good....

Man you have a lot of car project stuff stacked in the garage. Time to get after it in 2018 and make them all faster[emoji41][emoji106]

B interested in the ls6 intake if the price is right. Still need to sell off my ls3 intake/fuel rail and injectors if you know anyone looking.

 

[LargeOrangeFont]

Looks good....

Man you have a lot of car project stuff stacked in the garage. Time to get after it in 2018 and make them all faster[emoji41][emoji106]

B interested in the ls6 intake if the price is right. Still need to sell off my ls3 intake/fuel rail and injectors if you know anyone looking.

Yea.. too much I’ll let you know on the LS6 intake. I might be building another engine as a spare for some other project if I can find a short block priced right. I already have yet another set of stock 243 heads I got for a stupid deal before I bought the NASCAR ones.

When I swap these heads I’m going to take the Comp dual springs off my current 241 heads and put them on those 243s and have them freshened up.

When everything is working well I’d rather drive it then pull it apart and mess with it. I need to get a couple upgrades done to the RX7 this spring though. It is ready for some aero mods, paint, and I need to get bigger rear brakes on it.

I also just signed up for a 24 Hours of Lemons race in AZ in Feb. I don’t have to do any work for that though, just show up and drive

 

[Cole Trickle]

Yea.. too much I’ll let you know on the LS6 intake. I might be building another engine as a spare for some other project if I can find a short block priced right. I already have yet another set of stock 243 heads I got for a stupid deal before I bought the NASCAR ones.

When I swap these heads I’m going to take the Comp dual springs off my current 241 heads and put them on those 243s and have them freshened up.

When everything is working well I’d rather drive it then pull it apart and mess with it. I need to get a couple upgrades done to the RX7 this spring though. It is ready for some aero mods, paint, and I need to get bigger rear brakes on it.

I also just signed up for a 24 Hours of Lemons race in AZ in Feb. I don’t have to do any work for that though, just show up and drive

Try to get into the seat early before the car blows up...lol

We have talked about putting a car together for lemons. still a bunch of $$ and time to do it right.

I should find a cheap ly6 and build something to stab in my camaro.....nothing crazy just cam/springs and throw on the ls3 intake I have.

 

[LargeOrangeFont]

Try to get into the seat early before the car blows up...lol

We have talked about putting a car together for lemons. still a bunch of $$ and time to do it right.

I should find a cheap ly6 and build something to stab in my camaro.....nothing crazy just cam/springs and throw on the ls3 intake I have.

No kidding. These guys have completed 3 races so the car is sorted.

Yea I have wanted to put one together as well, but storage is the problem. I think it is actually better to just buy a completed car and make sure it is sorted out. We wanted to do a Fairmont or an RX7. Either with a SBF Ford in it

Yea I am hoping to find an bare L33 or Lc9 aluminium 5.3 and punch it out to 5.7L, or a bare LS1 block and go from there.

 

[Guest06]

Why not look for an LS2 block instead for a new build? Another one that would be wicked fun for that little car is build an LS1 with the L33 bottom end, destroked rev beyond the moon motor.

 

[LargeOrangeFont]

If I find an LS2 block for the right money, sure I’d do it. You can find the aluminium 5.3 truck blocks for ~$300 typically, and they can be bored to a stock LS1 bore. People want $$$ for LS2 and newer stuff.

Right now I shift at 6600-6700 generally. Rev limiter is 7100 so I can hold a gear into a corner if needed. There is always a corner or two on every track where I need to run it close to 7000.

The 5.3 would soften my midrange power most likely. Right now It can take all I can give it on a hard corner exit... It will carry the inside front wheel.

 

[Vabowtie]

Hey guys, I’m new to this forum so forgive me for jumping in on this older Post, but I am doing a similar swap myself and was wondering what kind of Epoxy was used? My engine builder is concerned about epoxy letting go and getting sucked into the cylinder? Any help would be greatly appreciated. Thanks

 

[HOOTER SLED-]

You have an "engine builder" that doesn't know that already? Maybe it's time for a new engine builder....just a thought.

 

[LargeOrangeFont]

Hey guys, I’m new to this forum so forgive me for jumping in on this older Post, but I am doing a similar swap myself and was wondering what kind of Epoxy was used? My engine builder is concerned about epoxy letting go and getting sucked into the cylinder? Any help would be greatly appreciated. Thanks

2 part, 5 min epoxy from Home Depot Racing, nothing special. It will never touch fuel in that area, so pretty low risk.

I never did get this intake installed. I need to modify the back of the intake to clear the firewall, and will be using more epoxy or JB weld for that.

 

[wzuber]

Hey guys, I’m new to this forum so forgive me for jumping in on this older Post, but I am doing a similar swap myself and was wondering what kind of Epoxy was used? My engine builder is concerned about epoxy letting go and getting sucked into the cylinder? Any help would be greatly appreciated. Thanks

If your really worried about epoxy failure use "sea goin" epoxy (p/n-1350 k3) It's commonly used to set intake adapters in jet boats and is incredibly durable as well as highly chemical resistant. It's likely a bit over kill but piece of mind usually is. I suspect most failures in this type of application are due to improper preparation and or application (mixing etc.) of the epoxy itself and not a actual "material" failure. JMO tho.

 

[rvrrun]

2 part, 5 min epoxy from Home Depot Racing, nothing special. It will never touch fuel in that area, so pretty low risk.

I never did get this intake installed. I need to modify the back of the intake to clear the firewall, and will be using more epoxy or JB weld for that.

I can't see it ever being a problem. The 325hp oval ports in my El Camino were mated to an LS6 rect port manifold. I raised the floors with A/B putty and never had a leak or anything dislodge. I used rect port gaskets and all was fine.

...and dynoed just under 400hp

 

[LargeOrangeFont]

I can't see it ever being a problem. The 325hp oval ports in my El Camino were mated to an LS6 rect port manifold. I raised the floors with A/B putty and never had a leak or anything dislodge. I used rect port gaskets and all was fine.

...and dynoed just under 400hp

Yes. If you were gonna run E85 and it was gonna be in contact with the fuel I might use a different product.

 

[Vabowtie]

Yes. If you were gonna run E85 and it was gonna be in contact with the fuel I might use a different product.

You have an "engine builder" that doesn't know that already? Maybe it's time for a new engine builder....just a thought.

Sorry, that was my engine builders concern, but probably because I am doing the intake work myself. I just wanted to make sure that I was using something strong, flexible enough to not crack, fuel resistant, grindable and heat resistant....and anything else I may not have thought of. Thanks for all of the good feedback.