Stroker 304 Project Build

[jeepjerry]

Yeah Nick builds some pretty hefty engines. You wont see a Street Dominator going down the drag strip on one of his engines.

I know him pretty well, I work for him a few days a week on his cars and customer cars. Right now we're working on his 74 Gremlin X cleaning up the engine compartment to paint before we put the 258 that we built up into it. Its very cool to work with him and learn the gobs of engine knowledge he has. Cant wait til we get his 71 AMX together with his 13:1 compression 401 that should make a streetable 650-700 hp. That will be sweet..

Thats a pretty interesting carb there, ive never heard of it. They should get more popular due to the fuel mileage they can achieve.

[Greg Taylor]

Originally Posted by jeepjerry

Thats a pretty interesting carb there, ive never heard of it. They should get more popular due to the fuel mileage they can achieve.

Yes, the Fish is pretty interesting. The original designs (M1 & M2) only has about 17 parts, 3 of which move. The newer design (M3) that I have will have about 22 parts and perhaps 5-6 that move.

I still considering getting the motor dynoed with a Holley or Edelbrock 4-bbl on it, and then switching to the Fish carb(s) for an apples-to-apples comparision. The Fish Carb was typically known for getting 30% more power and 20% better gas mileage, so a dyno would show the power increase.

[Greg Taylor]

Hey guys,
Here are more pics of the build-up. We'll be doing more work this Saturday, so I hope to post more Sat evening.

[Greg Taylor]

Hey guys,
Here are pics of the heads, with the 1.94/1.50 SB Chevy valve conversion.

[dd76522]

quick random thought....did you consider a roller cam? a custom ground roller would have definetly cost more but i'd be willing to bet it would have been worth it

[Greg Taylor]

I had, but didn’t want to invest that much more $$$ into the engine ($800 more) … I’m already at cubic dollars as it is, LOL!

[tgreese]

I take it these are 304 heads with the oversize valves. The Chevy valves clear the cylinder bores? My BOTEC says that they will collide with the 304 bore - maybe they clear if you're 80 over? Could you have relieved the cylinders and used 360 heads instead?

<read your description again - so these are 360 heads with undersized valves? What's the advantage of these heads over the 304 heads with the same SBC valves?>

[Greg Taylor]

The 1.94/1.50 valves clear the overbore. On a stock bore, the exhaust valve has to be cut down to a 1.45” to clear the bore … the exhaust valves are closer to the bore wall, than the intakes are. ON the 0.080” overbore, I could have run a 2.02” intake valve, but not a 1.60” exhaust valve … the exhaust would have needed the bore relief notch. Also, the 2.02” intake would have reduced port velocity, decreasing torque and MPGs.

The 1.94/1.50 combo WITH THE UNDERCUT VALVE STEMS, is an excellent upgrade over the stock AMC 1.787”/1.406” valve sizes. With the smaller valve stem diameters (5/16” in the runners due to undercut) they flow about 40% more at lower RPMs, which decreases as RPMs increase (negligible difference at 5,000 RPM). This added flow at low-mid RPMs makes a HUGE difference in torque, power and MPGs.

I did the 1.94/1.45 combo on the head for my ’83 Spirit GT (258 4-speed) and it was night and day. It made the stock 258 perform and feel like a 4.0L HO was under the hood. I would estimate I picked up about 30 HP and at least that much torque, just with the SBC valve swap.

These heads are AMC R&D 360 heads. They had 1.787” intake valves and 1.68” exhaust valves installed, and a swirl-port design. AMC was testing them out to see how emissions and MPGs could be improved with a lean-burn swirl-port design. I had hardened valve seats installed on the exhaust side, so that the smaller 1.50 diameter valve head could be used.

You can also do the 1.94/1.50 swap on the 304 heads. FYI, a 1.94/1.60 swap on the 304 heads is really good for a street/trail 360. Low-Mid RPM torque and MPGs is increased, due to the higher port velocity with the smaller 1.94 valve (as compared to the 2.02 360/401 intake valve).

[jeepjerry]

Greg, you've got some great information here. Keep sharing your knowledge..

Whats the deal with that SC/Rambler you got there?

[Greg Taylor]

Originally Posted by tgreese

My BOTEC says that they will collide with the 304 bore

What is a "BOTEC"? Thanks.

[tgreese]

back of the envelope calculation

[red mistress]

Originally Posted by jeepjerry

Greg, you've got some great information here. Keep sharing your knowledge..

Whats the deal with that SC/Rambler you got there?

Greg also appreciate the AMC 327 info, you're a walking encyclopedia.

I also saw the SC Rambler Scrambler and the dealership signs around the shop. Looks like cool place to hang out.

[Greg Taylor]

Originally Posted by red mistress

Greg also appreciate the AMC 327 info, you're a walking encyclopedia.

I also saw the SC Rambler Scrambler and the dealership signs around the shop. Looks like cool place to hang out.

You're welcome for the info. The AMCs are my buddy's. He's helping me build the engine. He's got some sweet AMC stuff ... and knows his stuff about putting together a GOOD AMC engine.

[tgreese]

Keep posting Greg - we (I) appreciate the info, and this is an interesting project.

[Greg Taylor]

Hey guys,
We worked on the build more on Saturday, pics are attached.
I modified the Offy 360 intake for use with the Fish carburetor, cutting the plenum devider down about 1.25" to help better divert the air flow, since the 1-barrel fish is positioned directly over the divider.

We also ran into some 'speed bumps' with parts that don't fit or don't fit without more modifications needed. My new 8-qt oil pan didn't fit over the front/rear main caps, even with a little 'help' the bolt holes were off by 1/2 hole. So we're going with an NOS Jeep oil pan that fits fine.


The Milodon head studs are too long on the exhaust side (3 places) and hit the header flanges. The bolts for the head studs are too large in between the rocker pedestal embosses and a socket won't fit down in there. It would require taking the heads off and grinding or milling the embosses for clearance. I opted to order new ARP head BOLTS from Summit Racing.

We also checked the difference between the OEM timing cover from my 360 (circa 1995 manufacture by Mopar) and the new aftermarket Crown cover. The Crown cover still has the distributor fitment issues, which requires some massaging of the cover to get a distributor to fully seat properly and mesh with the cam gear. I'll get pics of that up later. I'm going to run the OEM cover since it is in such good shape ... and my cam/dist. gears will appreciate the better fitment of OEM.

Also, I have pics of the ROL Xtreme 360-401 head gasket vs. the Felpro HiperBlue 304 gasket. I'm going with the 304, since it better fits the bore diameter. I'll end up with aboug 10.2:1 compression with it, as opposed to 9.95:1 with the ROL gasket.

I have also decided to NOT USE the Holley Street Dominator. It's a great intake, but it looks like the smaller runner placement won't work well with the Swirl-Port head design. So, I am going with the Offy 360 Q-jet intake.

Here are pics.

[red mistress]

Please tell us which MFG. oil pan is so wrong that the holes don't line up.

[Greg Taylor]

Originally Posted by red mistress

Please tell us which MFG. oil pan is so wrong that the holes don't line up.

I'm currently working out the refund details with the MFG of that oil pan, so I don't want to just post up that info yet. Stay tuned ...

[jeepsr4ever]

Originally Posted by red mistress

Please tell us which MFG. oil pan is so wrong that the holes don't line up.

Its our pan its a Bulltear 8qt oil pan. We have now had 2 like this that have had bending issues after plating. We may discontinue the .100" thick crash pan in favor of a .060 8qt pan and a low profile road race pan. Greg is sending it back in so we can take a look and make sure it never happens again. Great buildup so far

[red mistress]

Originally Posted by jeepsr4ever

Its our pan its a Bulltear 8qt oil pan. We have now had 2 like this that have had bending issues after plating. We may discontinue the .100" thick crash pan in favor of a .060 8qt pan and a low profile road race pan. Greg is sending it back in so we can take a look and make sure it never happens again. Great buildup so far

That's great committment to customer satisfaction.
Owning up to mistake and determined to solve the problem for future customers.

I would of bet it was a Milidon pan, I bought 2 or 3 before I could get one that would fit and seal everywhere. Went round and round with Summit sending them back and ordering again....

[Greg Taylor]

Originally Posted by red mistress

That's great committment to customer satisfaction.

Yeah, Matt has been really great about this, working to get it resolved. Thanks, Matt!