Heat crossover, how they work and why I hate them.

How to block a heat cross over.

[@MrWill73]

Great tip that a lot of people forget about👍👍👍

[@anythinggoesgarage5943]

I've seen lead in sbc heads for racing. I use the heat risers in my sbc's. If they work properly it works. I got a 37 Pontiac that one got stuck and it boil the fuel after you shut it off. They repop the heat valves now for a lot of stuff but like you said if it's a summertime car you don't need it!

[@AndyGeesGarage]

This is precisely what JB weld is for, anchoring these plugs and other repairs in high heat applications. I got that straight from the Justice Brothers themselves. Another thing their products are good for is reinforcing valve spring pockets after heads have been hogged out a bunch you “glue” a washer into the spring pocket, increases installed spring pressure too. All stock car racing tricks when you have to use factory parts.

[@wildrosegarage4208]

Makes sense, good tricks I don't no how JB weld would hold up to the heat I thought it was rated for only 350f.

[@trentdawg2832]

I think its a joke😂😂😂

[@AndyGeesGarage]

@@wildrosegarage4208 extreme heat jb is good to 1000* F

[@paintnamer6403]

Ford also made a 4bbl carb spacer that coolant flowed through. There is an inlet and outlet for hearer hoses. I think it came from a late '60 pickup with a 390

[@wildrosegarage4208]

Actually that would be a okay setup. You could put a valve on it and close it and open it up in the coldest days of winter. I had two 71 fords one with a 390fe one with a 360fe and they did not have it. My buddy has a 66 with a 352fe his does not have one as well. Thanks for watching.

[@dartvader9939]

I also have intake and carb from a early sixties 390 t-bird had coolant lines ran into it! Replaced it with a Edelbrock for sale if someone wants a og setup

[@moparnut6286]

All valid points to get rid of the heat crossover.... Unless you live where it's really cold all year long it serves no good purpose...only my truck uses the cross over since it is the winter tow all home...but the heat riser is deleted and I use a 1 inch swirl carb adapter which makes the 318 start easy in summer never has vapor I lock issues.

[@markg7030]

This is a very good street/strip trick.

[@Jeremy-iv9bc]

You need it because carbs are shit and the fuel will pool in the cold intake manifold.

[@wildrosegarage4208]

Really strange, I have had them plugged my entire life even when driven in the winter at -30 I have never had a issue. Probably because warm coolant runs through the intake. Lots of performance intakes do not have a crossover and a lot of factory intakes have been plugged with carbon for the last 30 years and it doesn't function but run great.

[@dartvader9939]

Yes sir weld that up if you don't have the funds for a intake

[@wildrosegarage4208]

Actually a lot of intakes still have the crossover Edelbrock performer and rpm for example.

[@kevinhawley962]

egr valve basically old 1980 datsun 510 had this deleted it went got a 32/36 weber clone never looked back

[@SweatyFatGuy]

I've noticed a 4mpg difference on E85 between heat crossover blocked and open, it gets better mileage with the heat. The fuel vaporizes better and faster with the hot intake, the heads I have on the 65 right now have the crossover blocked because they were my race heads in the 90s running race gas. The heads I had on before do not have it blocked, I worked them specifically to run ethanol fuel rather than race gas. BIG difference in power on gasoline, a mileage difference on ethanol, its gonna run roughly the same with the crossover or not on ethanol because it vaporizes and cools the intake charge regardless. Gasoline wants to be cold, it doesn't have good cooling and it likes to ignite when it feels like it due to heat, like diesel does. On pump gas I don't block the crossover, race gas I will, and on ethanol its mostly irrelevant... other than mileage. Ethanol boils at 173F at sea level. Gasoline components have boiling points between 80F and 450F, the mix of components makes a difference in how easily gasoline vaporizes. The mix changes season to season, they sell lighter stuff in winter, and by region. The gas you get in Montana is not even close to the gas you get in Florida. Back in 2000 I drove my 70 GTO from Nebraska to South Carolina, a 24 hour drive I did only stopping for gas. When I got to SC I had to retune everything, the carb, timing, and I had to put a bigger radiator in. Nebraska gets hotter and more humid in summer than South Carolina, so it wasn't that. The difference was the gasoline mix. I made the drive in February, so the gasoline was VERY different in Nebraska, but I rarely changed the carb and timing driving that car around for 5 years running pump gas. I drove the GTO around Charleston for the next 4 years. Coming to Michigan with it, the elevation is between 666ft and 1100ft above sea level. The GTO ran fine here on pump gas, buty also this far north we rarely get 90F to 110F days, unlike Nebraska and SC.. The gasoline here is very different from either of those other places I lived. Add pressure to things and boiling points go up, less pressure boiling points go down. Basic physics. Boiling point is where it starts to vaporize, and if it does that in the fuel line, you get bubbles and your engine won't start. The other thing about Nebraska to South Carolina is where I lived in Nebraska its 2000 feet above sea level. Charleston SC where I was stationed, is 15 feet above sea level. That makes a difference in gasoline and tuning too. Where you live matters, gasoline isn't the same everywhere you go. On the other side, ethanol is the same everywhere you go, because its one thing, not a mix of several things like gasoline is. What 10% ethanol does is improve the gasoline so much that they can sell you the lighter stuff that runs poorly without ethanol in it. That makes it evaporate and vapor lock much worse. I have zero issues with vapor lock on my E85 engines. I have lots of issues with pump gas sitting around now, but not E85. The GTO started no problem on E85 this spring, it has half a tank from last year. I should clean the carb on the Cuda, it wasn't running right last year, only the second year with a new Demon carb on it. The Cuda is the only pump gas muscle car I have.

[@WhiteTrashMotorsports]

Your knowledge of fuels has helped a lot of people enjoy their cars. I only run e85 in my turbo ls setup it's a true shame that people dismiss ethanol because of misinformation.

[@MrWill73]

All my cars are blocked and haul ass. That’s a proven trick forever. Most people don’t f**k with corn and a carb. Half 93 and 105 VP

[@wildrosegarage4208]

I have never had them do anything for me other than hot start issues, bake oil to the bottom of the intake and burn holes through aluminum ones. Edelbrock makes intakes like the performer rpm air gap which is designed to keep plenum and runners cool as possible and I would say 99% of those who run them run pump gas. You would think with all the dyno time put into a intake like that if it was not a good idea they would not have built it as they did. I am also surprised that after all your testing that aftermarket cylinder heads dont have a cross over. If you enjoy them thats great but you wont see anything leaving this garage with them. Thanks for watching.

[@wildrosegarage4208]

@@WhiteTrashMotorsports I bet it does work great for boosted or very high compression. We don't have e85 here but I could see it being great for that kind of setup. I only have experience with methanol in my diesel truck and some boosted cars. And just a snowperformance water meth kit worked great in them. Lowered egt's and stopped pinging. Thanks for watching.

[@wildrosegarage4208]

@@MrWill73 I dont think there is to many cars at the track with cross overs or many after market heads with them. As for E85 I can see it working well in very high compression motors or boosted motors as a alternative to pump gas. But you would need a fuel system the plays well with E85. Also I know for a fact that fuel mileage will drop on e85 compared to gas another reason it is cheap. It is great for people who can run it but I think it was some hippys screw up to go green. Takes a hole lot of corn to turn into alcohol makes sense if your making it to drink not so much to burn going down the road. I would rather have moonshine in a jar , corn on my plate and gas in my tank.