Thread: Using AFR 195's with dome pistons......

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I putting together a warmed up small block, using the 1095 AFR's, comp ported, with 65cc chambers. Im putting in Probe SRS slugs, with a small .175" dome to get the compression up where i want it.....
Has anyone used small domes with the AFR heads? I wondering how much mods will be needed to get the pistons compatible with the heads. The parts have not arrived yet, but will shortly. I put in a tech request and a call to AFR with no return yet.

call probe not afr as they make the piston they can tell you what chamber it should work with very common with the piston companys to list the pistons that will not clear some companys head chambers not a big deal so much with the SBC much more of a deal with the bbc . do not take anyones word anyways check it for room with the chamber you have

Yeah you're right........I will look them up and check it out. I'm of course gonna clay the motor during blueprint and see what I've g. I think with that small of a dome it might have a little issue near the plug. But its only .175 just enough to get me in the 11.25-11.3 range

Are you saying running 11.3's on pump gas??.

Yes.....somewhere in that neighborhood on the compression......using the right combo and cam selection this is very doable......have run many hot rods with numbers in this range without issues......heat may be the only one, due to the Coupe having a smaller radiator, but it is a 4-core, so maybe not too much of an issue....along with an oil cooler. Talking with AFR, Ive decided to just bite the bullet, shave the heads for a 58cc chamber and use flat tops, then no interference issues on that end. So.....need to cancel the domes and replace with the flats. Oh.....here in the southeast, 93 octane is the norm by the way

Originally Posted by Mohead1

..... Oh.....here in the southeast, 93 octane is the norm by the way

Mohead1, one thing I've learned recently is that the ethanol blends that the EPA tries to make mandatory start a process called "phase separation" within a week or two, and besides becoming more erosive one of the results of this process is that the fuel loses seven to eight percent on the octane scale - 93 octane becomes around 85 to 86. Doesn't affect the daily drivers so much, as they are replenishing burned fuel regularly, and their engines may not be as sensitive anyway; but our hot rods that get filled, then may sit for extended periods may well have fuel which is significantly lower quality. Around here finding the stations that offer 92/93 octane that is ethanol free is like finding hen's teeth. What worked in the past may not be viable in our changing world.

I understand the fuel degradation over time.....I dont let is sit for weeks at a time, I drive the car regularly.....so i will be turning the fuel over so to speak....im shooting for a certain dynamic compression between 7-8 to make this happen, but enough cam to make it run up in the top end.....we do have the E85 with good octane...but the issues with the ethanol arise (corrosion) and rubber degrading on hoses and such.....but ive run methanol race cars before, so i know the alchohol route too......

Sounds like you know the evils of ethanol in gasoline. Just mentioning it, as it's a real problem that can bite one in the butt.

I've run as high as 12.5 on E85 on the street in a heavy (3700 pounds) car with automatic and air on, still no problems with detonation. The one thing we do that we started years ago on drag cars is to install a small tank (4 gal) and just the cheapy Holley pump as an auxiliary system, with a couple gallons of race gas in it. When you're done racing for the day, turn on the valve from the gasoline tank, shut off the valve from the E-85 tank, and run the car long enough to get gas through the carb(s), then shut it off, through a shot of Sta-Bil in the E-85 tank, and put the car away for the week....

BTW, there is a fuel stabilizer on the market now made specifically for the 10% and 15% fuels, I put a 4 oz shot of it in ye 'ol shop truck (E-85) every time I fill it and don't have any problems with it either.....

Ethanol presents all the same headaches of dealing with it as methanol, just at a much lower cost....Still IMO E-85 is the best way to get away with a lot of compression in a street car!!!!!!

Ah......good info, Ive heard of the extra tank thing before....just never investigated it further.

The blue Sta-bil is make more for the E85 than the red.

Originally Posted by Dave Severson

BTW, there is a fuel stabilizer on the market now made specifically for the 10% and 15% fuels, I put a 4 oz shot of it in ye 'ol shop truck (E-85) every time I fill it and don't have any problems with it either.....

Ethanol presents all the same headaches of dealing with it as methanol, just at a much lower cost....Still IMO E-85 is the best way to get away with a lot of compression in a street car!!!!!!

Dave, are you talking about Gold Eagle's new Sta-Bil product specifically for ethanol blends, shown here - http://www.goldeagle.com/brands/stab...ducts.aspx#SET Looks like all three of their non-diesel additives (red/standard, blue/marine, orange?/ethanol) work with ethanol blends, but are earmarked to specific markets. Is there something you like better than the Sta-Bil? I'm thinking that having a bottle in the '33 would be a good idea for those times I can't get to my pure gasoline station.

I think in threads like this before what we concluded was SCR's of 9.5 on iron heads and just about 1 point more or 10.5 for aluminum heads with a DCR of 8.5. is a save bet given the variances of pump gas.That there have been guys push the DCR to 9.0,but that gets towards the ragged edge.That the possibility of headers covering up any noise detection is very real.Interesting Techinspector 1 posted tight quench helps prevent dentition as well.

Originally Posted by rspears

Dave, are you talking about Gold Eagle's new Sta-Bil product specifically for ethanol blends, shown here - Deprecated Browser Error Looks like all three of their non-diesel additives (red/standard, blue/marine, orange?/ethanol) work with ethanol blends, but are earmarked to specific markets. Is there something you like better than the Sta-Bil? I'm thinking that having a bottle in the '33 would be a good idea for those times I can't get to my pure gasoline station.

Yuppers, that's the stuff I use on the street. For the drag cars and Hot Rod stuff I use that and an equal shot of Lucas Fuel additive. On the street cars, even the Bonneville, I use 4 oz. of Sta Bil every fill up just as a preventative. Don't blame it all on the ethanol, either. Remember when all the gas pumps had a filter to catch the last bit of trash from the station's tank before it went in your car??? Not many of them around anymore, either!

Originally Posted by Dave Severson

Yuppers, that's the stuff I use on the street. For the drag cars and Hot Rod stuff I use that and an equal shot of Lucas Fuel additive. On the street cars, even the Bonneville, I use 4 oz. of Sta Bil every fill up just as a preventative. Don't blame it all on the ethanol, either. Remember when all the gas pumps had a filter to catch the last bit of trash from the station's tank before it went in your car??? Not many of them around anymore, either!

Yeah, I remember the filters, and agree they've been gone a long while. I also remember when the ethanol adder was a winter fuel event, and everyone wondered why their mileage dropped when it got cold. Easy answer, less BTU/LB in ethanol compared to gasoline, thus less efficiency. I just wish that we could let ethanol carry it's own weight without any government edicts about adding it to gasoline, and especially without any subsidies on the price of ethanol. Let it float on the free market and it would become a race fuel.

Sorry for the thread hijack, Mohead1 . I'll defer any more comments other than on-topic, even though I learned some things today, and that's a good thing!!